Squashed 'third_party/pi/' content from commit d981de122

git-subtree-dir: third_party/pi
git-subtree-split: d981de1229ef899957bbe968bc8dcda02a21f477

packages/coding-agent/test/suite/README.md

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+# Coding agent suite tests
+
+Use `test/suite/` for the new harness-based test suite around `AgentSession` and `AgentSessionRuntime`.
+
+Rules:
+- Use `test/suite/harness.ts`
+- Use the faux provider from `packages/ai/src/providers/faux.ts`
+- Do not use real provider APIs, real API keys, network calls, or paid tokens
+- Keep these tests CI-safe and deterministic
+- Do not use or extend the legacy `test/test-harness.ts` path unless a missing capability forces it

packages/coding-agent/test/suite/agent-session-bash-persistence.test.ts

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+import { Buffer } from "node:buffer";
+import type { AgentTool } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import type { BashOperations } from "../../src/core/tools/bash.ts";
+import { createHarness, type Harness } from "./harness.ts";
+
+function getEntryTypes(harness: Harness): string[] {
+	return harness.sessionManager.getEntries().map((entry) => entry.type);
+}
+
+interface ControlledBashInvocation {
+	signal: AbortSignal | undefined;
+	finish: () => void;
+}
+
+function createControlledBashOperations(invocations: ControlledBashInvocation[]): BashOperations {
+	return {
+		exec: async (_command, _cwd, options) => {
+			return await new Promise<{ exitCode: number | null }>((resolve) => {
+				invocations.push({
+					signal: options.signal,
+					finish: () => resolve({ exitCode: 0 }),
+				});
+			});
+		},
+	};
+}
+
+describe("AgentSession bash and persistence characterization", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("records bash results immediately while idle", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+
+		harness.session.recordBashResult("echo hi", {
+			output: "hi",
+			exitCode: 0,
+			cancelled: false,
+			truncated: false,
+		});
+
+		expect(harness.session.hasPendingBashMessages).toBe(false);
+		expect(harness.session.messages[harness.session.messages.length - 1]?.role).toBe("bashExecution");
+		expect(getEntryTypes(harness)).toContain("message");
+	});
+
+	it("defers bash results while streaming and flushes them before the next prompt", async () => {
+		let releaseToolExecution: (() => void) | undefined;
+		const toolRelease = new Promise<void>((resolve) => {
+			releaseToolExecution = resolve;
+		});
+		const waitTool: AgentTool = {
+			name: "wait",
+			label: "Wait",
+			description: "Wait for release",
+			parameters: Type.Object({}),
+			execute: async () => {
+				await toolRelease;
+				return {
+					content: [{ type: "text", text: "released" }],
+					details: {},
+				};
+			},
+		};
+		const harness = await createHarness({ tools: [waitTool] });
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage([fauxToolCall("wait", {})], { stopReason: "toolUse" }),
+			fauxAssistantMessage("done"),
+			fauxAssistantMessage("after flush"),
+		]);
+
+		const sawToolStart = new Promise<void>((resolve) => {
+			const unsubscribe = harness.session.subscribe((event) => {
+				if (event.type === "tool_execution_start") {
+					unsubscribe();
+					resolve();
+				}
+			});
+		});
+
+		const firstPrompt = harness.session.prompt("start");
+		await sawToolStart;
+		harness.session.recordBashResult("echo hi", {
+			output: "hi",
+			exitCode: 0,
+			cancelled: false,
+			truncated: false,
+		});
+
+		expect(harness.session.hasPendingBashMessages).toBe(true);
+		expect(harness.session.messages.some((message) => message.role === "bashExecution")).toBe(false);
+
+		releaseToolExecution?.();
+		await firstPrompt;
+
+		expect(harness.session.hasPendingBashMessages).toBe(false);
+		expect(harness.session.messages.some((message) => message.role === "bashExecution")).toBe(true);
+
+		await harness.session.prompt("next turn");
+
+		expect(harness.session.hasPendingBashMessages).toBe(false);
+		expect(harness.session.messages.some((message) => message.role === "bashExecution")).toBe(true);
+		expect(getEntryTypes(harness).filter((type) => type === "message").length).toBeGreaterThan(0);
+	});
+
+	it("executes bash commands and records the result", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+
+		const result = await harness.session.executeBash("printf 'hello'");
+
+		expect(result.output).toContain("hello");
+		expect(harness.session.messages[harness.session.messages.length - 1]?.role).toBe("bashExecution");
+	});
+
+	it("cancels running bash commands with abortBash", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		const operations: BashOperations = {
+			exec: async (_command, _cwd, options) => {
+				return await new Promise<{ exitCode: number | null }>((_resolve, reject) => {
+					options.signal?.addEventListener(
+						"abort",
+						() => {
+							reject(new Error("aborted"));
+						},
+						{ once: true },
+					);
+				});
+			},
+		};
+
+		const bashPromise = harness.session.executeBash("sleep", undefined, { operations });
+		await new Promise((resolve) => setTimeout(resolve, 0));
+		expect(harness.session.isBashRunning).toBe(true);
+		harness.session.abortBash();
+
+		const result = await bashPromise;
+		expect(result.cancelled).toBe(true);
+		expect(harness.session.isBashRunning).toBe(false);
+	});
+
+	it("keeps newer bash execution tracked when an older execution finishes", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		const invocations: ControlledBashInvocation[] = [];
+		const operations = createControlledBashOperations(invocations);
+
+		const firstBash = harness.session.executeBash("first", undefined, { operations });
+		const secondBash = harness.session.executeBash("second", undefined, { operations });
+
+		invocations[0].finish();
+		const firstResult = await firstBash;
+		const runningAfterFirstSettles = harness.session.isBashRunning;
+
+		harness.session.abortBash();
+		const secondWasAborted = invocations[1].signal?.aborted;
+		invocations[1].finish();
+		const secondResult = await secondBash;
+
+		expect(firstResult.cancelled).toBe(false);
+		expect(runningAfterFirstSettles).toBe(true);
+		expect(secondWasAborted).toBe(true);
+		expect(secondResult.cancelled).toBe(true);
+		expect(harness.session.isBashRunning).toBe(false);
+	});
+
+	it("aborts all active bash executions", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		const invocations: ControlledBashInvocation[] = [];
+		const operations = createControlledBashOperations(invocations);
+
+		const firstBash = harness.session.executeBash("first", undefined, { operations });
+		const secondBash = harness.session.executeBash("second", undefined, { operations });
+
+		harness.session.abortBash();
+		const abortedSignals = invocations.map((invocation) => invocation.signal?.aborted);
+		for (const invocation of invocations) {
+			invocation.finish();
+		}
+		const results = await Promise.all([firstBash, secondBash]);
+
+		expect(abortedSignals).toEqual([true, true]);
+		expect(results.map((result) => result.cancelled)).toEqual([true, true]);
+		expect(harness.session.isBashRunning).toBe(false);
+	});
+
+	it("persists user, assistant, toolResult, and custom messages in order", async () => {
+		const echoTool: AgentTool = {
+			name: "echo",
+			label: "Echo",
+			description: "Echo text back",
+			parameters: Type.Object({ text: Type.String() }),
+			execute: async (_toolCallId, params) => {
+				const text = typeof params === "object" && params !== null && "text" in params ? String(params.text) : "";
+				return { content: [{ type: "text", text: `echo:${text}` }], details: { text } };
+			},
+		};
+		const harness = await createHarness({ tools: [echoTool] });
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage([fauxToolCall("echo", { text: "hello" })], { stopReason: "toolUse" }),
+			fauxAssistantMessage("done"),
+		]);
+
+		await harness.session.sendCustomMessage({
+			customType: "note",
+			content: "hello",
+			display: true,
+			details: { a: 1 },
+		});
+		await harness.session.prompt("start");
+
+		const entries = harness.sessionManager.getEntries();
+		expect(entries.map((entry) => entry.type)).toEqual([
+			"custom_message",
+			"message",
+			"message",
+			"message",
+			"message",
+		]);
+		expect(harness.session.messages.map((message) => message.role)).toEqual([
+			"custom",
+			"user",
+			"assistant",
+			"toolResult",
+			"assistant",
+		]);
+	});
+
+	it("does not emit message_end for bash execution messages", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		const messageEndRoles: string[] = [];
+		harness.session.subscribe((event) => {
+			if (event.type === "message_end") {
+				messageEndRoles.push(event.message.role);
+			}
+		});
+
+		harness.session.recordBashResult("echo hi", {
+			output: "hi",
+			exitCode: 0,
+			cancelled: false,
+			truncated: false,
+		});
+
+		expect(messageEndRoles).toEqual([]);
+	});
+
+	it("persists aborted assistant messages", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("x".repeat(20_000))]);
+
+		const sawMessageUpdate = new Promise<void>((resolve) => {
+			const unsubscribe = harness.session.subscribe((event) => {
+				if (event.type === "message_update") {
+					unsubscribe();
+					resolve();
+				}
+			});
+		});
+
+		const promptPromise = harness.session.prompt("hi");
+		await sawMessageUpdate;
+		await harness.session.abort();
+		await promptPromise;
+
+		const lastEntry = harness.sessionManager.getEntries()[harness.sessionManager.getEntries().length - 1];
+		expect(lastEntry?.type).toBe("message");
+		if (lastEntry?.type === "message") {
+			expect(lastEntry.message.role).toBe("assistant");
+			if (lastEntry.message.role === "assistant") {
+				expect(lastEntry.message.stopReason).toBe("aborted");
+			}
+		}
+	});
+
+	it("records bash output through custom operations", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		const operations: BashOperations = {
+			exec: async (_command, _cwd, options) => {
+				options.onData(Buffer.from("hello from custom ops"));
+				return { exitCode: 0 };
+			},
+		};
+
+		const result = await harness.session.executeBash("custom", undefined, { operations });
+
+		expect(result.output).toContain("hello from custom ops");
+		expect(harness.session.messages[harness.session.messages.length - 1]?.role).toBe("bashExecution");
+	});
+
+	it("streams bash output to the callback and session events", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		const callbackDeltas: string[] = [];
+		const eventUpdates: Array<{ id: string | undefined; delta: string }> = [];
+		const unsubscribe = harness.session.subscribe((event) => {
+			if (event.type === "bash_execution_update") {
+				eventUpdates.push({ id: event.id, delta: event.delta });
+			}
+		});
+		const operations: BashOperations = {
+			exec: async (_command, _cwd, options) => {
+				options.onData(Buffer.from("hello "));
+				options.onData(Buffer.from("world"));
+				return { exitCode: 0 };
+			},
+		};
+
+		await harness.session.executeBash("custom", (delta) => callbackDeltas.push(delta), {
+			id: "bash-1",
+			operations,
+		});
+		unsubscribe();
+
+		expect(callbackDeltas).toEqual(["hello ", "world"]);
+		expect(eventUpdates).toEqual([
+			{ id: "bash-1", delta: "hello " },
+			{ id: "bash-1", delta: "world" },
+		]);
+	});
+});

packages/coding-agent/test/suite/agent-session-compaction.test.ts

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+import type { AgentMessage, AgentTool } from "@earendil-works/pi-agent-core";
+import {
+	type AssistantMessage,
+	type Context,
+	createAssistantMessageEventStream,
+	fauxAssistantMessage,
+	fauxToolCall,
+	type Model,
+	type SimpleStreamOptions,
+} from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { estimateTokens } from "../../src/core/compaction/index.ts";
+import { createHarness, getUserTexts, type Harness } from "./harness.ts";
+
+type SessionWithCompactionInternals = {
+	_checkCompaction: (assistantMessage: AssistantMessage, skipAbortedCheck?: boolean) => Promise<boolean>;
+	_runAutoCompaction: (reason: "overflow" | "threshold", willRetry: boolean) => Promise<boolean>;
+};
+
+function createUsage(totalTokens: number) {
+	return {
+		input: totalTokens,
+		output: 0,
+		cacheRead: 0,
+		cacheWrite: 0,
+		totalTokens,
+		cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+	};
+}
+
+function createAssistant(
+	harness: Harness,
+	options: {
+		stopReason?: AssistantMessage["stopReason"];
+		errorMessage?: string;
+		totalTokens?: number;
+		timestamp?: number;
+	},
+): AssistantMessage {
+	const model = harness.getModel();
+	return {
+		...fauxAssistantMessage("", {
+			stopReason: options.stopReason,
+			errorMessage: options.errorMessage,
+			timestamp: options.timestamp,
+		}),
+		api: model.api,
+		provider: model.provider,
+		model: model.id,
+		usage: createUsage(options.totalTokens ?? 0),
+	};
+}
+
+function useSummaryStreamFn(
+	harness: Harness,
+	summary: string,
+	onRequest?: (context: Context, options: SimpleStreamOptions | undefined) => void,
+): () => number {
+	let callCount = 0;
+	harness.session.agent.streamFunction = (model, context, options) => {
+		callCount++;
+		onRequest?.(context, options);
+		const stream = createAssistantMessageEventStream();
+		queueMicrotask(() => {
+			const message: AssistantMessage = {
+				...fauxAssistantMessage(summary),
+				api: model.api,
+				provider: model.provider,
+				model: model.id,
+				usage: createUsage(10),
+			};
+			stream.push({ type: "done", reason: "stop", message });
+		});
+		return stream;
+	};
+	return () => callCount;
+}
+
+function seedCompactableSession(harness: Harness): void {
+	harness.settingsManager.applyOverrides({ compaction: { keepRecentTokens: 1 } });
+	const now = Date.now();
+	harness.sessionManager.appendMessage({
+		role: "user",
+		content: [{ type: "text", text: "message to compact" }],
+		timestamp: now - 1000,
+	});
+	const assistant = createAssistant(harness, {
+		stopReason: "stop",
+		totalTokens: 100,
+		timestamp: now - 500,
+	});
+	assistant.content = [{ type: "text", text: "assistant response to compact" }];
+	harness.sessionManager.appendMessage(assistant);
+	harness.session.agent.state.messages = harness.sessionManager.buildSessionContext().messages;
+}
+
+async function createAbortableCompactionHarness(): Promise<{
+	harness: Harness;
+	compactionStarted: Promise<void>;
+}> {
+	let markCompactionStarted = () => {};
+	const compactionStarted = new Promise<void>((resolve) => {
+		markCompactionStarted = resolve;
+	});
+	const harness = await createHarness({
+		settings: { compaction: { keepRecentTokens: 1 } },
+		extensionFactories: [
+			(pi) => {
+				pi.on("session_before_compact", async (event) => {
+					return await new Promise<{ cancel: true }>((resolve) => {
+						event.signal.addEventListener("abort", () => resolve({ cancel: true }), { once: true });
+						markCompactionStarted();
+					});
+				});
+			},
+		],
+	});
+	seedCompactableSession(harness);
+	return { harness, compactionStarted };
+}
+
+describe("AgentSession compaction characterization", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		vi.useRealTimers();
+		vi.restoreAllMocks();
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("manually compacts using an extension-provided summary", async () => {
+		const summaryUsage = {
+			input: 10,
+			output: 20,
+			cacheRead: 30,
+			cacheWrite: 40,
+			totalTokens: 100,
+			cost: { input: 0.1, output: 0.2, cacheRead: 0.3, cacheWrite: 0.4, total: 1 },
+		};
+		const harness = await createHarness({
+			settings: { compaction: { keepRecentTokens: 1 } },
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_compact", async (event) => ({
+						compaction: {
+							summary: "summary from extension",
+							firstKeptEntryId: event.preparation.firstKeptEntryId,
+							tokensBefore: event.preparation.tokensBefore,
+							usage: summaryUsage,
+							details: { source: "extension" },
+						},
+					}));
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		await harness.session.prompt("one");
+		await harness.session.prompt("two");
+		const statsBefore = harness.session.getSessionStats();
+
+		const result = await harness.session.compact();
+		const compactionEntries = harness.sessionManager.getEntries().filter((entry) => entry.type === "compaction");
+		const estimatedTokensAfter = harness.session.messages.reduce((sum, message) => sum + estimateTokens(message), 0);
+
+		expect(result.summary).toBe("summary from extension");
+		expect(result.usage).toEqual(summaryUsage);
+		expect(result.estimatedTokensAfter).toBe(estimatedTokensAfter);
+		expect(compactionEntries).toHaveLength(1);
+		const compactionEntry = compactionEntries[0];
+		if (compactionEntry?.type === "compaction") {
+			expect(compactionEntry.usage).toEqual(summaryUsage);
+		}
+		const statsAfter = harness.session.getSessionStats();
+		expect(statsAfter.tokens.input).toBe(statsBefore.tokens.input + summaryUsage.input);
+		expect(statsAfter.tokens.output).toBe(statsBefore.tokens.output + summaryUsage.output);
+		expect(statsAfter.tokens.cacheRead).toBe(statsBefore.tokens.cacheRead + summaryUsage.cacheRead);
+		expect(statsAfter.tokens.cacheWrite).toBe(statsBefore.tokens.cacheWrite + summaryUsage.cacheWrite);
+		expect(statsAfter.cost).toBe(statsBefore.cost + summaryUsage.cost.total);
+		expect(harness.session.messages[0]?.role).toBe("compactionSummary");
+	});
+
+	it("allows a queued prompt to start when manual compaction ends", async () => {
+		const harness = await createHarness({
+			settings: { compaction: { keepRecentTokens: 1 } },
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_compact", async (event) => ({
+						compaction: {
+							summary: "manual compacted",
+							firstKeptEntryId: event.preparation.firstKeptEntryId,
+							tokensBefore: event.preparation.tokensBefore,
+							details: {},
+						},
+					}));
+				},
+			],
+		});
+		harnesses.push(harness);
+		seedCompactableSession(harness);
+		harness.setResponses([fauxAssistantMessage("queued response")]);
+
+		let queuedPrompt: Promise<void> | undefined;
+		harness.session.subscribe((event) => {
+			if (event.type === "compaction_end" && event.reason === "manual" && event.result) {
+				expect(harness.session.isCompacting).toBe(false);
+				queuedPrompt = harness.session.prompt("queued after compaction");
+			}
+		});
+
+		await harness.session.compact();
+		if (!queuedPrompt) throw new Error("compaction_end did not start the queued prompt");
+		await queuedPrompt;
+
+		expect(getUserTexts(harness)).toContain("queued after compaction");
+		expect(harness.session.getLastAssistantText()).toBe("queued response");
+	});
+
+	it("throws when compacting without a model", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		harness.session.agent.state.model = undefined as unknown as Model<any>;
+
+		await expect(harness.session.compact()).rejects.toThrow("No model selected");
+	});
+
+	it("throws when compacting without configured auth", async () => {
+		const harness = await createHarness({ withConfiguredAuth: false });
+		harnesses.push(harness);
+
+		await expect(harness.session.compact()).rejects.toThrow(`No API key found for ${harness.getModel().provider}.`);
+	});
+
+	it("manually compacts with a custom streamFn when registry auth is absent", async () => {
+		const harness = await createHarness({ withConfiguredAuth: false });
+		harnesses.push(harness);
+		seedCompactableSession(harness);
+		const getStreamCallCount = useSummaryStreamFn(harness, "summary from custom stream");
+
+		const result = await harness.session.compact();
+
+		expect(result.summary).toContain("summary from custom stream");
+		expect(getStreamCallCount()).toBe(1);
+	});
+
+	it("manually compacts with provider-resolved bearer auth", async () => {
+		const harness = await createHarness({ withConfiguredAuth: false });
+		harnesses.push(harness);
+		const model = harness.getModel();
+		harness.session.modelRuntime.registerNativeProvider({
+			id: model.provider,
+			name: "Faux bearer provider",
+			auth: {
+				apiKey: {
+					name: "Faux bearer token",
+					resolve: async () => ({
+						auth: { headers: { Authorization: "Bearer ambient-token" } },
+						source: "ambient bearer token",
+					}),
+				},
+			},
+			getModels: () => harness.models,
+			stream: () => createAssistantMessageEventStream(),
+			streamSimple: () => createAssistantMessageEventStream(),
+		});
+		seedCompactableSession(harness);
+		harness.setResponses([
+			(_context, options) => {
+				expect(options?.apiKey).toBeUndefined();
+				expect(options?.headers).toEqual({ Authorization: "Bearer ambient-token" });
+				return fauxAssistantMessage("summary with bearer auth");
+			},
+		]);
+
+		const result = await harness.session.compact();
+
+		expect(result.summary).toContain("summary with bearer auth");
+		expect(harness.faux.state.callCount).toBe(1);
+	});
+
+	it("uses the standalone compaction request context", async () => {
+		const harness = await createHarness({ settings: { compaction: { keepRecentTokens: 1 } } });
+		harnesses.push(harness);
+		seedCompactableSession(harness);
+
+		const transformContext = vi.fn(async (messages: AgentMessage[]) => messages);
+		harness.session.agent.transformContext = transformContext;
+		harness.session.agent.sessionId = "active-routing-session";
+		harness.session.agent.transport = "websocket";
+
+		let requestContext: Context | undefined;
+		let requestOptions: SimpleStreamOptions | undefined;
+		useSummaryStreamFn(harness, "standalone summary", (context, options) => {
+			requestContext = context;
+			requestOptions = options;
+		});
+
+		await harness.session.compact();
+
+		expect(transformContext).not.toHaveBeenCalled();
+		expect(requestContext?.systemPrompt).not.toBe(harness.session.agent.state.systemPrompt);
+		expect(requestContext?.tools).toBeUndefined();
+		expect(JSON.stringify(requestContext?.messages)).toContain("<conversation>");
+		expect(requestOptions).toMatchObject({ cacheRetention: "none" });
+		expect(requestOptions?.sessionId).not.toBe("active-routing-session");
+		expect(requestOptions?.transport).toBeUndefined();
+	});
+
+	it("persists usage from pi-generated manual compaction", async () => {
+		const harness = await createHarness({ withConfiguredAuth: false });
+		harnesses.push(harness);
+		seedCompactableSession(harness);
+		useSummaryStreamFn(harness, "summary from custom stream");
+
+		const result = await harness.session.compact();
+
+		const compactionEntries = harness.sessionManager.getEntries().filter((entry) => entry.type === "compaction");
+		expect(result.usage).toEqual(createUsage(10));
+		expect(compactionEntries).toHaveLength(1);
+		expect(compactionEntries[0]?.type === "compaction" ? compactionEntries[0].usage : undefined).toEqual(
+			createUsage(10),
+		);
+	});
+
+	it("auto-compacts with a custom streamFn when registry auth is absent", async () => {
+		const harness = await createHarness({ withConfiguredAuth: false });
+		harnesses.push(harness);
+		seedCompactableSession(harness);
+		const getStreamCallCount = useSummaryStreamFn(harness, "auto summary from custom stream");
+		const sessionInternals = harness.session as unknown as SessionWithCompactionInternals;
+
+		await sessionInternals._runAutoCompaction("threshold", false);
+
+		const compactionEntries = harness.sessionManager.getEntries().filter((entry) => entry.type === "compaction");
+		const compactionEnd = harness.eventsOfType("compaction_end").at(-1);
+		expect(compactionEntries).toHaveLength(1);
+		expect(compactionEnd?.result?.estimatedTokensAfter).toBeGreaterThan(0);
+		expect(getStreamCallCount()).toBe(1);
+	});
+
+	it("notifies extensions when auto-compaction fails", async () => {
+		const failedEvents: Array<{
+			reason: "manual" | "threshold" | "overflow";
+			errorMessage?: string;
+			aborted: boolean;
+			willRetry: boolean;
+			fromExtension: boolean;
+		}> = [];
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_compact_failed", async (event) => {
+						failedEvents.push(event);
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		seedCompactableSession(harness);
+		harness.session.agent.streamFunction = () => {
+			throw new Error("summary generator blew up");
+		};
+		const sessionInternals = harness.session as unknown as SessionWithCompactionInternals;
+
+		await expect(sessionInternals._runAutoCompaction("threshold", false)).resolves.toBe(false);
+
+		expect(harness.eventsOfType("compaction_end").at(-1)).toMatchObject({
+			reason: "threshold",
+			aborted: false,
+			willRetry: false,
+			errorMessage: "Auto-compaction failed: summary generator blew up",
+		});
+		expect(failedEvents).toEqual([
+			expect.objectContaining({
+				type: "session_compact_failed",
+				reason: "threshold",
+				aborted: false,
+				willRetry: false,
+				fromExtension: false,
+				errorMessage: "Auto-compaction failed: summary generator blew up",
+			}),
+		]);
+	});
+
+	it("compacts and resumes after a length stop below the desired output limit", async () => {
+		const harness = await createHarness({
+			models: [{ id: "faux-1", contextWindow: 1000, maxTokens: 100 }],
+			settings: { compaction: { keepRecentTokens: 1, reserveTokens: 0 } },
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_compact", async (event) => ({
+						compaction: {
+							summary: "overflow compacted",
+							firstKeptEntryId: event.preparation.firstKeptEntryId,
+							tokensBefore: event.preparation.tokensBefore,
+							details: {},
+						},
+					}));
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage("partial response", { stopReason: "length" }),
+			fauxAssistantMessage("completed response"),
+		]);
+
+		await harness.session.prompt("x".repeat(5000));
+
+		expect(harness.faux.state.callCount).toBe(2);
+		expect(harness.eventsOfType("compaction_end").at(-1)).toMatchObject({
+			reason: "overflow",
+			aborted: false,
+			willRetry: true,
+		});
+		expect(harness.session.getLastAssistantText()).toBe("completed response");
+	});
+
+	it("compacts after a tool result before the next assistant request in the same run", async () => {
+		const toolResult = `large-tool-result:${"x".repeat(6800)}`;
+		const largeTool: AgentTool = {
+			name: "large_result",
+			label: "Large result",
+			description: "Returns enough content to cross the compaction threshold",
+			parameters: Type.Object({}),
+			execute: async () => ({ content: [{ type: "text", text: toolResult }], details: {} }),
+		};
+		const order: string[] = [];
+		const harness = await createHarness({
+			models: [{ id: "faux-1", contextWindow: 2600, maxTokens: 100 }],
+			settings: { compaction: { enabled: true, reserveTokens: 400, keepRecentTokens: 1750 } },
+			tools: [largeTool],
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_compact", (event) => {
+						order.push("compaction");
+						return {
+							compaction: {
+								summary: "compacted history",
+								firstKeptEntryId: event.preparation.firstKeptEntryId,
+								tokensBefore: event.preparation.tokensBefore,
+								details: {},
+							},
+						};
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		let resumedRequest = "";
+		harness.setResponses([
+			fauxAssistantMessage(`old-history:${"a".repeat(800)}`),
+			fauxAssistantMessage(`recent-history:${"b".repeat(800)}`),
+			fauxAssistantMessage(fauxToolCall("large_result", {}), { stopReason: "toolUse" }),
+			(context) => {
+				order.push("provider");
+				resumedRequest = JSON.stringify(context.messages);
+				return fauxAssistantMessage("finished after compaction");
+			},
+		]);
+
+		await harness.session.prompt("seed old history");
+		await harness.session.prompt("seed recent history");
+		const agentStartsBefore = harness.eventsOfType("agent_start").length;
+		await harness.session.prompt("run the large tool");
+
+		expect(order).toEqual(["compaction", "provider"]);
+		expect(harness.eventsOfType("agent_start")).toHaveLength(agentStartsBefore + 1);
+		expect(harness.eventsOfType("compaction_start").at(-1)).toEqual({
+			type: "compaction_start",
+			reason: "threshold",
+		});
+		expect(resumedRequest).toContain("compacted history");
+		expect(resumedRequest).toContain("large-tool-result");
+		expect(harness.session.getLastAssistantText()).toBe("finished after compaction");
+	});
+
+	it("includes steering queued during compaction in the resumed assistant request", async () => {
+		const largeTool: AgentTool = {
+			name: "large_result",
+			label: "Large result",
+			description: "Returns enough content to cross the compaction threshold",
+			parameters: Type.Object({}),
+			execute: async () => ({
+				content: [{ type: "text", text: `large-tool-result:${"x".repeat(6800)}` }],
+				details: {},
+			}),
+		};
+		let markCompactionStarted = () => {};
+		const compactionStarted = new Promise<void>((resolve) => {
+			markCompactionStarted = resolve;
+		});
+		let releaseCompaction = () => {};
+		const compactionReleased = new Promise<void>((resolve) => {
+			releaseCompaction = resolve;
+		});
+		const harness = await createHarness({
+			models: [{ id: "faux-1", contextWindow: 2600, maxTokens: 100 }],
+			settings: { compaction: { enabled: true, reserveTokens: 400, keepRecentTokens: 1750 } },
+			tools: [largeTool],
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_compact", async (event) => {
+						markCompactionStarted();
+						await compactionReleased;
+						return {
+							compaction: {
+								summary: "compacted history",
+								firstKeptEntryId: event.preparation.firstKeptEntryId,
+								tokensBefore: event.preparation.tokensBefore,
+								details: {},
+							},
+						};
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		let resumedRequest = "";
+		harness.setResponses([
+			fauxAssistantMessage(`old-history:${"a".repeat(800)}`),
+			fauxAssistantMessage(`recent-history:${"b".repeat(800)}`),
+			fauxAssistantMessage(fauxToolCall("large_result", {}), { stopReason: "toolUse" }),
+			(context) => {
+				resumedRequest = JSON.stringify(context.messages);
+				return fauxAssistantMessage("finished after compaction");
+			},
+			fauxAssistantMessage("finished after delayed steering"),
+		]);
+
+		await harness.session.prompt("seed old history");
+		await harness.session.prompt("seed recent history");
+		const promptPromise = harness.session.prompt("run the large tool");
+		await compactionStarted;
+		await harness.session.steer("change direction");
+		releaseCompaction();
+		await promptPromise;
+
+		expect(resumedRequest).toContain("change direction");
+		expect(harness.faux.state.callCount).toBe(4);
+	});
+
+	it("does not compact after a terminating tool result", async () => {
+		const terminatingTool: AgentTool = {
+			name: "terminate_with_large_result",
+			label: "Terminate with large result",
+			description: "Returns enough content to cross the compaction threshold, then terminates",
+			parameters: Type.Object({}),
+			execute: async () => ({
+				content: [{ type: "text", text: `large-tool-result:${"x".repeat(6800)}` }],
+				details: {},
+				terminate: true,
+			}),
+		};
+		const harness = await createHarness({
+			models: [{ id: "faux-1", contextWindow: 2600, maxTokens: 100 }],
+			settings: { compaction: { enabled: true, reserveTokens: 400, keepRecentTokens: 1750 } },
+			tools: [terminatingTool],
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_compact", (event) => ({
+						compaction: {
+							summary: "unexpected compaction",
+							firstKeptEntryId: event.preparation.firstKeptEntryId,
+							tokensBefore: event.preparation.tokensBefore,
+							details: {},
+						},
+					}));
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage(`old-history:${"a".repeat(800)}`),
+			fauxAssistantMessage(`recent-history:${"b".repeat(800)}`),
+			fauxAssistantMessage(fauxToolCall("terminate_with_large_result", {}), { stopReason: "toolUse" }),
+		]);
+
+		await harness.session.prompt("seed old history");
+		await harness.session.prompt("seed recent history");
+		await harness.session.prompt("run the terminating tool");
+
+		expect(harness.eventsOfType("compaction_start")).toEqual([]);
+		expect(harness.sessionManager.getEntries().filter((entry) => entry.type === "compaction")).toEqual([]);
+		expect(harness.getPendingResponseCount()).toBe(0);
+	});
+
+	it("does not compact when a length stop reaches the desired output limit", async () => {
+		const harness = await createHarness({
+			models: [{ id: "faux-1", contextWindow: 1_000_000, maxTokens: 100 }],
+		});
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("x".repeat(400), { stopReason: "length" })]);
+
+		await harness.session.prompt("hello");
+
+		expect(harness.faux.state.callCount).toBe(1);
+		expect(harness.eventsOfType("compaction_start")).toHaveLength(0);
+	});
+
+	it("stops after one compact-and-retry when a second response is also truncated", async () => {
+		const harness = await createHarness({
+			models: [{ id: "faux-1", contextWindow: 1_000_000, maxTokens: 100 }],
+			settings: { compaction: { keepRecentTokens: 1, reserveTokens: 0 } },
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_compact", async (event) => ({
+						compaction: {
+							summary: "overflow compacted",
+							firstKeptEntryId: event.preparation.firstKeptEntryId,
+							tokensBefore: event.preparation.tokensBefore,
+							details: {},
+						},
+					}));
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			() => fauxAssistantMessage("x".repeat(64), { stopReason: "length", timestamp: Date.now() + 10_000 }),
+			() => fauxAssistantMessage("y".repeat(64), { stopReason: "length", timestamp: Date.now() + 10_000 }),
+		]);
+
+		await harness.session.prompt("x".repeat(5000));
+
+		expect(harness.faux.state.callCount).toBe(2);
+		expect(harness.eventsOfType("compaction_start").filter((event) => event.reason === "overflow")).toHaveLength(1);
+		expect(harness.eventsOfType("compaction_end").at(-1)?.errorMessage).toBe(
+			"Truncated response recovery failed after one compact-and-retry attempt.",
+		);
+	});
+
+	it("keeps overflow wording when a repeated length stop fills the context window", async () => {
+		const harness = await createHarness({
+			models: [{ id: "faux-1", contextWindow: 100, maxTokens: 100 }],
+		});
+		harnesses.push(harness);
+		const sessionInternals = harness.session as unknown as SessionWithCompactionInternals;
+		const lengthOverflowMessage = createAssistant(harness, {
+			stopReason: "length",
+			totalTokens: 100,
+			timestamp: Date.now(),
+		});
+		const runAutoCompactionSpy = vi.spyOn(sessionInternals, "_runAutoCompaction").mockResolvedValue(false);
+		const compactionErrors: string[] = [];
+		harness.session.subscribe((event) => {
+			if (event.type === "compaction_end" && event.errorMessage) {
+				compactionErrors.push(event.errorMessage);
+			}
+		});
+
+		await sessionInternals._checkCompaction(lengthOverflowMessage);
+		await sessionInternals._checkCompaction({ ...lengthOverflowMessage, timestamp: Date.now() + 1 });
+
+		expect(runAutoCompactionSpy).toHaveBeenCalledTimes(1);
+		expect(compactionErrors).toContain(
+			"Context overflow recovery failed after one compact-and-retry attempt. Try reducing context or switching to a larger-context model.",
+		);
+	});
+
+	it("cancels in-progress manual compaction when abortCompaction is called", async () => {
+		const { harness, compactionStarted } = await createAbortableCompactionHarness();
+		harnesses.push(harness);
+
+		const compactPromise = harness.session.compact();
+		const compactExpectation = expect(compactPromise).rejects.toThrow("Compaction cancelled");
+		await compactionStarted;
+		harness.session.abortCompaction();
+
+		await compactExpectation;
+	});
+
+	// Regression test for #8920.
+	it("aborts an in-progress manual compaction and waits until the session is idle", async () => {
+		const { harness, compactionStarted } = await createAbortableCompactionHarness();
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("continued")]);
+
+		const compactPromise = harness.session.compact();
+		const compactExpectation = expect(compactPromise).rejects.toThrow("Compaction cancelled");
+		await compactionStarted;
+		await harness.session.abort();
+		await compactExpectation;
+
+		expect(harness.eventsOfType("compaction_end").at(-1)).toMatchObject({
+			reason: "manual",
+			aborted: true,
+		});
+		expect(harness.session.isCompacting).toBe(false);
+		expect(harness.session.isIdle).toBe(true);
+
+		await expect(harness.session.prompt("next prompt")).resolves.toBeUndefined();
+		expect(harness.session.getLastAssistantText()).toBe("continued");
+	});
+
+	it("resumes after threshold compaction when only agent-level queued messages exist", async () => {
+		vi.useFakeTimers();
+		const harness = await createHarness({
+			settings: { compaction: { keepRecentTokens: 1 } },
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_compact", async (event) => ({
+						compaction: {
+							summary: "auto compacted",
+							firstKeptEntryId: event.preparation.firstKeptEntryId,
+							tokensBefore: event.preparation.tokensBefore,
+							details: {},
+						},
+					}));
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("one"), fauxAssistantMessage("two")]);
+		await harness.session.prompt("first");
+		await harness.session.prompt("second");
+
+		harness.session.agent.followUp({
+			role: "custom",
+			customType: "test",
+			content: [{ type: "text", text: "queued custom" }],
+			display: false,
+			timestamp: Date.now(),
+		});
+
+		const sessionInternals = harness.session as unknown as SessionWithCompactionInternals;
+
+		await expect(sessionInternals._runAutoCompaction("threshold", false)).resolves.toBe(true);
+	});
+
+	it("does not retry overflow recovery more than once", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		const sessionInternals = harness.session as unknown as SessionWithCompactionInternals;
+		const overflowMessage = createAssistant(harness, {
+			stopReason: "error",
+			errorMessage: "prompt is too long",
+			timestamp: Date.now(),
+		});
+		const runAutoCompactionSpy = vi.spyOn(sessionInternals, "_runAutoCompaction").mockResolvedValue(false);
+		const compactionErrors: string[] = [];
+		harness.session.subscribe((event) => {
+			if (event.type === "compaction_end" && event.errorMessage) {
+				compactionErrors.push(event.errorMessage);
+			}
+		});
+
+		await sessionInternals._checkCompaction(overflowMessage);
+		await sessionInternals._checkCompaction({ ...overflowMessage, timestamp: Date.now() + 1 });
+
+		expect(runAutoCompactionSpy).toHaveBeenCalledTimes(1);
+		expect(compactionErrors).toContain(
+			"Context overflow recovery failed after one compact-and-retry attempt. Try reducing context or switching to a larger-context model.",
+		);
+	});
+
+	it("compacts successful overflow responses without retrying", async () => {
+		const harness = await createHarness({
+			settings: { compaction: { enabled: true, keepRecentTokens: 1, reserveTokens: 0 } },
+			models: [{ id: "faux-1", contextWindow: 1, maxTokens: 100 }],
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_compact", async (event) => ({
+						compaction: {
+							summary: "successful overflow compacted",
+							firstKeptEntryId: event.preparation.firstKeptEntryId,
+							tokensBefore: event.preparation.tokensBefore,
+							details: {},
+						},
+					}));
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("completed answer")]);
+
+		await expect(harness.session.prompt("hello")).resolves.toBeUndefined();
+
+		const compactionEnd = harness.eventsOfType("compaction_end").at(-1);
+		expect(compactionEnd).toMatchObject({
+			reason: "overflow",
+			aborted: false,
+			willRetry: false,
+		});
+		expect(harness.faux.state.callCount).toBe(1);
+	});
+
+	it("ignores stale pre-compaction assistant usage on pre-prompt checks", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		const sessionInternals = harness.session as unknown as SessionWithCompactionInternals;
+		const staleTimestamp = Date.now() - 10_000;
+		const staleAssistant = createAssistant(harness, {
+			stopReason: "stop",
+			totalTokens: 610_000,
+			timestamp: staleTimestamp,
+		});
+
+		harness.sessionManager.appendMessage({
+			role: "user",
+			content: [{ type: "text", text: "before compaction" }],
+			timestamp: staleTimestamp - 1000,
+		});
+		harness.sessionManager.appendMessage(staleAssistant);
+		const firstKeptEntryId = harness.sessionManager.getEntries()[0]!.id;
+		harness.sessionManager.appendCompaction(
+			"summary",
+			firstKeptEntryId,
+			staleAssistant.usage.totalTokens,
+			undefined,
+			false,
+		);
+		harness.sessionManager.appendMessage({
+			role: "user",
+			content: [{ type: "text", text: "after compaction" }],
+			timestamp: Date.now(),
+		});
+
+		const runAutoCompactionSpy = vi.spyOn(sessionInternals, "_runAutoCompaction").mockResolvedValue(false);
+
+		await sessionInternals._checkCompaction(staleAssistant, false);
+
+		expect(runAutoCompactionSpy).not.toHaveBeenCalled();
+	});
+
+	it("triggers threshold compaction for error messages using the last successful usage", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		const sessionInternals = harness.session as unknown as SessionWithCompactionInternals;
+		const successfulAssistant = createAssistant(harness, {
+			stopReason: "stop",
+			totalTokens: 190_000,
+			timestamp: Date.now(),
+		});
+		const errorAssistant = createAssistant(harness, {
+			stopReason: "error",
+			errorMessage: "529 overloaded",
+			timestamp: Date.now() + 1000,
+		});
+		harness.session.agent.state.messages = [
+			{ role: "user", content: [{ type: "text", text: "hello" }], timestamp: Date.now() - 1000 },
+			successfulAssistant,
+			{ role: "user", content: [{ type: "text", text: "retry" }], timestamp: Date.now() + 500 },
+			errorAssistant,
+		];
+
+		const runAutoCompactionSpy = vi.spyOn(sessionInternals, "_runAutoCompaction").mockResolvedValue(false);
+
+		await sessionInternals._checkCompaction(errorAssistant);
+
+		expect(runAutoCompactionSpy).toHaveBeenCalledWith("threshold", false);
+	});
+
+	it("does not trigger threshold compaction for error messages when no prior usage exists", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		const sessionInternals = harness.session as unknown as SessionWithCompactionInternals;
+		const errorAssistant = createAssistant(harness, {
+			stopReason: "error",
+			errorMessage: "529 overloaded",
+			timestamp: Date.now(),
+		});
+		harness.session.agent.state.messages = [
+			{ role: "user", content: [{ type: "text", text: "hello" }], timestamp: Date.now() - 1000 },
+			errorAssistant,
+		];
+
+		const runAutoCompactionSpy = vi.spyOn(sessionInternals, "_runAutoCompaction").mockResolvedValue(false);
+
+		await sessionInternals._checkCompaction(errorAssistant);
+
+		expect(runAutoCompactionSpy).not.toHaveBeenCalled();
+	});
+
+	it("does not trigger threshold compaction when only kept pre-compaction usage exists", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		const sessionInternals = harness.session as unknown as SessionWithCompactionInternals;
+		const preCompactionTimestamp = Date.now() - 10_000;
+		const keptAssistant = createAssistant(harness, {
+			stopReason: "stop",
+			totalTokens: 190_000,
+			timestamp: preCompactionTimestamp,
+		});
+
+		harness.sessionManager.appendMessage({
+			role: "user",
+			content: [{ type: "text", text: "before compaction" }],
+			timestamp: preCompactionTimestamp - 1000,
+		});
+		harness.sessionManager.appendMessage(keptAssistant);
+		const firstKeptEntryId = harness.sessionManager.getEntries()[0]!.id;
+		harness.sessionManager.appendCompaction(
+			"summary",
+			firstKeptEntryId,
+			keptAssistant.usage.totalTokens,
+			undefined,
+			false,
+		);
+
+		const errorAssistant = createAssistant(harness, {
+			stopReason: "error",
+			errorMessage: "529 overloaded",
+			timestamp: Date.now(),
+		});
+		harness.session.agent.state.messages = [
+			{ role: "user", content: [{ type: "text", text: "kept user" }], timestamp: preCompactionTimestamp - 1000 },
+			keptAssistant,
+			{ role: "user", content: [{ type: "text", text: "new prompt" }], timestamp: Date.now() - 500 },
+			errorAssistant,
+		];
+
+		const runAutoCompactionSpy = vi.spyOn(sessionInternals, "_runAutoCompaction").mockResolvedValue(false);
+
+		await sessionInternals._checkCompaction(errorAssistant);
+
+		expect(runAutoCompactionSpy).not.toHaveBeenCalled();
+	});
+
+	it("does not trigger threshold compaction below the threshold or when disabled", async () => {
+		const belowThresholdHarness = await createHarness({
+			settings: { compaction: { enabled: true, reserveTokens: 1000 } },
+			models: [{ id: "faux-1", contextWindow: 200_000 }],
+		});
+		harnesses.push(belowThresholdHarness);
+		const disabledHarness = await createHarness({ settings: { compaction: { enabled: false } } });
+		harnesses.push(disabledHarness);
+
+		const belowThresholdInternals = belowThresholdHarness.session as unknown as SessionWithCompactionInternals;
+		const disabledInternals = disabledHarness.session as unknown as SessionWithCompactionInternals;
+		const belowThresholdSpy = vi.spyOn(belowThresholdInternals, "_runAutoCompaction").mockResolvedValue(false);
+		const disabledSpy = vi.spyOn(disabledInternals, "_runAutoCompaction").mockResolvedValue(false);
+
+		await belowThresholdInternals._checkCompaction(
+			createAssistant(belowThresholdHarness, { stopReason: "stop", totalTokens: 1_000, timestamp: Date.now() }),
+		);
+		await disabledInternals._checkCompaction(
+			createAssistant(disabledHarness, { stopReason: "stop", totalTokens: 1_000_000, timestamp: Date.now() }),
+		);
+
+		expect(belowThresholdSpy).not.toHaveBeenCalled();
+		expect(disabledSpy).not.toHaveBeenCalled();
+	});
+});

packages/coding-agent/test/suite/agent-session-model-extension.test.ts

@@ -0,0 +1,518 @@
+import type { AgentTool, ThinkingLevel } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall, type Model, type Usage } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import type { BuildSystemPromptOptions, ExtensionAPI } from "../../src/index.ts";
+import { createHarness, getAssistantTexts, type Harness } from "./harness.ts";
+
+describe("AgentSession model and extension characterization", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("setModel saves the model to the session and emits model_select", async () => {
+		const modelEvents: string[] = [];
+		const harness = await createHarness({
+			models: [
+				{ id: "faux-1", name: "One", reasoning: true },
+				{ id: "faux-2", name: "Two", reasoning: true },
+			],
+			extensionFactories: [
+				(pi) => {
+					pi.on("model_select", async (event) => {
+						modelEvents.push(`${event.previousModel?.id ?? "none"}->${event.model.id}:${event.source}`);
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		const nextModel = harness.getModel("faux-2")!;
+
+		await harness.session.setModel(nextModel);
+
+		expect(harness.session.model?.id).toBe("faux-2");
+		expect(modelEvents).toEqual(["faux-1->faux-2:set"]);
+		expect(
+			harness.sessionManager
+				.getEntries()
+				.filter((entry) => entry.type === "model_change")
+				.map((entry) => `${entry.provider}/${entry.modelId}`),
+		).toEqual([`${nextModel.provider}/${nextModel.id}`]);
+		expect(harness.settingsManager.getDefaultProvider()).toBeUndefined();
+		expect(harness.settingsManager.getDefaultModel()).toBeUndefined();
+	});
+
+	it("only persists model and thinking defaults when requested", async () => {
+		const harness = await createHarness({
+			models: [
+				{ id: "faux-1", name: "One", reasoning: true },
+				{ id: "faux-2", name: "Two", reasoning: true },
+			],
+		});
+		harnesses.push(harness);
+		const nextModel = harness.getModel("faux-2")!;
+
+		await harness.session.setModel(nextModel);
+		expect(harness.settingsManager.getDefaultProvider()).toBeUndefined();
+		expect(harness.settingsManager.getDefaultModel()).toBeUndefined();
+
+		harness.session.setThinkingLevel("low");
+		expect(harness.settingsManager.getDefaultThinkingLevel()).toBeUndefined();
+
+		await harness.session.setModel(nextModel, { persist: true });
+		expect(harness.settingsManager.getDefaultProvider()).toBe(nextModel.provider);
+		expect(harness.settingsManager.getDefaultModel()).toBe(nextModel.id);
+
+		harness.session.setThinkingLevel("high", { persist: true });
+		expect(harness.settingsManager.getDefaultThinkingLevel()).toBe("high");
+	});
+
+	it("persists the requested default thinking level even when the current model clamps it", async () => {
+		const harness = await createHarness({ models: [{ id: "faux-1", reasoning: true }] });
+		harnesses.push(harness);
+
+		harness.session.setThinkingLevel("max", { persist: true });
+
+		expect(harness.session.thinkingLevel).toBe("high");
+		expect(harness.settingsManager.getDefaultThinkingLevel()).toBe("max");
+	});
+
+	it("cycleModel and cycleThinkingLevel are session-only by default", async () => {
+		const harness = await createHarness({
+			models: [
+				{ id: "faux-1", name: "One", reasoning: true },
+				{ id: "faux-2", name: "Two", reasoning: true },
+			],
+			settings: {
+				defaultProvider: "faux",
+				defaultModel: "faux-1",
+				defaultThinkingLevel: "low",
+			},
+		});
+		harnesses.push(harness);
+
+		await harness.session.cycleModel();
+		expect(harness.session.model?.id).toBe("faux-2");
+		expect(harness.settingsManager.getDefaultModel()).toBe("faux-1");
+
+		harness.session.setThinkingLevel("off");
+		expect(harness.session.cycleThinkingLevel()).toBe("minimal");
+		expect(harness.settingsManager.getDefaultThinkingLevel()).toBe("low");
+	});
+
+	it("applies per-model thinking level override on model switch", async () => {
+		const harness = await createHarness({
+			models: [
+				{ id: "faux-1", name: "One", reasoning: true },
+				{ id: "faux-2", name: "Two", reasoning: true },
+			],
+			settings: { defaultThinkingLevel: "medium" },
+		});
+		harnesses.push(harness);
+
+		// Set a per-model override for faux-2
+		harness.settingsManager.setModelThinkingLevel("faux", "faux-2", "low");
+
+		// Session starts on faux-1 with default thinking
+		harness.session.setThinkingLevel("high");
+		expect(harness.session.thinkingLevel).toBe("high");
+
+		// Switch to faux-2 → per-model override should apply
+		const model2 = harness.getModel("faux-2")!;
+		await harness.session.setModel(model2);
+		expect(harness.session.thinkingLevel).toBe("low");
+
+		// Switch back to faux-1 → no per-model override, uses global default
+		const model1 = harness.getModel("faux-1")!;
+		await harness.session.setModel(model1);
+		expect(harness.session.thinkingLevel).toBe("medium");
+	});
+
+	it("falls back to current session thinking level when no per-model or global default is configured", async () => {
+		const harness = await createHarness({
+			models: [
+				{ id: "faux-1", name: "One", reasoning: true },
+				{ id: "faux-2", name: "Two", reasoning: true },
+			],
+		});
+		harnesses.push(harness);
+
+		harness.session.setThinkingLevel("high");
+		await harness.session.setModel(harness.getModel("faux-2")!);
+		expect(harness.session.thinkingLevel).toBe("high");
+	});
+
+	it("per-model override takes priority over global default during model switch", async () => {
+		const harness = await createHarness({
+			models: [
+				{ id: "faux-1", name: "One", reasoning: true },
+				{ id: "faux-2", name: "Two", reasoning: true },
+			],
+			settings: {
+				defaultThinkingLevel: "high",
+				modelThinkingLevels: { "faux/faux-2": "minimal" },
+			},
+		});
+		harnesses.push(harness);
+
+		// Start on a non-thinking model, then switch to faux-2
+		const model2 = harness.getModel("faux-2")!;
+		await harness.session.setModel(model2);
+		expect(harness.session.thinkingLevel).toBe("minimal");
+	});
+
+	it("cycles through scoped models and preserves the scoped thinking preference", async () => {
+		const harness = await createHarness({
+			models: [
+				{ id: "faux-1", name: "One", reasoning: true },
+				{ id: "faux-2", name: "Two", reasoning: false },
+			],
+		});
+		harnesses.push(harness);
+		const modelOne = harness.getModel("faux-1")!;
+		const modelTwo = harness.getModel("faux-2")!;
+		harness.session.setScopedModels([{ model: modelOne, thinkingLevel: "high" }, { model: modelTwo }] as Array<{
+			model: Model<string>;
+			thinkingLevel?: ThinkingLevel;
+		}>);
+		harness.session.setThinkingLevel("high");
+
+		await harness.session.cycleModel();
+		expect(harness.session.model?.id).toBe("faux-2");
+		expect(harness.session.thinkingLevel).toBe("off");
+
+		await harness.session.cycleModel();
+		expect(harness.session.model?.id).toBe("faux-1");
+		expect(harness.session.thinkingLevel).toBe("high");
+	});
+
+	it("clamps thinking levels to model capabilities and cycles available levels", async () => {
+		const harness = await createHarness({ models: [{ id: "faux-1", reasoning: false }] });
+		harnesses.push(harness);
+
+		harness.session.setThinkingLevel("high");
+		expect(harness.session.thinkingLevel).toBe("off");
+		expect(harness.session.cycleThinkingLevel()).toBeUndefined();
+	});
+
+	it("cycles xhigh before max when both are supported", async () => {
+		const harness = await createHarness({ models: [{ id: "faux-1", reasoning: true }] });
+		harnesses.push(harness);
+		harness.getModel().thinkingLevelMap = { xhigh: "xhigh", max: "max" };
+
+		expect(harness.session.getAvailableThinkingLevels()).toEqual([
+			"off",
+			"minimal",
+			"low",
+			"medium",
+			"high",
+			"xhigh",
+			"max",
+		]);
+		harness.session.setThinkingLevel("high");
+		expect(harness.session.cycleThinkingLevel()).toBe("xhigh");
+		expect(harness.session.cycleThinkingLevel()).toBe("max");
+		expect(harness.session.cycleThinkingLevel()).toBe("off");
+	});
+
+	it("throws when setModel is called without configured auth", async () => {
+		const harness = await createHarness({
+			models: [
+				{ id: "faux-1", name: "One", reasoning: true },
+				{ id: "faux-2", name: "Two", reasoning: true },
+			],
+			withConfiguredAuth: false,
+		});
+		harnesses.push(harness);
+
+		await expect(harness.session.setModel(harness.getModel("faux-2")!)).rejects.toThrow(
+			`No API key for ${harness.getModel().provider}/faux-2`,
+		);
+	});
+
+	it("allows extension tool_call handlers to block tool execution", async () => {
+		const echoTool: AgentTool = {
+			name: "echo",
+			label: "Echo",
+			description: "Echo text back",
+			parameters: Type.Object({ text: Type.String() }),
+			execute: async () => {
+				throw new Error("tool should have been blocked");
+			},
+		};
+		const harness = await createHarness({
+			tools: [echoTool],
+			extensionFactories: [
+				(pi) => {
+					pi.on("tool_call", async () => ({ block: true, reason: "Blocked by test" }));
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage([fauxToolCall("echo", { text: "hello" })], { stopReason: "toolUse" }),
+			(context) => {
+				const toolResult = context.messages.find((message) => message.role === "toolResult");
+				const errorText =
+					toolResult?.role === "toolResult"
+						? toolResult.content
+								.filter((part): part is { type: "text"; text: string } => part.type === "text")
+								.map((part) => part.text)
+								.join("\n")
+						: "";
+				return fauxAssistantMessage(errorText);
+			},
+		]);
+
+		await harness.session.prompt("hi");
+
+		expect(getAssistantTexts(harness)).toContain("Blocked by test");
+		expect(
+			harness.session.messages.find((message) => message.role === "toolResult" && message.isError),
+		).toBeDefined();
+	});
+
+	it("allows extension tool_result handlers to modify tool results", async () => {
+		const toolUsage: Usage = {
+			input: 1,
+			output: 2,
+			cacheRead: 3,
+			cacheWrite: 4,
+			totalTokens: 10,
+			cost: { input: 0.1, output: 0.2, cacheRead: 0.3, cacheWrite: 0.4, total: 1 },
+		};
+		const patchedToolUsage: Usage = {
+			input: 5,
+			output: 6,
+			cacheRead: 7,
+			cacheWrite: 8,
+			totalTokens: 26,
+			cost: { input: 0.5, output: 0.6, cacheRead: 0.7, cacheWrite: 0.8, total: 2.6 },
+		};
+		let observedToolUsage: Usage | undefined;
+		const echoTool: AgentTool = {
+			name: "echo",
+			label: "Echo",
+			description: "Echo text back",
+			parameters: Type.Object({ text: Type.String() }),
+			execute: async (_toolCallId, params) => {
+				const text = typeof params === "object" && params !== null && "text" in params ? String(params.text) : "";
+				return { content: [{ type: "text", text }], details: { text }, usage: toolUsage };
+			},
+		};
+		const harness = await createHarness({
+			tools: [echoTool],
+			extensionFactories: [
+				(pi) => {
+					pi.on("tool_result", async (event) => {
+						observedToolUsage = event.usage;
+						return {
+							content: [{ type: "text", text: "patched result" }],
+							details: { patched: true },
+							usage: patchedToolUsage,
+						};
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage([fauxToolCall("echo", { text: "hello" })], { stopReason: "toolUse" }),
+			(context) => {
+				const toolResult = context.messages.find((message) => message.role === "toolResult");
+				const text =
+					toolResult?.role === "toolResult"
+						? toolResult.content
+								.filter((part): part is { type: "text"; text: string } => part.type === "text")
+								.map((part) => part.text)
+								.join("\n")
+						: "";
+				return fauxAssistantMessage(text);
+			},
+		]);
+
+		await harness.session.prompt("hi");
+
+		expect(getAssistantTexts(harness)).toContain("patched result");
+		const toolResult = harness.session.messages.find(
+			(message) => message.role === "toolResult" && message.details?.patched === true,
+		);
+		expect(observedToolUsage).toEqual(toolUsage);
+		expect(toolResult).toBeDefined();
+		expect(toolResult?.role === "toolResult" ? toolResult.usage : undefined).toEqual(patchedToolUsage);
+	});
+
+	it("allows extension context handlers to modify messages before the LLM call", async () => {
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.on("context", async (event) => ({
+						messages: event.messages.map((message) =>
+							message.role === "user"
+								? { ...message, content: [{ type: "text", text: "rewritten" }], timestamp: message.timestamp }
+								: message,
+						),
+					}));
+				},
+			],
+		});
+		harnesses.push(harness);
+		let providerUserText = "";
+		harness.setResponses([
+			(context) => {
+				const user = context.messages.find((message) => message.role === "user");
+				providerUserText =
+					user && typeof user.content !== "string"
+						? user.content
+								.filter((part): part is { type: "text"; text: string } => part.type === "text")
+								.map((part) => part.text)
+								.join("\n")
+						: "";
+				return fauxAssistantMessage("done");
+			},
+		]);
+
+		await harness.session.prompt("original");
+
+		expect(providerUserText).toBe("rewritten");
+		const storedUserMessage = harness.session.messages.find((message) => message.role === "user");
+		expect(storedUserMessage?.role).toBe("user");
+		if (storedUserMessage?.role === "user") {
+			expect(storedUserMessage.content).toEqual([{ type: "text", text: "original" }]);
+		}
+	});
+
+	it("allows extension input handlers to transform or handle input", async () => {
+		let extensionApi: ExtensionAPI | undefined;
+		const transformedHarness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					extensionApi = pi;
+					pi.on("input", async (event) => {
+						if (event.text === "ping") {
+							return { action: "handled" };
+						}
+						return { action: "transform", text: `transformed:${event.text}` };
+					});
+				},
+			],
+		});
+		harnesses.push(transformedHarness);
+		let providerUserText = "";
+		transformedHarness.setResponses([
+			(context) => {
+				const user = context.messages.find((message) => message.role === "user");
+				providerUserText =
+					user && typeof user.content !== "string"
+						? user.content
+								.filter((part): part is { type: "text"; text: string } => part.type === "text")
+								.map((part) => part.text)
+								.join("\n")
+						: "";
+				return fauxAssistantMessage("done");
+			},
+		]);
+
+		await transformedHarness.session.prompt("hello");
+		await transformedHarness.session.prompt("ping");
+
+		expect(providerUserText).toBe("transformed:hello");
+		expect(transformedHarness.session.messages.filter((message) => message.role === "user")).toHaveLength(1);
+		expect(extensionApi).toBeDefined();
+	});
+
+	it("allows extension commands to inspect live system prompt options", async () => {
+		const seenOptions: BuildSystemPromptOptions[] = [];
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.registerCommand("inspect-options", {
+						description: "Inspect system prompt options",
+						handler: async (_args, ctx) => {
+							const options = ctx.getSystemPromptOptions();
+							seenOptions.push(options);
+							options.selectedTools?.push("mutated_tool");
+						},
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		await harness.session.prompt("/inspect-options");
+		await harness.session.prompt("/inspect-options");
+
+		expect(seenOptions).toHaveLength(2);
+		expect(seenOptions[0]).toBe(seenOptions[1]);
+		expect(seenOptions[0]?.cwd).toBe(harness.tempDir);
+		expect(seenOptions[0]?.selectedTools).toContain("read");
+		expect(seenOptions[1]?.selectedTools).toContain("mutated_tool");
+	});
+
+	it("allows before_agent_start handlers to inject custom messages and modify the system prompt", async () => {
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.on("before_agent_start", async (event) => ({
+						message: {
+							customType: "before-start",
+							content: "injected",
+							display: true,
+							details: { injected: true },
+						},
+						systemPrompt: `${event.systemPrompt}\n\nextra instructions`,
+					}));
+				},
+			],
+		});
+		harnesses.push(harness);
+		let providerSystemPrompt = "";
+		let sawInjectedUserMessage = false;
+		harness.setResponses([
+			(context) => {
+				providerSystemPrompt = context.systemPrompt ?? "";
+				sawInjectedUserMessage = context.messages.some(
+					(message) =>
+						message.role === "user" &&
+						typeof message.content !== "string" &&
+						message.content.some((part) => part.type === "text" && part.text === "injected"),
+				);
+				return fauxAssistantMessage("done");
+			},
+		]);
+
+		await harness.session.prompt("hello");
+
+		expect(providerSystemPrompt).toContain("extra instructions");
+		expect(sawInjectedUserMessage).toBe(true);
+		expect(
+			harness.session.messages.some((message) => message.role === "custom" && message.customType === "before-start"),
+		).toBe(true);
+	});
+
+	it("bindExtensions emits session_start and reload emits session_shutdown then session_start", async () => {
+		const lifecycleEvents: string[] = [];
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_start", async (event) => {
+						lifecycleEvents.push(`start:${event.reason}`);
+					});
+					pi.on("session_shutdown", async (event) => {
+						lifecycleEvents.push(`shutdown:${event.reason}`);
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		await harness.session.bindExtensions({ shutdownHandler: () => {} });
+		await harness.session.reload();
+
+		expect(lifecycleEvents).toEqual(["start:startup", "shutdown:reload", "start:reload"]);
+	});
+});

packages/coding-agent/test/suite/agent-session-prompt.test.ts

@@ -0,0 +1,506 @@
+import { mkdirSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import type { AgentTool } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall, type Model } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import type { ExtensionAPI, InputEvent } from "../../src/core/extensions/index.ts";
+import type { PromptTemplate } from "../../src/core/prompt-templates.ts";
+import { createSyntheticSourceInfo } from "../../src/core/source-info.ts";
+import { createTestResourceLoader } from "../utilities.ts";
+import { createHarness, getMessageText, type Harness } from "./harness.ts";
+
+describe("AgentSession prompt characterization", () => {
+	const harnesses: Harness[] = [];
+	const tempDirs: string[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+		while (tempDirs.length > 0) {
+			const tempDir = tempDirs.pop();
+			if (tempDir) {
+				rmSync(tempDir, { recursive: true, force: true });
+			}
+		}
+	});
+
+	it("prompts while idle and records a single text response", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+
+		harness.setResponses([fauxAssistantMessage("hello")]);
+
+		await harness.session.prompt("hi");
+
+		expect(harness.session.messages.map((message) => message.role)).toEqual(["user", "assistant"]);
+		expect(getMessageText(harness.session.messages[0]!)).toBe("hi");
+		expect(harness.getPendingResponseCount()).toBe(0);
+	});
+
+	it("handles a tool call turn and waits for the follow-up LLM response", async () => {
+		const toolRuns: string[] = [];
+		const echoTool: AgentTool = {
+			name: "echo",
+			label: "Echo",
+			description: "Echo text back",
+			parameters: Type.Object({ text: Type.String() }),
+			execute: async (_toolCallId, params) => {
+				const text = typeof params === "object" && params !== null && "text" in params ? String(params.text) : "";
+				toolRuns.push(text);
+				return {
+					content: [{ type: "text", text: `echo:${text}` }],
+					details: { text },
+				};
+			},
+		};
+		const harness = await createHarness({ tools: [echoTool] });
+		harnesses.push(harness);
+
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("echo", { text: "hello" }), { stopReason: "toolUse" }),
+			fauxAssistantMessage("done"),
+		]);
+
+		await harness.session.prompt("start");
+
+		expect(toolRuns).toEqual(["hello"]);
+		expect(harness.session.messages.map((message) => message.role)).toEqual([
+			"user",
+			"assistant",
+			"toolResult",
+			"assistant",
+		]);
+		expect(harness.session.messages[2]?.role).toBe("toolResult");
+		expect(harness.session.messages[3]?.role).toBe("assistant");
+	});
+
+	it("executes multiple tool calls from one response and continues with a single follow-up response", async () => {
+		const toolRuns: string[] = [];
+		const makeTool = (name: string, delayMs: number): AgentTool => ({
+			name,
+			label: name,
+			description: `${name} tool`,
+			parameters: Type.Object({ value: Type.String() }),
+			execute: async (_toolCallId, params) => {
+				const value =
+					typeof params === "object" && params !== null && "value" in params ? String(params.value) : "";
+				await new Promise((resolve) => setTimeout(resolve, delayMs));
+				toolRuns.push(`${name}:${value}`);
+				return {
+					content: [{ type: "text", text: `${name}:${value}` }],
+					details: { value },
+				};
+			},
+		});
+		const harness = await createHarness({ tools: [makeTool("slow", 25), makeTool("fast", 0)] });
+		harnesses.push(harness);
+
+		harness.setResponses([
+			fauxAssistantMessage([fauxToolCall("slow", { value: "a" }), fauxToolCall("fast", { value: "b" })], {
+				stopReason: "toolUse",
+			}),
+			(context) => {
+				const toolResults = context.messages.filter((message) => message.role === "toolResult");
+				return fauxAssistantMessage(`tool results: ${toolResults.length}`);
+			},
+		]);
+
+		await harness.session.prompt("run tools");
+
+		expect(toolRuns.sort()).toEqual(["fast:b", "slow:a"]);
+		expect(harness.session.messages.filter((message) => message.role === "toolResult")).toHaveLength(2);
+		expect(harness.session.messages[harness.session.messages.length - 1]?.role).toBe("assistant");
+	});
+
+	it("preserves image attachments in the provider context", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		let sawImage = false;
+
+		harness.setResponses([
+			(context) => {
+				const user = context.messages.find((message) => message.role === "user");
+				sawImage =
+					user?.role === "user" &&
+					typeof user.content !== "string" &&
+					user.content.some((part) => part.type === "image");
+				return fauxAssistantMessage("ok");
+			},
+		]);
+
+		await harness.session.prompt("describe", {
+			images: [
+				{
+					type: "image",
+					mimeType: "image/png",
+					data: "ZmFrZQ==",
+				},
+			],
+		});
+
+		expect(sawImage).toBe(true);
+	});
+
+	it("expands skill commands before sending the prompt", async () => {
+		const tempDir = join(tmpdir(), `pi-skill-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		mkdirSync(tempDir, { recursive: true });
+		tempDirs.push(tempDir);
+		const skillPath = join(tempDir, "test-skill.md");
+		writeFileSync(skillPath, "# Test Skill\n\nUse the skill body.");
+
+		const resourceLoader = {
+			...createTestResourceLoader(),
+			getSkills: () => ({
+				skills: [
+					{
+						name: "test",
+						description: "Test skill",
+						filePath: skillPath,
+						disableModelInvocation: false,
+						baseDir: tempDir,
+						sourceInfo: createSyntheticSourceInfo(skillPath, {
+							source: "local",
+							scope: "project",
+							origin: "top-level",
+							baseDir: tempDir,
+						}),
+					},
+				],
+				diagnostics: [],
+			}),
+		};
+		const harness = await createHarness({ resourceLoader });
+		harnesses.push(harness);
+		let expandedPrompt = "";
+
+		harness.setResponses([
+			(context) => {
+				const user = context.messages.find((message) => message.role === "user");
+				expandedPrompt = user ? getMessageText(user) : "";
+				return fauxAssistantMessage("ok");
+			},
+		]);
+
+		await harness.session.prompt("/skill:test explain this");
+
+		expect(expandedPrompt).toContain('<skill name="test" location="');
+		expect(expandedPrompt).toContain("Use the skill body.");
+		expect(expandedPrompt).toContain("explain this");
+	});
+
+	it("expands prompt templates before sending the prompt", async () => {
+		const template: PromptTemplate = {
+			name: "review",
+			description: "Review template",
+			content: "Review this code: $1",
+			filePath: "/virtual/review.md",
+			sourceInfo: createSyntheticSourceInfo("/virtual/review.md", {
+				source: "local",
+				scope: "temporary",
+				origin: "top-level",
+			}),
+		};
+		const resourceLoader = {
+			...createTestResourceLoader(),
+			getPrompts: () => ({ prompts: [template], diagnostics: [] }),
+		};
+		const harness = await createHarness({ resourceLoader });
+		harnesses.push(harness);
+		let expandedPrompt = "";
+
+		harness.setResponses([
+			(context) => {
+				const user = context.messages.find((message) => message.role === "user");
+				expandedPrompt = user ? getMessageText(user) : "";
+				return fauxAssistantMessage("ok");
+			},
+		]);
+
+		await harness.session.prompt("/review src/index.ts");
+
+		expect(expandedPrompt).toBe("Review this code: src/index.ts");
+	});
+
+	it("sendUserMessage can opt into prompt template expansion", async () => {
+		const template: PromptTemplate = {
+			name: "review",
+			description: "Review template",
+			content: "Review this code: $1",
+			filePath: "/virtual/review.md",
+			sourceInfo: createSyntheticSourceInfo("/virtual/review.md", {
+				source: "local",
+				scope: "temporary",
+				origin: "top-level",
+			}),
+		};
+		const resourceLoader = {
+			...createTestResourceLoader(),
+			getPrompts: () => ({ prompts: [template], diagnostics: [] }),
+		};
+		const harness = await createHarness({ resourceLoader });
+		harnesses.push(harness);
+		let expandedPrompt = "";
+
+		harness.setResponses([
+			(context) => {
+				const user = context.messages.find((message) => message.role === "user");
+				expandedPrompt = user ? getMessageText(user) : "";
+				return fauxAssistantMessage("ok");
+			},
+		]);
+
+		await harness.session.sendUserMessage("/review src/index.ts", { expandPromptTemplates: true });
+
+		expect(expandedPrompt).toBe("Review this code: src/index.ts");
+	});
+
+	it("dispatches extension commands without consuming a provider response", async () => {
+		const commandRuns: string[] = [];
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.registerCommand("testcmd", {
+						description: "Test command",
+						handler: async (args) => {
+							commandRuns.push(args);
+						},
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("should stay queued")]);
+
+		await harness.session.prompt("/testcmd hello world");
+
+		expect(commandRuns).toEqual(["hello world"]);
+		expect(harness.session.messages).toEqual([]);
+		expect(harness.getPendingResponseCount()).toBe(1);
+	});
+
+	it("extension sendUserMessage can opt into extension command dispatch", async () => {
+		let extensionApi: ExtensionAPI | undefined;
+		let resolveCommandRun: (args: string) => void = () => {};
+		const commandRun = new Promise<string>((resolve) => {
+			resolveCommandRun = resolve;
+		});
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					extensionApi = pi;
+					pi.registerCommand("testcmd", {
+						description: "Test command",
+						handler: async (args) => {
+							resolveCommandRun(args);
+						},
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		expect(extensionApi).toBeDefined();
+
+		extensionApi?.sendUserMessage("/testcmd hello world", { expandPromptTemplates: true });
+
+		await expect(commandRun).resolves.toBe("hello world");
+		expect(harness.session.messages).toEqual([]);
+		expect(harness.getPendingResponseCount()).toBe(0);
+	});
+
+	it("sendUserMessage while idle triggers a turn", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+
+		harness.setResponses([fauxAssistantMessage("response")]);
+
+		await harness.session.sendUserMessage("from extension");
+
+		expect(harness.session.messages.map((message) => message.role)).toEqual(["user", "assistant"]);
+		expect(getMessageText(harness.session.messages[0]!)).toBe("from extension");
+	});
+
+	it("does not report streamingBehavior to input handlers while idle", async () => {
+		const inputEvents: InputEvent[] = [];
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.on("input", (event) => {
+						inputEvents.push(event);
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("ok")]);
+
+		await harness.session.prompt("idle", { streamingBehavior: "followUp" });
+
+		expect(inputEvents).toHaveLength(1);
+		expect(inputEvents[0]?.streamingBehavior).toBeUndefined();
+	});
+
+	it("reports streamingBehavior to input handlers while streaming", async () => {
+		let releaseToolExecution: (() => void) | undefined;
+		const toolRelease = new Promise<void>((resolve) => {
+			releaseToolExecution = resolve;
+		});
+		const inputEvents: InputEvent[] = [];
+		const waitTool: AgentTool = {
+			name: "wait",
+			label: "Wait",
+			description: "Wait for release",
+			parameters: Type.Object({}),
+			execute: async () => {
+				await toolRelease;
+				return {
+					content: [{ type: "text", text: "released" }],
+					details: {},
+				};
+			},
+		};
+		const harness = await createHarness({
+			tools: [waitTool],
+			extensionFactories: [
+				(pi) => {
+					pi.on("input", (event) => {
+						inputEvents.push(event);
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("wait", {}), { stopReason: "toolUse" }),
+			fauxAssistantMessage("done"),
+		]);
+
+		const sawToolStart = new Promise<void>((resolve) => {
+			const unsubscribe = harness.session.subscribe((event) => {
+				if (event.type === "tool_execution_start") {
+					unsubscribe();
+					resolve();
+				}
+			});
+		});
+
+		const promptPromise = harness.session.prompt("start");
+		await sawToolStart;
+		await harness.session.prompt("queued", { streamingBehavior: "followUp" });
+
+		expect(inputEvents.map((event) => event.streamingBehavior)).toEqual([undefined, "followUp"]);
+
+		releaseToolExecution?.();
+		await promptPromise;
+	});
+
+	it("throws when prompted during streaming without a streamingBehavior", async () => {
+		let releaseToolExecution: (() => void) | undefined;
+		const toolRelease = new Promise<void>((resolve) => {
+			releaseToolExecution = resolve;
+		});
+		const waitTool: AgentTool = {
+			name: "wait",
+			label: "Wait",
+			description: "Wait for release",
+			parameters: Type.Object({}),
+			execute: async () => {
+				await toolRelease;
+				return {
+					content: [{ type: "text", text: "released" }],
+					details: {},
+				};
+			},
+		};
+		const harness = await createHarness({ tools: [waitTool] });
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("wait", {}), { stopReason: "toolUse" }),
+			fauxAssistantMessage("done"),
+		]);
+
+		const sawToolStart = new Promise<void>((resolve) => {
+			const unsubscribe = harness.session.subscribe((event) => {
+				if (event.type === "tool_execution_start") {
+					unsubscribe();
+					resolve();
+				}
+			});
+		});
+
+		const promptPromise = harness.session.prompt("start");
+		await sawToolStart;
+
+		await expect(harness.session.prompt("second")).rejects.toThrow(
+			"Agent is already processing. Specify streamingBehavior ('steer' or 'followUp') to queue the message.",
+		);
+
+		releaseToolExecution?.();
+		await promptPromise;
+	});
+
+	it("throws when prompted during manual compaction", async () => {
+		let markCompactionStarted = () => {};
+		const compactionStarted = new Promise<void>((resolve) => {
+			markCompactionStarted = resolve;
+		});
+		let releaseCompaction = () => {};
+		const compactionReleased = new Promise<void>((resolve) => {
+			releaseCompaction = resolve;
+		});
+		const harness = await createHarness({
+			settings: { compaction: { keepRecentTokens: 1 } },
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_compact", async (event) => {
+						markCompactionStarted();
+						await compactionReleased;
+						return {
+							compaction: {
+								summary: "manual compacted",
+								firstKeptEntryId: event.preparation.firstKeptEntryId,
+								tokensBefore: event.preparation.tokensBefore,
+								details: {},
+							},
+						};
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("one"), fauxAssistantMessage("two")]);
+		await harness.session.prompt("first");
+		await harness.session.prompt("second");
+
+		const compactPromise = harness.session.compact();
+		await compactionStarted;
+
+		try {
+			await expect(harness.session.prompt("third")).rejects.toThrow(
+				"Cannot submit a prompt while compaction is in progress. Wait for compaction to finish and retry.",
+			);
+		} finally {
+			releaseCompaction();
+			await compactPromise;
+		}
+	});
+
+	it("throws when prompting without a model", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		harness.session.agent.state.model = undefined as unknown as Model<any>;
+
+		await expect(harness.session.prompt("hi")).rejects.toThrow("No model selected.");
+	});
+
+	it("throws when prompting without configured auth", async () => {
+		const harness = await createHarness({ withConfiguredAuth: false });
+		harnesses.push(harness);
+
+		await expect(harness.session.prompt("hi")).rejects.toThrow(
+			`No API key found for ${harness.getModel().provider}.`,
+		);
+	});
+});

packages/coding-agent/test/suite/agent-session-queue.test.ts

@@ -0,0 +1,445 @@
+import type { AgentTool } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, getAssistantTexts, getMessageText, getUserTexts, type Harness } from "./harness.ts";
+
+async function createWaitingHarness(
+	options: {
+		tools?: AgentTool[];
+		extensionFactories?: Harness["session"]["extensionRunner"] extends never
+			? never
+			: Array<(pi: ExtensionAPI) => void>;
+	} = {},
+): Promise<{
+	harness: Harness;
+	releaseToolExecution: () => void;
+	promptPromise: Promise<void>;
+	waitForToolStart: Promise<void>;
+}> {
+	let releaseToolExecution: (() => void) | undefined;
+	const toolRelease = new Promise<void>((resolve) => {
+		releaseToolExecution = resolve;
+	});
+	const waitTool: AgentTool = {
+		name: "wait",
+		label: "Wait",
+		description: "Wait for release",
+		parameters: Type.Object({}),
+		execute: async () => {
+			await toolRelease;
+			return {
+				content: [{ type: "text", text: "released" }],
+				details: {},
+			};
+		},
+	};
+	const harness = await createHarness({
+		tools: [waitTool, ...(options.tools ?? [])],
+		extensionFactories: options.extensionFactories,
+	});
+
+	const waitForToolStart = new Promise<void>((resolve) => {
+		const unsubscribe = harness.session.subscribe((event) => {
+			if (event.type === "tool_execution_start" && event.toolName === "wait") {
+				unsubscribe();
+				resolve();
+			}
+		});
+	});
+
+	return {
+		harness,
+		releaseToolExecution: () => releaseToolExecution?.(),
+		promptPromise: harness.session.prompt("start"),
+		waitForToolStart,
+	};
+}
+
+describe("AgentSession queue characterization", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("dispatches extension commands immediately when prompted while idle", async () => {
+		const commandRuns: string[] = [];
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.registerCommand("testcmd", {
+						description: "Test command",
+						handler: async (args) => {
+							commandRuns.push(args);
+						},
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		await harness.session.prompt("/testcmd hello world");
+
+		expect(commandRuns).toEqual(["hello world"]);
+		expect(harness.getPendingResponseCount()).toBe(0);
+		expect(harness.session.messages).toEqual([]);
+	});
+
+	it("delivers extension-origin steering messages before the next LLM call", async () => {
+		let extensionApi: ExtensionAPI | undefined;
+		const waiting = await createWaitingHarness({
+			extensionFactories: [
+				(pi) => {
+					extensionApi = pi;
+				},
+			],
+		});
+		const { harness, waitForToolStart, promptPromise, releaseToolExecution } = waiting;
+		harnesses.push(harness);
+
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("wait", {}), { stopReason: "toolUse" }),
+			(context) => {
+				const sawSteer = context.messages.some(
+					(message) => message.role === "user" && getMessageText(message) === "steer now",
+				);
+				return fauxAssistantMessage(sawSteer ? "saw steer" : "missing steer");
+			},
+		]);
+
+		await waitForToolStart;
+		await new Promise((resolve) => setTimeout(resolve, 0));
+
+		extensionApi?.sendUserMessage("steer now", { deliverAs: "steer" });
+		releaseToolExecution();
+		await promptPromise;
+
+		expect(getUserTexts(harness)).toEqual(["start", "steer now"]);
+		expect(getAssistantTexts(harness)).toContain("saw steer");
+	});
+
+	it("delivers follow-up messages only after the current run finishes", async () => {
+		const waiting = await createWaitingHarness();
+		const { harness, waitForToolStart, promptPromise, releaseToolExecution } = waiting;
+		harnesses.push(harness);
+		const assistantSeenBeforeFollowUp: string[] = [];
+
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("wait", {}), { stopReason: "toolUse" }),
+			(context) => {
+				assistantSeenBeforeFollowUp.push(
+					...context.messages
+						.filter((message) => message.role === "assistant")
+						.map((message) =>
+							message.content
+								.filter((part): part is { type: "text"; text: string } => part.type === "text")
+								.map((part) => part.text)
+								.join("\n"),
+						),
+				);
+				return fauxAssistantMessage("follow-up response");
+			},
+		]);
+
+		await waitForToolStart;
+		await harness.session.followUp("after current run");
+		releaseToolExecution();
+		await promptPromise;
+
+		expect(getUserTexts(harness)).toEqual(["start", "after current run"]);
+		expect(assistantSeenBeforeFollowUp).toContain("");
+		expect(getAssistantTexts(harness)).toContain("follow-up response");
+	});
+
+	it("delivers multiple steering messages in order in one-at-a-time mode", async () => {
+		const waiting = await createWaitingHarness();
+		const { harness, waitForToolStart, promptPromise, releaseToolExecution } = waiting;
+		harnesses.push(harness);
+
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("wait", {}), { stopReason: "toolUse" }),
+			fauxAssistantMessage("handled steer 1"),
+			fauxAssistantMessage("handled steer 2"),
+		]);
+
+		await waitForToolStart;
+		await harness.session.steer("steer 1");
+		await harness.session.steer("steer 2");
+		releaseToolExecution();
+		await promptPromise;
+
+		expect(getUserTexts(harness)).toEqual(["start", "steer 1", "steer 2"]);
+		expect(getAssistantTexts(harness)).toEqual(["", "handled steer 1", "handled steer 2"]);
+	});
+
+	it("delivers multiple follow-up messages in order in one-at-a-time mode", async () => {
+		const waiting = await createWaitingHarness();
+		const { harness, waitForToolStart, promptPromise, releaseToolExecution } = waiting;
+		harnesses.push(harness);
+
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("wait", {}), { stopReason: "toolUse" }),
+			fauxAssistantMessage("original turn complete"),
+			fauxAssistantMessage("handled follow-up 1"),
+			fauxAssistantMessage("handled follow-up 2"),
+		]);
+
+		await waitForToolStart;
+		await harness.session.followUp("follow-up 1");
+		await harness.session.followUp("follow-up 2");
+		releaseToolExecution();
+		await promptPromise;
+
+		expect(getUserTexts(harness)).toEqual(["start", "follow-up 1", "follow-up 2"]);
+		expect(getAssistantTexts(harness)).toEqual([
+			"",
+			"original turn complete",
+			"handled follow-up 1",
+			"handled follow-up 2",
+		]);
+	});
+
+	it("delivers all steering messages in one batch in all mode", async () => {
+		const waiting = await createWaitingHarness();
+		const { harness, waitForToolStart, promptPromise, releaseToolExecution } = waiting;
+		harnesses.push(harness);
+		harness.session.setSteeringMode("all");
+		let batchedUserMessages: string[] = [];
+
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("wait", {}), { stopReason: "toolUse" }),
+			(context) => {
+				batchedUserMessages = context.messages
+					.filter((message) => message.role === "user")
+					.map((message) => getMessageText(message));
+				return fauxAssistantMessage("batched steer response");
+			},
+		]);
+
+		await waitForToolStart;
+		await harness.session.steer("steer 1");
+		await harness.session.steer("steer 2");
+		releaseToolExecution();
+		await promptPromise;
+
+		expect(batchedUserMessages).toEqual(["start", "steer 1", "steer 2"]);
+		expect(getAssistantTexts(harness)).toEqual(["", "batched steer response"]);
+	});
+
+	it("delivers all follow-up messages in one batch in all mode", async () => {
+		const waiting = await createWaitingHarness();
+		const { harness, waitForToolStart, promptPromise, releaseToolExecution } = waiting;
+		harnesses.push(harness);
+		harness.session.setFollowUpMode("all");
+		let batchedUserMessages: string[] = [];
+
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("wait", {}), { stopReason: "toolUse" }),
+			fauxAssistantMessage("original turn complete"),
+			(context) => {
+				batchedUserMessages = context.messages
+					.filter((message) => message.role === "user")
+					.map((message) => getMessageText(message));
+				return fauxAssistantMessage("batched follow-up response");
+			},
+		]);
+
+		await waitForToolStart;
+		await harness.session.followUp("follow-up 1");
+		await harness.session.followUp("follow-up 2");
+		releaseToolExecution();
+		await promptPromise;
+
+		expect(batchedUserMessages).toEqual(["start", "follow-up 1", "follow-up 2"]);
+		expect(getAssistantTexts(harness)).toEqual(["", "original turn complete", "batched follow-up response"]);
+	});
+
+	it("queues custom messages with deliverAs steer while streaming", async () => {
+		const waiting = await createWaitingHarness();
+		const { harness, waitForToolStart, promptPromise, releaseToolExecution } = waiting;
+		harnesses.push(harness);
+		let sawCustomMessage = false;
+
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("wait", {}), { stopReason: "toolUse" }),
+			(context) => {
+				sawCustomMessage = context.messages.some(
+					(message) =>
+						message.role === "user" &&
+						typeof message.content !== "string" &&
+						message.content.some((part) => part.type === "text" && part.text === "steer custom"),
+				);
+				return fauxAssistantMessage("done");
+			},
+		]);
+
+		await waitForToolStart;
+		await harness.session.sendCustomMessage(
+			{ customType: "queue-test", content: "steer custom", display: true, details: { value: 1 } },
+			{ deliverAs: "steer" },
+		);
+		releaseToolExecution();
+		await promptPromise;
+
+		expect(sawCustomMessage).toBe(true);
+		expect(
+			harness.session.messages.some((message) => message.role === "custom" && message.customType === "queue-test"),
+		).toBe(true);
+	});
+
+	it("queues custom messages with deliverAs followUp while streaming", async () => {
+		const waiting = await createWaitingHarness();
+		const { harness, waitForToolStart, promptPromise, releaseToolExecution } = waiting;
+		harnesses.push(harness);
+		let sawCustomMessage = false;
+
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("wait", {}), { stopReason: "toolUse" }),
+			fauxAssistantMessage("original turn complete"),
+			(context) => {
+				sawCustomMessage = context.messages.some(
+					(message) =>
+						message.role === "user" &&
+						typeof message.content !== "string" &&
+						message.content.some((part) => part.type === "text" && part.text === "follow-up custom"),
+				);
+				return fauxAssistantMessage("done");
+			},
+		]);
+
+		await waitForToolStart;
+		await harness.session.sendCustomMessage(
+			{ customType: "queue-test", content: "follow-up custom", display: true, details: { value: 1 } },
+			{ deliverAs: "followUp" },
+		);
+		releaseToolExecution();
+		await promptPromise;
+
+		expect(sawCustomMessage).toBe(true);
+		expect(
+			harness.session.messages.some((message) => message.role === "custom" && message.customType === "queue-test"),
+		).toBe(true);
+	});
+
+	it("injects nextTurn custom messages into the next prompt", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		let sawCustomMessage = false;
+
+		await harness.session.sendCustomMessage(
+			{ customType: "next-turn", content: "carry this", display: true, details: {} },
+			{ deliverAs: "nextTurn" },
+		);
+
+		harness.setResponses([
+			(context) => {
+				sawCustomMessage = context.messages.some(
+					(message) =>
+						message.role === "user" &&
+						typeof message.content !== "string" &&
+						message.content.some((part) => part.type === "text" && part.text === "carry this"),
+				);
+				return fauxAssistantMessage("done");
+			},
+		]);
+
+		await harness.session.prompt("normal prompt");
+
+		expect(sawCustomMessage).toBe(true);
+		expect(harness.session.messages.map((message) => message.role)).toEqual(["user", "custom", "assistant"]);
+	});
+
+	it("updates pendingMessageCount and removes queued text before message_start is emitted", async () => {
+		const waiting = await createWaitingHarness();
+		const { harness, waitForToolStart, promptPromise, releaseToolExecution } = waiting;
+		harnesses.push(harness);
+		const countsAtQueuedMessageStart: number[] = [];
+
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("wait", {}), { stopReason: "toolUse" }),
+			fauxAssistantMessage("done"),
+		]);
+
+		harness.session.subscribe((event) => {
+			if (
+				event.type === "message_start" &&
+				event.message.role === "user" &&
+				getMessageText(event.message) === "queued"
+			) {
+				countsAtQueuedMessageStart.push(harness.session.pendingMessageCount);
+			}
+		});
+
+		await waitForToolStart;
+		await harness.session.steer("queued");
+		expect(harness.session.pendingMessageCount).toBe(1);
+		releaseToolExecution();
+		await promptPromise;
+
+		expect(countsAtQueuedMessageStart).toEqual([0]);
+		expect(harness.session.pendingMessageCount).toBe(0);
+	});
+
+	it("throws when queueing an extension command with steer", async () => {
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.registerCommand("testcmd", {
+						description: "Test command",
+						handler: async () => {},
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		await expect(harness.session.steer("/testcmd queued")).rejects.toThrow(
+			'Extension command "/testcmd" cannot be queued. Use prompt() or execute the command when not streaming.',
+		);
+	});
+
+	it("throws when queueing an extension command with followUp", async () => {
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.registerCommand("testcmd", {
+						description: "Test command",
+						handler: async () => {},
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		await expect(harness.session.followUp("/testcmd queued")).rejects.toThrow(
+			'Extension command "/testcmd" cannot be queued. Use prompt() or execute the command when not streaming.',
+		);
+	});
+
+	it("delivers follow-ups queued during agent_end", async () => {
+		let sent = false;
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi: ExtensionAPI) => {
+					pi.on("agent_end", async () => {
+						if (sent) return;
+						sent = true;
+						pi.sendUserMessage("conflict report", { deliverAs: "followUp" });
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		harness.setResponses([fauxAssistantMessage("reply"), fauxAssistantMessage("follow-up reply")]);
+
+		await harness.session.prompt("hello");
+		await harness.session.agent.waitForIdle();
+
+		expect(getUserTexts(harness)).toEqual(["hello", "conflict report"]);
+	});
+});

packages/coding-agent/test/suite/agent-session-retry-events.test.ts

@@ -0,0 +1,364 @@
+import type { AgentTool } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxThinking, fauxToolCall } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, type Harness } from "./harness.ts";
+
+function normalizeEventOrder(events: Harness["events"]): string[] {
+	const normalized: string[] = [];
+	for (const event of events) {
+		const label =
+			event.type === "message_start" || event.type === "message_end"
+				? `${event.type}:${event.message.role}`
+				: event.type === "tool_execution_start" || event.type === "tool_execution_end"
+					? `${event.type}:${event.toolName}`
+					: event.type;
+		if (label === "message_update" && normalized[normalized.length - 1] === "message_update") {
+			continue;
+		}
+		normalized.push(label);
+	}
+	return normalized;
+}
+
+describe("AgentSession retry and event characterization", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("retries after a transient error and succeeds", async () => {
+		const harness = await createHarness({ settings: { retry: { enabled: true, maxRetries: 3, baseDelayMs: 1 } } });
+		harnesses.push(harness);
+		const retryEvents: string[] = [];
+		harness.session.subscribe((event) => {
+			if (event.type === "auto_retry_start") retryEvents.push(`start:${event.attempt}`);
+			if (event.type === "auto_retry_end") retryEvents.push(`end:${event.success}`);
+		});
+
+		harness.setResponses([
+			fauxAssistantMessage("", { stopReason: "error", errorMessage: "overloaded_error" }),
+			fauxAssistantMessage("recovered"),
+		]);
+
+		await harness.session.prompt("test");
+
+		expect(retryEvents).toEqual(["start:1", "end:true"]);
+		expect(harness.eventsOfType("agent_end").map((event) => event.willRetry)).toEqual([true, false]);
+		expect(harness.faux.state.callCount).toBe(2);
+		expect(harness.session.isRetrying).toBe(false);
+	});
+
+	it("retries multiple transient failures and succeeds on the final attempt", async () => {
+		const harness = await createHarness({ settings: { retry: { enabled: true, maxRetries: 3, baseDelayMs: 1 } } });
+		harnesses.push(harness);
+		const retryEvents: string[] = [];
+		harness.session.subscribe((event) => {
+			if (event.type === "auto_retry_start") retryEvents.push(`start:${event.attempt}`);
+			if (event.type === "auto_retry_end") retryEvents.push(`end:${event.success}`);
+		});
+
+		harness.setResponses([
+			fauxAssistantMessage("", { stopReason: "error", errorMessage: "overloaded_error" }),
+			fauxAssistantMessage("", { stopReason: "error", errorMessage: "overloaded_error" }),
+			fauxAssistantMessage("success"),
+		]);
+
+		await harness.session.prompt("test");
+
+		expect(retryEvents).toEqual(["start:1", "start:2", "end:true"]);
+		expect(harness.faux.state.callCount).toBe(3);
+	});
+
+	it("exhausts max retries and emits a failure event", async () => {
+		const harness = await createHarness({ settings: { retry: { enabled: true, maxRetries: 2, baseDelayMs: 1 } } });
+		harnesses.push(harness);
+		const retryEvents: string[] = [];
+		harness.session.subscribe((event) => {
+			if (event.type === "auto_retry_start") retryEvents.push(`start:${event.attempt}`);
+			if (event.type === "auto_retry_end") retryEvents.push(`end:${event.success}`);
+		});
+
+		harness.setResponses([
+			fauxAssistantMessage("", { stopReason: "error", errorMessage: "overloaded_error" }),
+			fauxAssistantMessage("", { stopReason: "error", errorMessage: "overloaded_error" }),
+			fauxAssistantMessage("", { stopReason: "error", errorMessage: "overloaded_error" }),
+		]);
+
+		await harness.session.prompt("test");
+
+		expect(retryEvents).toEqual(["start:1", "start:2", "end:false"]);
+		expect(harness.eventsOfType("agent_end").map((event) => event.willRetry)).toEqual([true, true, false]);
+		expect(harness.faux.state.callCount).toBe(3);
+		expect(harness.session.isRetrying).toBe(false);
+	});
+
+	it("prompt waits for retry completion even when assistant message_end handling is delayed", async () => {
+		const harness = await createHarness({
+			settings: { retry: { enabled: true, maxRetries: 3, baseDelayMs: 1 } },
+			extensionFactories: [
+				(pi) => {
+					pi.on("message_end", async (event) => {
+						if (event.message.role === "assistant") {
+							await new Promise((resolve) => setTimeout(resolve, 40));
+						}
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage("", { stopReason: "error", errorMessage: "overloaded_error" }),
+			fauxAssistantMessage("recovered"),
+		]);
+
+		await harness.session.prompt("test");
+
+		expect(harness.faux.state.callCount).toBe(2);
+		expect(harness.session.isRetrying).toBe(false);
+	});
+
+	it("does not retry when retry is disabled", async () => {
+		const harness = await createHarness({ settings: { retry: { enabled: false } } });
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("", { stopReason: "error", errorMessage: "overloaded_error" })]);
+
+		await harness.session.prompt("test");
+
+		expect(harness.faux.state.callCount).toBe(1);
+		expect(harness.eventsOfType("auto_retry_start")).toEqual([]);
+	});
+
+	it("does not retry non-retryable errors", async () => {
+		const harness = await createHarness({ settings: { retry: { enabled: true, maxRetries: 3, baseDelayMs: 1 } } });
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("", { stopReason: "error", errorMessage: "invalid_api_key" })]);
+
+		await harness.session.prompt("test");
+
+		expect(harness.faux.state.callCount).toBe(1);
+		expect(harness.eventsOfType("auto_retry_start")).toEqual([]);
+	});
+
+	it("cancels retry sleep when abortRetry is called", async () => {
+		const harness = await createHarness({ settings: { retry: { enabled: true, maxRetries: 3, baseDelayMs: 100 } } });
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("", { stopReason: "error", errorMessage: "overloaded_error" })]);
+
+		const sawRetryStart = new Promise<void>((resolve) => {
+			const unsubscribe = harness.session.subscribe((event) => {
+				if (event.type === "auto_retry_start") {
+					unsubscribe();
+					resolve();
+				}
+			});
+		});
+
+		const promptPromise = harness.session.prompt("test");
+		await sawRetryStart;
+		harness.session.abortRetry();
+		await promptPromise;
+
+		expect(harness.session.isRetrying).toBe(false);
+		expect(harness.eventsOfType("auto_retry_end").map((event) => event.finalError)).toContain("Retry cancelled");
+		expect(harness.faux.state.callCount).toBe(1);
+	});
+
+	it("waits for the full loop when retry recovery produces tool calls", async () => {
+		const toolRuns: string[] = [];
+		const echoTool: AgentTool = {
+			name: "echo",
+			label: "Echo",
+			description: "Echo text back",
+			parameters: Type.Object({ text: Type.String() }),
+			execute: async (_toolCallId, params) => {
+				const text = typeof params === "object" && params !== null && "text" in params ? String(params.text) : "";
+				toolRuns.push(text);
+				return { content: [{ type: "text", text: `echo:${text}` }], details: { text } };
+			},
+		};
+		const harness = await createHarness({
+			tools: [echoTool],
+			settings: { retry: { enabled: true, maxRetries: 3, baseDelayMs: 1 } },
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage("", { stopReason: "error", errorMessage: "overloaded_error" }),
+			fauxAssistantMessage([fauxToolCall("echo", { text: "hello" })], { stopReason: "toolUse" }),
+			fauxAssistantMessage("final answer"),
+		]);
+
+		await harness.session.prompt("test");
+
+		expect(harness.faux.state.callCount).toBe(3);
+		expect(toolRuns).toEqual(["hello"]);
+		expect(harness.session.isStreaming).toBe(false);
+		await harness.session.prompt("follow-up");
+		expect(harness.faux.state.callCount).toBe(4);
+	});
+
+	it("emits extension events before public event subscribers", async () => {
+		const order: string[] = [];
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.on("message_start", async (event) => {
+						order.push(`extension:${event.type}:${event.message.role}`);
+					});
+					pi.on("message_end", async (event) => {
+						order.push(`extension:${event.type}:${event.message.role}`);
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.session.subscribe((event) => {
+			if (event.type === "message_start" || event.type === "message_end") {
+				order.push(`public:${event.type}:${event.message.role}`);
+			}
+		});
+		harness.setResponses([fauxAssistantMessage("done")]);
+
+		await harness.session.prompt("hi");
+
+		expect(order).toEqual([
+			"extension:message_start:user",
+			"public:message_start:user",
+			"extension:message_end:user",
+			"public:message_end:user",
+			"extension:message_start:assistant",
+			"public:message_start:assistant",
+			"extension:message_end:assistant",
+			"public:message_end:assistant",
+		]);
+	});
+
+	it("emits the expected event order for a single prompt", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("hello")]);
+
+		await harness.session.prompt("hi");
+
+		expect(normalizeEventOrder(harness.events)).toEqual([
+			"agent_start",
+			"turn_start",
+			"message_start:user",
+			"message_end:user",
+			"message_start:assistant",
+			"message_update",
+			"message_end:assistant",
+			"turn_end",
+			"agent_end",
+			"agent_settled",
+		]);
+	});
+
+	it("emits the expected event order for a tool call turn", async () => {
+		const toolRuns: string[] = [];
+		const echoTool: AgentTool = {
+			name: "echo",
+			label: "Echo",
+			description: "Echo text back",
+			parameters: Type.Object({ text: Type.String() }),
+			execute: async (_toolCallId, params) => {
+				const text = typeof params === "object" && params !== null && "text" in params ? String(params.text) : "";
+				toolRuns.push(text);
+				return { content: [{ type: "text", text: `echo:${text}` }], details: { text } };
+			},
+		};
+		const harness = await createHarness({ tools: [echoTool] });
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage([fauxToolCall("echo", { text: "hello" })], { stopReason: "toolUse" }),
+			fauxAssistantMessage("done"),
+		]);
+
+		await harness.session.prompt("hi");
+
+		expect(toolRuns).toEqual(["hello"]);
+		expect(normalizeEventOrder(harness.events)).toEqual([
+			"agent_start",
+			"turn_start",
+			"message_start:user",
+			"message_end:user",
+			"message_start:assistant",
+			"message_update",
+			"message_end:assistant",
+			"tool_execution_start:echo",
+			"tool_execution_end:echo",
+			"message_start:toolResult",
+			"message_end:toolResult",
+			"turn_end",
+			"turn_start",
+			"message_start:assistant",
+			"message_update",
+			"message_end:assistant",
+			"turn_end",
+			"agent_end",
+			"agent_settled",
+		]);
+	});
+
+	it("emits streaming deltas for text, thinking, and tool calls in message_update events", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage(
+				[fauxThinking("plan"), { type: "text", text: "answer" }, fauxToolCall("echo", { text: "hello" })],
+				{
+					stopReason: "toolUse",
+				},
+			),
+		]);
+
+		await harness.session.prompt("hi").catch(() => {});
+
+		const updateTypes = harness.eventsOfType("message_update").map((event) => event.assistantMessageEvent.type);
+		expect(updateTypes).toContain("thinking_delta");
+		expect(updateTypes).toContain("text_delta");
+		expect(updateTypes).toContain("toolcall_delta");
+	});
+
+	it("emits agent_end for error responses", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("", { stopReason: "error", errorMessage: "broken" })]);
+
+		await harness.session.prompt("hi");
+
+		expect(harness.eventsOfType("agent_end")).toHaveLength(1);
+		expect(harness.events[harness.events.length - 1]?.type).toBe("agent_settled");
+	});
+
+	it("emits agent_end for aborted runs and persists the aborted assistant message", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("x".repeat(20_000))]);
+
+		const sawMessageUpdate = new Promise<void>((resolve) => {
+			const unsubscribe = harness.session.subscribe((event) => {
+				if (event.type === "message_update") {
+					unsubscribe();
+					resolve();
+				}
+			});
+		});
+
+		const promptPromise = harness.session.prompt("hi");
+		await sawMessageUpdate;
+		await harness.session.abort();
+		await promptPromise;
+
+		expect(harness.eventsOfType("agent_end")).toHaveLength(1);
+		expect(harness.events[harness.events.length - 1]?.type).toBe("agent_settled");
+		const lastMessage = harness.session.messages[harness.session.messages.length - 1];
+		expect(lastMessage?.role).toBe("assistant");
+		if (lastMessage?.role === "assistant") {
+			expect(lastMessage.stopReason).toBe("aborted");
+		}
+	});
+});

packages/coding-agent/test/suite/agent-session-runtime.test.ts

@@ -0,0 +1,693 @@
+import { existsSync, mkdirSync, readFileSync, realpathSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join, parse } from "node:path";
+import { fauxAssistantMessage, fauxToolCall, registerFauxProvider } from "@earendil-works/pi-ai/compat";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import {
+	type CreateAgentSessionRuntimeFactory,
+	createAgentSessionFromServices,
+	createAgentSessionRuntime,
+	createAgentSessionServices,
+} from "../../src/core/agent-session-runtime.ts";
+import { AuthStorage } from "../../src/core/auth-storage.ts";
+import { SessionManager } from "../../src/core/session-manager.ts";
+import type {
+	AgentToolResult,
+	ExtensionAPI,
+	ExtensionFactory,
+	SessionBeforeForkEvent,
+	SessionBeforeSwitchEvent,
+	SessionShutdownEvent,
+	SessionStartEvent,
+} from "../../src/index.ts";
+
+type RecordedSessionEvent =
+	| SessionBeforeSwitchEvent
+	| SessionBeforeForkEvent
+	| SessionShutdownEvent
+	| SessionStartEvent;
+
+describe("AgentSessionRuntime characterization", () => {
+	const cleanups: Array<() => Promise<void> | void> = [];
+
+	afterEach(async () => {
+		while (cleanups.length > 0) {
+			await cleanups.pop()?.();
+		}
+	});
+
+	async function createRuntimeForTest(
+		extensionFactory: ExtensionFactory,
+		options?: { cwd?: string; bootstrapModel?: boolean; bootstrapThinkingLevel?: boolean },
+	) {
+		const tempDir =
+			options?.cwd ?? join(tmpdir(), `pi-runtime-suite-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		mkdirSync(tempDir, { recursive: true });
+
+		const faux = registerFauxProvider({
+			models: [
+				{ id: "faux-1", reasoning: true },
+				{ id: "faux-2", reasoning: false },
+			],
+		});
+		faux.setResponses([fauxAssistantMessage("one"), fauxAssistantMessage("two"), fauxAssistantMessage("three")]);
+
+		const authStorage = AuthStorage.inMemory();
+		await authStorage.modify(faux.getModel().provider, async () => ({ type: "api_key", key: "faux-key" }));
+
+		const runtimeOptions = {
+			agentDir: tempDir,
+			authStorage,
+			model: options?.bootstrapModel === false ? undefined : faux.getModel(),
+			thinkingLevel: options?.bootstrapThinkingLevel === false ? undefined : undefined,
+			resourceLoaderOptions: {
+				extensionFactories: [
+					(pi: ExtensionAPI) => {
+						pi.registerProvider(faux.getModel().provider, {
+							baseUrl: faux.getModel().baseUrl,
+							apiKey: "faux-key",
+							api: faux.api,
+							models: faux.models.map((registeredModel) => ({
+								id: registeredModel.id,
+								name: registeredModel.name,
+								api: registeredModel.api,
+								reasoning: registeredModel.reasoning,
+								input: registeredModel.input,
+								cost: registeredModel.cost,
+								contextWindow: registeredModel.contextWindow,
+								maxTokens: registeredModel.maxTokens,
+							})),
+						});
+						extensionFactory(pi);
+					},
+				],
+				noSkills: true,
+				noPromptTemplates: true,
+				noThemes: true,
+			},
+		};
+		const createRuntime: CreateAgentSessionRuntimeFactory = async ({ cwd, sessionManager, sessionStartEvent }) => {
+			const services = await createAgentSessionServices({
+				...runtimeOptions,
+				cwd,
+			});
+			return {
+				...(await createAgentSessionFromServices({
+					services,
+					sessionManager,
+					sessionStartEvent,
+					model: runtimeOptions.model,
+					thinkingLevel: runtimeOptions.thinkingLevel,
+				})),
+				services,
+				diagnostics: services.diagnostics,
+			};
+		};
+		const runtime = await createAgentSessionRuntime(createRuntime, {
+			cwd: tempDir,
+			agentDir: tempDir,
+			sessionManager: SessionManager.create(tempDir),
+		});
+		await runtime.session.bindExtensions({});
+
+		cleanups.push(async () => {
+			await runtime.dispose();
+			faux.unregister();
+			if (existsSync(tempDir)) {
+				rmSync(tempDir, { recursive: true, force: true });
+			}
+		});
+
+		return { runtime, faux, tempDir };
+	}
+
+	it("persists message_end assistant replacements to the session manager", async () => {
+		const { runtime } = await createRuntimeForTest((pi: ExtensionAPI) => {
+			pi.on("message_end", (event) => {
+				if (event.message.role !== "assistant") return;
+
+				return {
+					message: {
+						...event.message,
+						usage: {
+							...event.message.usage,
+							cost: {
+								...event.message.usage.cost,
+								total: 0.123,
+							},
+						},
+					},
+				};
+			});
+		});
+
+		await runtime.session.prompt("hello");
+
+		const sessionAssistant = runtime.session.messages.find((message) => message.role === "assistant");
+		expect(sessionAssistant?.role).toBe("assistant");
+		if (sessionAssistant?.role !== "assistant") {
+			throw new Error("missing assistant message");
+		}
+		expect(sessionAssistant.usage.cost.total).toBe(0.123);
+
+		const persistedAssistant = runtime.session.sessionManager
+			.getEntries()
+			.filter((entry) => entry.type === "message")
+			.map((entry) => entry.message)
+			.find((message) => message.role === "assistant");
+		expect(persistedAssistant?.role).toBe("assistant");
+		if (persistedAssistant?.role !== "assistant") {
+			throw new Error("missing persisted assistant message");
+		}
+		expect(persistedAssistant.usage.cost.total).toBe(0.123);
+	});
+
+	it("settles the active response before session replacement", async () => {
+		let toolStarted!: () => void;
+		const toolStartedPromise = new Promise<void>((resolve) => {
+			toolStarted = resolve;
+		});
+		const { runtime, faux } = await createRuntimeForTest((pi: ExtensionAPI) => {
+			pi.registerTool({
+				name: "block",
+				label: "Block",
+				description: "Blocks until aborted",
+				parameters: Type.Object({}),
+				execute: (_toolCallId, _params, signal) =>
+					new Promise<AgentToolResult<unknown>>((resolve) => {
+						toolStarted();
+						signal?.addEventListener("abort", () =>
+							resolve({ content: [{ type: "text", text: "tool aborted" }], details: {} }),
+						);
+					}),
+			});
+		});
+
+		await runtime.session.prompt("hello");
+		const firstSessionFile = runtime.session.sessionFile!;
+		await runtime.newSession();
+		await runtime.session.bindExtensions({});
+
+		faux.setResponses([fauxAssistantMessage(fauxToolCall("block", {}), { stopReason: "toolUse" })]);
+		const outgoingSession = runtime.session;
+		const promptPromise = outgoingSession.prompt("start blocking tool");
+		await toolStartedPromise;
+
+		const switchResult = await runtime.switchSession(firstSessionFile);
+		await promptPromise;
+
+		expect(switchResult.cancelled).toBe(false);
+		expect(runtime.session.sessionFile).toBe(firstSessionFile);
+		// The outgoing session settled before replacement: the interrupted tool
+		// call has a persisted tool result instead of dangling forever.
+		const outgoingEntries = SessionManager.open(outgoingSession.sessionFile!)
+			.getEntries()
+			.filter((entry) => entry.type === "message");
+		expect(outgoingEntries.map((entry) => entry.message.role)).toEqual([
+			"user",
+			"assistant",
+			"toolResult",
+			"assistant",
+		]);
+	});
+
+	it("preserves an existing session when importing a file with the same name", async () => {
+		const { runtime, tempDir } = await createRuntimeForTest(() => {});
+		const sessionDir = runtime.session.sessionManager.getSessionDir();
+		const importDir = join(tempDir, "import");
+		const filename = "collision.jsonl";
+		const storedPath = join(sessionDir, filename);
+		const importPath = join(importDir, filename);
+		const storedSession = `${JSON.stringify({
+			type: "session",
+			version: 3,
+			id: "stored",
+			timestamp: new Date().toISOString(),
+			cwd: tempDir,
+		})}\n`;
+		const importedSession = `${JSON.stringify({
+			type: "session",
+			version: 3,
+			id: "imported",
+			timestamp: new Date().toISOString(),
+			cwd: tempDir,
+		})}\n`;
+		mkdirSync(sessionDir, { recursive: true });
+		mkdirSync(importDir, { recursive: true });
+		writeFileSync(storedPath, storedSession);
+		writeFileSync(importPath, importedSession);
+
+		await runtime.importFromJsonl(importPath);
+
+		expect(readFileSync(storedPath, "utf8")).toBe(storedSession);
+		expect(runtime.session.sessionFile).not.toBe(storedPath);
+		expect(readFileSync(runtime.session.sessionFile!, "utf8")).toContain('"id":"imported"');
+	});
+
+	it("emits session_before_switch and session_start for new and resume flows", async () => {
+		const events: RecordedSessionEvent[] = [];
+		const { runtime } = await createRuntimeForTest((pi: ExtensionAPI) => {
+			pi.on("session_before_switch", (event) => {
+				events.push(event);
+			});
+			pi.on("session_shutdown", (event) => {
+				events.push(event);
+			});
+			pi.on("session_start", (event) => {
+				events.push(event);
+			});
+		});
+
+		expect(events).toEqual([{ type: "session_start", reason: "startup" }]);
+		events.length = 0;
+
+		await runtime.session.prompt("hello");
+		const originalSessionFile = runtime.session.sessionFile;
+		const originalSession = runtime.session;
+
+		const newSessionResult = await runtime.newSession();
+		expect(newSessionResult.cancelled).toBe(false);
+		await runtime.session.bindExtensions({});
+		expect(runtime.session).not.toBe(originalSession);
+		expect(runtime.session.messages).toEqual([]);
+		const secondSessionFile = runtime.session.sessionFile;
+		expect(events).toEqual([
+			{ type: "session_before_switch", reason: "new", targetSessionFile: undefined },
+			{ type: "session_shutdown", reason: "new", targetSessionFile: secondSessionFile },
+			{ type: "session_start", reason: "new", previousSessionFile: originalSessionFile },
+		]);
+
+		events.length = 0;
+
+		const switchResult = await runtime.switchSession(originalSessionFile!);
+		expect(switchResult.cancelled).toBe(false);
+		await runtime.session.bindExtensions({});
+		expect(events).toEqual([
+			{ type: "session_before_switch", reason: "resume", targetSessionFile: originalSessionFile },
+			{ type: "session_shutdown", reason: "resume", targetSessionFile: originalSessionFile },
+			{ type: "session_start", reason: "resume", previousSessionFile: secondSessionFile },
+		]);
+	});
+
+	it("honors session_before_switch cancellation for new and resume", async () => {
+		const events: RecordedSessionEvent[] = [];
+		let cancelReason: "new" | "resume" | undefined;
+		const { runtime } = await createRuntimeForTest((pi: ExtensionAPI) => {
+			pi.on("session_before_switch", (event) => {
+				events.push(event);
+				if (event.reason === cancelReason) {
+					return { cancel: true };
+				}
+			});
+			pi.on("session_start", (event) => {
+				events.push(event);
+			});
+		});
+
+		await runtime.session.prompt("hello");
+		const originalSessionFile = runtime.session.sessionFile;
+
+		cancelReason = "new";
+		const newResult = await runtime.newSession();
+		expect(newResult.cancelled).toBe(true);
+		expect(runtime.session.sessionFile).toBe(originalSessionFile);
+
+		events.length = 0;
+		const otherDir = join(tmpdir(), `pi-runtime-other-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		mkdirSync(otherDir, { recursive: true });
+		const otherSession = SessionManager.create(otherDir);
+		otherSession.appendMessage({ role: "user", content: [{ type: "text", text: "other" }], timestamp: Date.now() });
+		const otherSessionFile = otherSession.getSessionFile();
+		cancelReason = "resume";
+		const resumeResult = await runtime.switchSession(otherSessionFile!);
+		expect(resumeResult.cancelled).toBe(true);
+		expect(runtime.session.sessionFile).toBe(originalSessionFile);
+	});
+
+	it("emits session_before_fork and session_start and honors cancellation", async () => {
+		const events: RecordedSessionEvent[] = [];
+		let cancelNextFork = false;
+		const { runtime } = await createRuntimeForTest((pi: ExtensionAPI) => {
+			pi.on("session_before_fork", (event) => {
+				events.push(event);
+				if (cancelNextFork) {
+					cancelNextFork = false;
+					return { cancel: true };
+				}
+			});
+			pi.on("session_shutdown", (event) => {
+				events.push(event);
+			});
+			pi.on("session_start", (event) => {
+				events.push(event);
+			});
+		});
+
+		events.length = 0;
+		await runtime.session.prompt("hello");
+		const userMessage = runtime.session.getUserMessagesForForking()[0]!;
+		const previousSessionFile = runtime.session.sessionFile;
+
+		const successResult = await runtime.fork(userMessage.entryId);
+		expect(successResult.cancelled).toBe(false);
+		expect(successResult.selectedText).toBe("hello");
+		await runtime.session.bindExtensions({});
+		expect(events).toEqual([
+			{ type: "session_before_fork", entryId: userMessage.entryId, position: "before" },
+			{ type: "session_shutdown", reason: "fork", targetSessionFile: runtime.session.sessionFile },
+			{ type: "session_start", reason: "fork", previousSessionFile },
+		]);
+		const sessionFileName = parse(runtime.session.sessionFile!).name;
+		expect(sessionFileName.endsWith(`_${runtime.session.sessionId}`)).toBe(true);
+
+		events.length = 0;
+		cancelNextFork = true;
+		const cancelResult = await runtime.fork(userMessage.entryId);
+		expect(cancelResult).toEqual({ cancelled: true });
+		expect(events).toEqual([{ type: "session_before_fork", entryId: userMessage.entryId, position: "before" }]);
+
+		events.length = 0;
+		cancelNextFork = true;
+		const cancelAtResult = await runtime.fork("missing-entry", { position: "at" });
+		expect(cancelAtResult).toEqual({ cancelled: true });
+		expect(events).toEqual([{ type: "session_before_fork", entryId: "missing-entry", position: "at" }]);
+	});
+
+	it("reports why an unflushed session cannot be forked", async () => {
+		const { runtime } = await createRuntimeForTest(() => {});
+		const sessionFile = runtime.session.sessionFile;
+		const leafId = runtime.session.sessionManager.getLeafId();
+		expect(sessionFile).toBeDefined();
+		expect(existsSync(sessionFile!)).toBe(false);
+		expect(leafId).toBeTruthy();
+
+		await expect(runtime.fork(leafId!, { position: "at" })).rejects.toThrow(
+			"This session has not been saved yet. Wait for the first assistant response before cloning or forking it.",
+		);
+	});
+
+	it("duplicates the current active branch when forking at the current position", async () => {
+		const { runtime } = await createRuntimeForTest(() => {});
+		await runtime.session.prompt("hello");
+		await runtime.session.prompt("again");
+
+		const beforeMessages = runtime.session.messages.map((message) => ({
+			role: message.role,
+			text:
+				message.role === "user"
+					? typeof message.content === "string"
+						? message.content
+						: message.content
+								.filter((part): part is { type: "text"; text: string } => part.type === "text")
+								.map((part) => part.text)
+								.join("")
+					: undefined,
+		}));
+		const previousSessionFile = runtime.session.sessionFile;
+		const leafId = runtime.session.sessionManager.getLeafId();
+		expect(leafId).toBeTruthy();
+
+		const result = await runtime.fork(leafId!, { position: "at" });
+		expect(result).toEqual({ cancelled: false, selectedText: undefined });
+		expect(runtime.session.sessionFile).not.toBe(previousSessionFile);
+		expect(
+			runtime.session.messages.map((message) => ({
+				role: message.role,
+				text:
+					message.role === "user"
+						? typeof message.content === "string"
+							? message.content
+							: message.content
+									.filter((part): part is { type: "text"; text: string } => part.type === "text")
+									.map((part) => part.text)
+									.join("")
+						: undefined,
+			})),
+		).toEqual(beforeMessages);
+	});
+
+	it("duplicates the current active branch in-memory when forking at the current position", async () => {
+		const tempDir = join(tmpdir(), `pi-runtime-suite-in-memory-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		mkdirSync(tempDir, { recursive: true });
+
+		const faux = registerFauxProvider({
+			models: [
+				{ id: "faux-1", reasoning: true },
+				{ id: "faux-2", reasoning: false },
+			],
+		});
+		faux.setResponses([fauxAssistantMessage("one"), fauxAssistantMessage("two"), fauxAssistantMessage("three")]);
+
+		const authStorage = AuthStorage.inMemory();
+		await authStorage.modify(faux.getModel().provider, async () => ({ type: "api_key", key: "faux-key" }));
+
+		const runtimeOptions = {
+			agentDir: tempDir,
+			authStorage,
+			model: faux.getModel(),
+			resourceLoaderOptions: {
+				extensionFactories: [
+					(pi: ExtensionAPI) => {
+						pi.registerProvider(faux.getModel().provider, {
+							baseUrl: faux.getModel().baseUrl,
+							apiKey: "faux-key",
+							api: faux.api,
+							models: faux.models.map((registeredModel) => ({
+								id: registeredModel.id,
+								name: registeredModel.name,
+								api: registeredModel.api,
+								reasoning: registeredModel.reasoning,
+								input: registeredModel.input,
+								cost: registeredModel.cost,
+								contextWindow: registeredModel.contextWindow,
+								maxTokens: registeredModel.maxTokens,
+							})),
+						});
+					},
+				],
+				noSkills: true,
+				noPromptTemplates: true,
+				noThemes: true,
+			},
+		};
+		const createRuntime: CreateAgentSessionRuntimeFactory = async ({ cwd, sessionManager, sessionStartEvent }) => {
+			const services = await createAgentSessionServices({
+				...runtimeOptions,
+				cwd,
+			});
+			return {
+				...(await createAgentSessionFromServices({
+					services,
+					sessionManager,
+					sessionStartEvent,
+					model: runtimeOptions.model,
+				})),
+				services,
+				diagnostics: services.diagnostics,
+			};
+		};
+		const runtime = await createAgentSessionRuntime(createRuntime, {
+			cwd: tempDir,
+			agentDir: tempDir,
+			sessionManager: SessionManager.inMemory(tempDir),
+		});
+		await runtime.session.bindExtensions({});
+		cleanups.push(async () => {
+			await runtime.dispose();
+			faux.unregister();
+			if (existsSync(tempDir)) {
+				rmSync(tempDir, { recursive: true, force: true });
+			}
+		});
+
+		await runtime.session.prompt("hello");
+		await runtime.session.prompt("again");
+
+		const beforeMessages = runtime.session.messages.map((message) => ({
+			role: message.role,
+			text:
+				message.role === "user"
+					? typeof message.content === "string"
+						? message.content
+						: message.content
+								.filter((part): part is { type: "text"; text: string } => part.type === "text")
+								.map((part) => part.text)
+								.join("")
+					: undefined,
+		}));
+		const leafId = runtime.session.sessionManager.getLeafId();
+		expect(leafId).toBeTruthy();
+		expect(runtime.session.sessionFile).toBeUndefined();
+
+		const result = await runtime.fork(leafId!, { position: "at" });
+		expect(result).toEqual({ cancelled: false, selectedText: undefined });
+		expect(runtime.session.sessionFile).toBeUndefined();
+		expect(
+			runtime.session.messages.map((message) => ({
+				role: message.role,
+				text:
+					message.role === "user"
+						? typeof message.content === "string"
+							? message.content
+							: message.content
+									.filter((part): part is { type: "text"; text: string } => part.type === "text")
+									.map((part) => part.text)
+									.join("")
+						: undefined,
+			})),
+		).toEqual(beforeMessages);
+	});
+
+	it("throws when forking with an invalid entry id", async () => {
+		const { runtime } = await createRuntimeForTest(() => {});
+		await expect(runtime.fork("missing-entry")).rejects.toThrow("Invalid entry ID for forking");
+	});
+
+	it("updates the runtime session cwd on cross-cwd session replacement", async () => {
+		const firstDir = join(tmpdir(), `pi-runtime-cwd-a-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		const secondDir = join(tmpdir(), `pi-runtime-cwd-b-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		mkdirSync(firstDir, { recursive: true });
+		mkdirSync(secondDir, { recursive: true });
+		const { runtime, faux, tempDir } = await createRuntimeForTest(() => {}, { cwd: firstDir });
+		const otherAuthStorage = AuthStorage.inMemory();
+		await otherAuthStorage.modify(faux.getModel().provider, async () => ({ type: "api_key", key: "faux-key" }));
+		const otherRuntimeOptions = {
+			agentDir: tempDir,
+			authStorage: otherAuthStorage,
+			resourceLoaderOptions: {
+				extensionFactories: [
+					(pi: ExtensionAPI) => {
+						pi.registerProvider(faux.getModel().provider, {
+							baseUrl: faux.getModel().baseUrl,
+							apiKey: "faux-key",
+							api: faux.api,
+							models: faux.models.map((registeredModel) => ({
+								id: registeredModel.id,
+								name: registeredModel.name,
+								api: registeredModel.api,
+								reasoning: registeredModel.reasoning,
+								input: registeredModel.input,
+								cost: registeredModel.cost,
+								contextWindow: registeredModel.contextWindow,
+								maxTokens: registeredModel.maxTokens,
+							})),
+						});
+					},
+				],
+				noSkills: true,
+				noPromptTemplates: true,
+				noThemes: true,
+			},
+		};
+		const createOtherRuntime: CreateAgentSessionRuntimeFactory = async ({
+			cwd,
+			sessionManager,
+			sessionStartEvent,
+		}) => {
+			const services = await createAgentSessionServices({
+				...otherRuntimeOptions,
+				cwd,
+			});
+			return {
+				...(await createAgentSessionFromServices({
+					services,
+					sessionManager,
+					sessionStartEvent,
+				})),
+				services,
+				diagnostics: services.diagnostics,
+			};
+		};
+		const otherRuntime = await createAgentSessionRuntime(createOtherRuntime, {
+			cwd: secondDir,
+			agentDir: tempDir,
+			sessionManager: SessionManager.create(secondDir),
+		});
+		cleanups.push(async () => {
+			await otherRuntime.dispose();
+		});
+		await otherRuntime.session.prompt("other");
+		const otherSessionFile = otherRuntime.session.sessionFile!;
+
+		await runtime.switchSession(otherSessionFile);
+
+		expect(realpathSync(runtime.session.sessionManager.getCwd())).toBe(realpathSync(secondDir));
+		expect(realpathSync(runtime.cwd)).toBe(realpathSync(secondDir));
+	});
+
+	it("restores model and thinking state from the destination session", async () => {
+		const { runtime, faux, tempDir } = await createRuntimeForTest(() => {}, {
+			bootstrapModel: false,
+			bootstrapThinkingLevel: false,
+		});
+		const otherDir = join(tempDir, "other");
+		mkdirSync(otherDir, { recursive: true });
+		const otherAuthStorage = AuthStorage.inMemory();
+		await otherAuthStorage.modify(faux.getModel().provider, async () => ({ type: "api_key", key: "faux-key" }));
+		const otherRuntimeOptions = {
+			agentDir: tempDir,
+			authStorage: otherAuthStorage,
+			resourceLoaderOptions: {
+				extensionFactories: [
+					(pi: ExtensionAPI) => {
+						pi.registerProvider(faux.getModel().provider, {
+							baseUrl: faux.getModel().baseUrl,
+							apiKey: "faux-key",
+							api: faux.api,
+							models: faux.models.map((registeredModel) => ({
+								id: registeredModel.id,
+								name: registeredModel.name,
+								api: registeredModel.api,
+								reasoning: registeredModel.reasoning,
+								input: registeredModel.input,
+								cost: registeredModel.cost,
+								contextWindow: registeredModel.contextWindow,
+								maxTokens: registeredModel.maxTokens,
+							})),
+						});
+					},
+				],
+				noSkills: true,
+				noPromptTemplates: true,
+				noThemes: true,
+			},
+		};
+		const createOtherRuntime: CreateAgentSessionRuntimeFactory = async ({
+			cwd,
+			sessionManager,
+			sessionStartEvent,
+		}) => {
+			const services = await createAgentSessionServices({
+				...otherRuntimeOptions,
+				cwd,
+			});
+			return {
+				...(await createAgentSessionFromServices({
+					services,
+					sessionManager,
+					sessionStartEvent,
+				})),
+				services,
+				diagnostics: services.diagnostics,
+			};
+		};
+		const otherRuntime = await createAgentSessionRuntime(createOtherRuntime, {
+			cwd: otherDir,
+			agentDir: tempDir,
+			sessionManager: SessionManager.create(otherDir),
+		});
+		cleanups.push(async () => {
+			await otherRuntime.dispose();
+		});
+		await otherRuntime.session.setModel(faux.getModel("faux-2")!);
+		otherRuntime.session.setThinkingLevel("off");
+		await otherRuntime.session.prompt("hello");
+		const targetSessionFile = otherRuntime.session.sessionFile!;
+
+		await runtime.switchSession(targetSessionFile);
+
+		expect(runtime.session.model?.id).toBe("faux-2");
+		expect(runtime.session.thinkingLevel).toBe("off");
+	});
+});

packages/coding-agent/test/suite/agent-session-tool-result-images.test.ts

@@ -0,0 +1,52 @@
+import type { AgentTool } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { createHarness, type Harness } from "./harness.ts";
+
+const normalizeToolResultImages = vi.hoisted(() => vi.fn(async (content: unknown[]) => content));
+vi.mock("../../src/utils/tool-result-images.ts", () => ({ normalizeToolResultImages }));
+
+const TINY_PNG_BASE64 =
+	"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8DwHwAFBQIAX8jx0gAAAABJRU5ErkJggg==";
+
+const screenshotTool: AgentTool = {
+	name: "screenshot",
+	label: "Screenshot",
+	description: "Return a screenshot",
+	parameters: Type.Object({}),
+	execute: async () => ({
+		content: [
+			{ type: "text", text: "captured" },
+			{ type: "image", data: TINY_PNG_BASE64, mimeType: "image/png" },
+		],
+		details: {},
+	}),
+};
+
+describe("AgentSession tool result images", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		normalizeToolResultImages.mockClear();
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("passes images.autoResize to tool result normalization", async () => {
+		const harness = await createHarness({
+			tools: [screenshotTool],
+			settings: { images: { autoResize: false } },
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage([fauxToolCall("screenshot", {})], { stopReason: "toolUse" }),
+			fauxAssistantMessage("done"),
+		]);
+
+		await harness.session.prompt("take a screenshot");
+
+		expect(normalizeToolResultImages).toHaveBeenCalledWith(expect.any(Array), { autoResizeImages: false });
+	});
+});

packages/coding-agent/test/suite/harness.ts

@@ -0,0 +1,225 @@
+import { createInMemoryModelRegistry, createModelRegistry, getModelRuntime } from "../model-runtime-test-utils.ts";
+/**
+ * Local test harness for the new coding-agent test suite.
+ */
+
+import { existsSync, mkdirSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import type { AgentMessage, AgentTool } from "@earendil-works/pi-agent-core";
+import { Agent } from "@earendil-works/pi-agent-core";
+import type {
+	FauxModelDefinition,
+	FauxProviderRegistration,
+	FauxResponseStep,
+	Model,
+} from "@earendil-works/pi-ai/compat";
+import { registerFauxProvider, streamSimple } from "@earendil-works/pi-ai/compat";
+import { AgentSession, type AgentSessionEvent } from "../../src/core/agent-session.ts";
+import { AuthStorage } from "../../src/core/auth-storage.ts";
+import type { ExtensionRunner } from "../../src/core/extensions/index.ts";
+import { convertToLlm } from "../../src/core/messages.ts";
+import { SessionManager } from "../../src/core/session-manager.ts";
+import type { Settings } from "../../src/core/settings-manager.ts";
+import { SettingsManager } from "../../src/core/settings-manager.ts";
+import type { InlineExtension, ResourceLoader } from "../../src/index.ts";
+import {
+	type CreateTestExtensionsResultInput,
+	createTestExtensionsResult,
+	createTestResourceLoader,
+} from "../utilities.ts";
+
+type MessageTextPart = { type: "text"; text: string };
+
+export function getMessageText(message: unknown): string {
+	if (!message || typeof message !== "object" || !("content" in message)) {
+		return "";
+	}
+	const content = (message as { content?: string | Array<{ type: string; text?: string }> }).content;
+	if (content === undefined) {
+		return "";
+	}
+	if (typeof content === "string") {
+		return content;
+	}
+	return content
+		.filter((part): part is MessageTextPart => part.type === "text")
+		.map((part) => part.text)
+		.join("\n");
+}
+
+export function getUserTexts(harness: Harness): string[] {
+	return harness.session.messages
+		.filter((message) => message.role === "user")
+		.map((message) => getMessageText(message));
+}
+
+export function getAssistantTexts(harness: Harness): string[] {
+	return harness.session.messages
+		.filter((message) => message.role === "assistant")
+		.map((message) => getMessageText(message));
+}
+
+export interface HarnessOptions {
+	models?: FauxModelDefinition[];
+	settings?: Partial<Settings>;
+	systemPrompt?: string;
+	tools?: AgentTool[];
+	initialActiveToolNames?: string[];
+	allowedToolNames?: string[];
+	excludedToolNames?: string[];
+	resourceLoader?: ResourceLoader;
+	extensionFactories?: Array<InlineExtension | CreateTestExtensionsResultInput>;
+	withConfiguredAuth?: boolean;
+	modelsJson?: Record<string, unknown>;
+}
+
+export interface Harness {
+	session: AgentSession;
+	sessionManager: SessionManager;
+	settingsManager: SettingsManager;
+	authStorage: AuthStorage;
+	faux: FauxProviderRegistration;
+	models: [Model<string>, ...Model<string>[]];
+	getModel(): Model<string>;
+	getModel(modelId: string): Model<string> | undefined;
+	setResponses: (responses: FauxResponseStep[]) => void;
+	appendResponses: (responses: FauxResponseStep[]) => void;
+	getPendingResponseCount: () => number;
+	events: AgentSessionEvent[];
+	eventsOfType<T extends AgentSessionEvent["type"]>(type: T): Extract<AgentSessionEvent, { type: T }>[];
+	tempDir: string;
+	cleanup: () => void;
+}
+
+function createTempDir(): string {
+	const tempDir = join(tmpdir(), `pi-suite-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+	mkdirSync(tempDir, { recursive: true });
+	return tempDir;
+}
+
+export async function createHarness(options: HarnessOptions = {}): Promise<Harness> {
+	const tempDir = createTempDir();
+	const fauxProvider: FauxProviderRegistration = registerFauxProvider({
+		models: options.models,
+	});
+	fauxProvider.setResponses([]);
+	const model = fauxProvider.getModel();
+	const toolMap = options.tools ? Object.fromEntries(options.tools.map((tool) => [tool.name, tool])) : undefined;
+	const withConfiguredAuth = options.withConfiguredAuth ?? true;
+	const extensionRunnerRef: { current?: ExtensionRunner } = {};
+
+	const sessionManager = SessionManager.inMemory();
+	const settingsManager = SettingsManager.inMemory(options.settings);
+
+	const authStorage = AuthStorage.inMemory();
+	if (withConfiguredAuth) {
+		await authStorage.modify(model.provider, async () => ({ type: "api_key", key: "faux-key" }));
+	}
+	const modelsPath = options.modelsJson === undefined ? undefined : join(tempDir, "models.json");
+	if (modelsPath) writeFileSync(modelsPath, JSON.stringify(options.modelsJson));
+	const modelRegistry = modelsPath
+		? await createModelRegistry(authStorage, modelsPath)
+		: await createInMemoryModelRegistry(authStorage);
+	if (withConfiguredAuth) {
+		modelRegistry.registerProvider(model.provider, {
+			baseUrl: model.baseUrl,
+			apiKey: "faux-key",
+			api: fauxProvider.api,
+			models: fauxProvider.models.map((registeredModel) => ({
+				id: registeredModel.id,
+				name: registeredModel.name,
+				api: registeredModel.api,
+				reasoning: registeredModel.reasoning,
+				input: registeredModel.input,
+				cost: registeredModel.cost,
+				contextWindow: registeredModel.contextWindow,
+				maxTokens: registeredModel.maxTokens,
+				baseUrl: registeredModel.baseUrl,
+			})),
+		});
+	}
+
+	const agent = new Agent({
+		getApiKey: () => (withConfiguredAuth ? "faux-key" : undefined),
+		streamFn: streamSimple,
+		initialState: {
+			model,
+			systemPrompt: options.systemPrompt ?? "You are a test assistant.",
+			tools: [],
+		},
+		convertToLlm,
+		onPayload: async (payload) => {
+			const runner = extensionRunnerRef.current;
+			if (!runner?.hasHandlers("before_provider_request")) {
+				return payload;
+			}
+			return runner.emitBeforeProviderRequest(payload);
+		},
+		onResponse: async (response) => {
+			const runner = extensionRunnerRef.current;
+			if (!runner?.hasHandlers("after_provider_response")) {
+				return;
+			}
+			await runner.emit({
+				type: "after_provider_response",
+				status: response.status,
+				headers: response.headers,
+			});
+		},
+		transformContext: async (messages: AgentMessage[]) => {
+			const runner = extensionRunnerRef.current;
+			if (!runner) return messages;
+			return runner.emitContext(messages);
+		},
+	});
+	const extensionsResult = options.extensionFactories
+		? await createTestExtensionsResult(options.extensionFactories, tempDir)
+		: undefined;
+	const resourceLoader =
+		options.resourceLoader ?? createTestResourceLoader(extensionsResult ? { extensionsResult } : undefined);
+
+	const session = new AgentSession({
+		agent,
+		sessionManager,
+		settingsManager,
+		cwd: tempDir,
+		modelRuntime: getModelRuntime(modelRegistry),
+		resourceLoader,
+		baseToolsOverride: toolMap,
+		initialActiveToolNames: options.initialActiveToolNames,
+		allowedToolNames: options.allowedToolNames,
+		excludedToolNames: options.excludedToolNames,
+		extensionRunnerRef,
+	});
+
+	const events: AgentSessionEvent[] = [];
+	session.subscribe((event) => {
+		events.push(event);
+	});
+
+	return {
+		session,
+		sessionManager,
+		settingsManager,
+		authStorage,
+		faux: fauxProvider,
+		models: fauxProvider.models,
+		getModel: fauxProvider.getModel,
+		setResponses: fauxProvider.setResponses,
+		appendResponses: fauxProvider.appendResponses,
+		getPendingResponseCount: fauxProvider.getPendingResponseCount,
+		events,
+		eventsOfType<T extends AgentSessionEvent["type"]>(type: T) {
+			return events.filter((event): event is Extract<AgentSessionEvent, { type: T }> => event.type === type);
+		},
+		tempDir,
+		cleanup() {
+			session.dispose();
+			fauxProvider.unregister();
+			if (existsSync(tempDir)) {
+				rmSync(tempDir, { recursive: true });
+			}
+		},
+	};
+}

packages/coding-agent/test/suite/lax-message-content.test.ts

@@ -0,0 +1,162 @@
+/**
+ * The Message types require `content` to always be present, but untyped JS
+ * extension tools, hand-built histories, and old or hand-edited session files
+ * can violate that contract. We are intentionally lax at the ingestion
+ * boundaries and normalize null/missing content to an empty array so it never
+ * reaches rendering, compaction, or provider request conversion
+ * (issues #6259, #6276).
+ */
+
+import type { AgentMessage, AgentToolResult } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { describe, expect, it } from "vitest";
+import { type SessionEntry, sessionEntryToContextMessages } from "../../src/core/session-manager.ts";
+import type { ExtensionFactory } from "../../src/index.ts";
+import { createHarness } from "./harness.ts";
+
+function messageEntry(message: Record<string, unknown>): SessionEntry {
+	return {
+		type: "message",
+		id: "entry-1",
+		parentId: null,
+		timestamp: new Date().toISOString(),
+		message,
+	} as unknown as SessionEntry;
+}
+
+describe("lax message content handling", () => {
+	it("normalizes tool results from untyped tools that omit content", async () => {
+		const extensionFactories: ExtensionFactory[] = [
+			(pi) => {
+				pi.registerTool({
+					name: "web_search",
+					label: "Web Search",
+					description: "Custom tool that returns a result without content",
+					parameters: Type.Object({}),
+					// Simulate an untyped JS extension tool that omits content.
+					execute: async () => ({ details: {} }) as unknown as AgentToolResult<unknown>,
+				});
+			},
+		];
+		const harness = await createHarness({ extensionFactories });
+
+		try {
+			harness.setResponses([
+				fauxAssistantMessage(fauxToolCall("web_search", {}), { stopReason: "toolUse" }),
+				fauxAssistantMessage("done"),
+			]);
+
+			await harness.session.prompt("search something");
+
+			const toolResults = harness.session.messages.filter((message) => message.role === "toolResult");
+			expect(toolResults).toHaveLength(1);
+			expect(toolResults[0].content).toEqual([]);
+			// The follow-up turn consumed the normalized tool result without crashing.
+			expect(harness.getPendingResponseCount()).toBe(0);
+		} finally {
+			harness.cleanup();
+		}
+	});
+
+	it("normalizes null content in message_end extension replacements", async () => {
+		const extensionFactories: ExtensionFactory[] = [
+			(pi) => {
+				pi.on("message_end", async (event) => {
+					if (event.message.role !== "assistant") return undefined;
+					// Simulate an untyped JS extension replacing a message without content.
+					return { message: { ...event.message, content: null } as unknown as AgentMessage };
+				});
+			},
+		];
+		const harness = await createHarness({ extensionFactories });
+
+		try {
+			harness.setResponses([fauxAssistantMessage("hello")]);
+			await harness.session.prompt("hi");
+
+			const assistantMessages = harness.session.messages.filter((message) => message.role === "assistant");
+			expect(assistantMessages).toHaveLength(1);
+			expect(assistantMessages[0].content).toEqual([]);
+		} finally {
+			harness.cleanup();
+		}
+	});
+
+	it("normalizes null content in custom messages from extensions", async () => {
+		const harness = await createHarness();
+
+		try {
+			await harness.session.sendCustomMessage({
+				customType: "test",
+				content: null as unknown as string,
+				display: false,
+				details: undefined,
+			});
+
+			const customMessages = harness.session.messages.filter((message) => message.role === "custom");
+			expect(customMessages).toHaveLength(1);
+			expect(customMessages[0].content).toEqual([]);
+		} finally {
+			harness.cleanup();
+		}
+	});
+
+	it("normalizes null or missing content when loading session message entries", () => {
+		const badMessages = [
+			{ role: "user", content: null, timestamp: Date.now() },
+			{
+				role: "assistant",
+				content: null,
+				api: "openai-completions",
+				provider: "openai",
+				model: "test-model",
+				usage: {
+					input: 0,
+					output: 0,
+					cacheRead: 0,
+					cacheWrite: 0,
+					totalTokens: 0,
+					cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+				},
+				stopReason: "stop",
+				timestamp: Date.now(),
+			},
+			{
+				role: "toolResult",
+				toolCallId: "call_1",
+				toolName: "web_search",
+				isError: false,
+				timestamp: Date.now(),
+			},
+		];
+
+		for (const badMessage of badMessages) {
+			const [message] = sessionEntryToContextMessages(messageEntry(badMessage));
+			expect(message).toMatchObject({ role: badMessage.role, content: [] });
+		}
+	});
+
+	it("normalizes null content when loading custom message entries", () => {
+		const entry = {
+			type: "custom_message",
+			id: "entry-1",
+			parentId: null,
+			timestamp: new Date().toISOString(),
+			customType: "test",
+			content: null,
+			display: false,
+			details: undefined,
+		} as unknown as SessionEntry;
+
+		const [message] = sessionEntryToContextMessages(entry);
+		expect(message).toMatchObject({ role: "custom", content: [] });
+	});
+
+	it("keeps valid message content untouched when loading session entries", () => {
+		const [message] = sessionEntryToContextMessages(
+			messageEntry({ role: "user", content: "hello", timestamp: Date.now() }),
+		);
+		expect(message).toMatchObject({ role: "user", content: "hello" });
+	});
+});

packages/coding-agent/test/suite/regressions/1717-2113-agent-session-event-settlement.test.ts

@@ -0,0 +1,95 @@
+import type { AgentTool } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, type Harness } from "../harness.ts";
+
+function createEchoTool(): AgentTool {
+	return {
+		name: "echo",
+		label: "Echo",
+		description: "Echo text back",
+		parameters: Type.Object({ text: Type.String() }),
+		execute: async (_toolCallId, params) => {
+			const text = typeof params === "object" && params !== null && "text" in params ? String(params.text) : "";
+			return { content: [{ type: "text", text }], details: { text } };
+		},
+	};
+}
+
+describe("regressions #1717/#2113: agent session event settlement", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("keeps persisted assistant/toolResult message order when extension message_end handlers yield", async () => {
+		const harness = await createHarness({
+			tools: [createEchoTool()],
+			extensionFactories: [
+				(pi) => {
+					pi.on("message_end", async (event) => {
+						if (event.message.role === "assistant") {
+							await new Promise((resolve) => setTimeout(resolve, 20));
+						}
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage([fauxToolCall("echo", { text: "one" }), fauxToolCall("echo", { text: "two" })], {
+				stopReason: "toolUse",
+			}),
+			fauxAssistantMessage("done"),
+		]);
+		await harness.session.prompt("run tools");
+
+		const branchMessages = harness.sessionManager
+			.getBranch()
+			.filter((entry) => entry.type === "message")
+			.map((entry) => entry.message);
+		expect(branchMessages.map((message) => message.role)).toEqual([
+			"user",
+			"assistant",
+			"toolResult",
+			"toolResult",
+			"assistant",
+		]);
+		const firstToolResultIndex = branchMessages.findIndex((message) => message.role === "toolResult");
+		expect(firstToolResultIndex).toBeGreaterThan(0);
+		expect(branchMessages[firstToolResultIndex - 1]?.role).toBe("assistant");
+	});
+
+	it("runs tool_call handlers after the assistant tool-use message is settled in the session", async () => {
+		let harness: Harness;
+		const branchRolesAtToolCall: string[][] = [];
+		harness = await createHarness({
+			tools: [createEchoTool()],
+			extensionFactories: [
+				(pi) => {
+					pi.on("tool_call", () => {
+						branchRolesAtToolCall.push(
+							harness.sessionManager
+								.getBranch()
+								.filter((entry) => entry.type === "message")
+								.map((entry) => entry.message.role),
+						);
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage([fauxToolCall("echo", { text: "hello" })], { stopReason: "toolUse" }),
+			fauxAssistantMessage("done"),
+		]);
+
+		await harness.session.prompt("run tool");
+
+		expect(branchRolesAtToolCall).toEqual([["user", "assistant"]]);
+	});
+});

packages/coding-agent/test/suite/regressions/2023-queued-slash-command-followup.test.ts

@@ -0,0 +1,80 @@
+import type { AgentTool } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, getAssistantTexts, getUserTexts, type Harness } from "../harness.ts";
+
+describe("issue #2023 queued slash-command follow-up", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("treats extension-origin queued slash-command follow-ups as raw user text instead of dispatching the command", async () => {
+		let extensionApi: ExtensionAPI | undefined;
+		const commandRuns: string[] = [];
+		let releaseToolExecution: (() => void) | undefined;
+		const toolRelease = new Promise<void>((resolve) => {
+			releaseToolExecution = resolve;
+		});
+		const waitTool: AgentTool = {
+			name: "wait",
+			label: "Wait",
+			description: "Wait for the test to release execution",
+			parameters: Type.Object({}),
+			execute: async () => {
+				await toolRelease;
+				return {
+					content: [{ type: "text", text: "released" }],
+					details: {},
+				};
+			},
+		};
+		const harness = await createHarness({
+			tools: [waitTool],
+			extensionFactories: [
+				(pi) => {
+					extensionApi = pi;
+					pi.registerCommand("testcmd", {
+						description: "Test command",
+						handler: async (args) => {
+							commandRuns.push(args);
+						},
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("wait", {}), { stopReason: "toolUse" }),
+			fauxAssistantMessage("first turn complete"),
+			fauxAssistantMessage("queued follow-up handled by model"),
+		]);
+
+		const sawToolStart = new Promise<void>((resolve) => {
+			const unsubscribe = harness.session.subscribe((event) => {
+				if (event.type === "tool_execution_start" && event.toolName === "wait") {
+					unsubscribe();
+					resolve();
+				}
+			});
+		});
+
+		const promptPromise = harness.session.prompt("start");
+		await sawToolStart;
+		await new Promise((resolve) => setTimeout(resolve, 0));
+
+		extensionApi?.sendUserMessage("/testcmd queued", { deliverAs: "followUp" });
+		releaseToolExecution?.();
+		await promptPromise;
+
+		expect(commandRuns).toEqual([]);
+		expect(getUserTexts(harness)).toEqual(["start", "/testcmd queued"]);
+		expect(getAssistantTexts(harness)).toContain("queued follow-up handled by model");
+	});
+});

packages/coding-agent/test/suite/regressions/2753-reload-stale-resource-settings.test.ts

@@ -0,0 +1,105 @@
+import { existsSync, mkdirSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { registerFauxProvider } from "@earendil-works/pi-ai/compat";
+import { afterEach, describe, expect, it } from "vitest";
+import {
+	type CreateAgentSessionRuntimeFactory,
+	createAgentSessionFromServices,
+	createAgentSessionRuntime,
+	createAgentSessionServices,
+} from "../../../src/core/agent-session-runtime.ts";
+import { AuthStorage } from "../../../src/core/auth-storage.ts";
+import { ModelRuntime } from "../../../src/core/model-runtime.ts";
+import { SessionManager } from "../../../src/core/session-manager.ts";
+
+describe("issue #2753 reload stale resource settings", () => {
+	const cleanups: Array<() => void> = [];
+
+	afterEach(() => {
+		while (cleanups.length > 0) {
+			cleanups.pop()?.();
+		}
+	});
+
+	it("applies updated top-level prompt settings on reload after startup", async () => {
+		const tempDir = join(tmpdir(), `pi-2753-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		const agentDir = join(tempDir, "agent");
+		const promptsDir = join(agentDir, "prompts");
+		mkdirSync(promptsDir, { recursive: true });
+		writeFileSync(join(promptsDir, "test.md"), "Echo test prompt\n");
+
+		const faux = registerFauxProvider({
+			models: [{ id: "faux-1", reasoning: false }],
+		});
+		const authStorage = AuthStorage.inMemory();
+		await authStorage.modify(faux.getModel().provider, async () => ({ type: "api_key", key: "faux-key" }));
+		const modelRuntime = await ModelRuntime.create({
+			credentials: authStorage,
+			modelsPath: join(agentDir, "models.json"),
+		});
+
+		const createRuntime: CreateAgentSessionRuntimeFactory = async ({ cwd, sessionManager, sessionStartEvent }) => {
+			const services = await createAgentSessionServices({
+				cwd,
+				agentDir,
+				modelRuntime,
+				resourceLoaderOptions: {
+					extensionFactories: [
+						(pi) => {
+							pi.registerProvider(faux.getModel().provider, {
+								baseUrl: faux.getModel().baseUrl,
+								apiKey: "faux-key",
+								api: faux.api,
+								models: faux.models.map((registeredModel) => ({
+									id: registeredModel.id,
+									name: registeredModel.name,
+									api: registeredModel.api,
+									reasoning: registeredModel.reasoning,
+									input: registeredModel.input,
+									cost: registeredModel.cost,
+									contextWindow: registeredModel.contextWindow,
+									maxTokens: registeredModel.maxTokens,
+								})),
+							});
+						},
+					],
+					noSkills: true,
+					noThemes: true,
+				},
+			});
+			return {
+				...(await createAgentSessionFromServices({
+					services,
+					sessionManager,
+					sessionStartEvent,
+					model: faux.getModel(),
+				})),
+				services,
+				diagnostics: services.diagnostics,
+			};
+		};
+		const runtime = await createAgentSessionRuntime(createRuntime, {
+			cwd: tempDir,
+			agentDir,
+			sessionManager: SessionManager.create(tempDir),
+		});
+
+		cleanups.push(() => {
+			runtime.session.dispose();
+			faux.unregister();
+			if (existsSync(tempDir)) {
+				rmSync(tempDir, { recursive: true, force: true });
+			}
+		});
+
+		expect(runtime.session.promptTemplates.map((prompt) => prompt.name)).toContain("test");
+
+		writeFileSync(join(agentDir, "settings.json"), `${JSON.stringify({ prompts: ["-prompts/test.md"] }, null, 2)}\n`);
+
+		await runtime.session.reload();
+
+		expect(runtime.services.settingsManager.getGlobalSettings().prompts).toEqual(["-prompts/test.md"]);
+		expect(runtime.session.promptTemplates.map((prompt) => prompt.name)).not.toContain("test");
+	});
+});

packages/coding-agent/test/suite/regressions/2781-skill-collision-precedence.test.ts

@@ -0,0 +1,120 @@
+import { mkdirSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { DefaultResourceLoader } from "../../../src/core/resource-loader.ts";
+
+describe("issue #2781 skill collision precedence: user skills should override package skills", () => {
+	let tempDir: string;
+	let agentDir: string;
+	let cwd: string;
+
+	beforeEach(() => {
+		tempDir = join(tmpdir(), `pi-2781-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		agentDir = join(tempDir, "agent");
+		cwd = join(tempDir, "project");
+		mkdirSync(agentDir, { recursive: true });
+		mkdirSync(cwd, { recursive: true });
+	});
+
+	afterEach(() => {
+		rmSync(tempDir, { recursive: true, force: true });
+	});
+
+	function createPackageWithSkill(name: string, description: string): string {
+		const pkgDir = join(tempDir, `fake-package-${name}`);
+		const skillDir = join(pkgDir, "skills", name);
+		mkdirSync(skillDir, { recursive: true });
+		writeFileSync(
+			join(pkgDir, "package.json"),
+			JSON.stringify({ name: `fake-pkg-${name}`, version: "1.0.0", pi: { skills: [`skills/${name}`] } }, null, 2),
+		);
+		writeFileSync(
+			join(skillDir, "SKILL.md"),
+			`---\nname: ${name}\ndescription: ${description}\n---\nPackage skill content`,
+		);
+		return pkgDir;
+	}
+
+	function createUserSkill(name: string, description: string): string {
+		const skillDir = join(agentDir, "skills", name);
+		mkdirSync(skillDir, { recursive: true });
+		const skillPath = join(skillDir, "SKILL.md");
+		writeFileSync(skillPath, `---\nname: ${name}\ndescription: ${description}\n---\nUser skill content`);
+		return skillPath;
+	}
+
+	function createProjectSkill(name: string, description: string): string {
+		const skillDir = join(cwd, ".pi", "skills", name);
+		mkdirSync(skillDir, { recursive: true });
+		const skillPath = join(skillDir, "SKILL.md");
+		writeFileSync(skillPath, `---\nname: ${name}\ndescription: ${description}\n---\nProject skill content`);
+		return skillPath;
+	}
+
+	function createSettingsWithPackage(pkgDir: string, scope: "user" | "project"): void {
+		const settingsDir = scope === "user" ? agentDir : join(cwd, ".pi");
+		mkdirSync(settingsDir, { recursive: true });
+		writeFileSync(join(settingsDir, "settings.json"), JSON.stringify({ packages: [pkgDir] }, null, 2));
+	}
+
+	it("user auto-discovered skill should override package skill with same name", async () => {
+		const pkgDir = createPackageWithSkill("web-fetch", "Package web-fetch skill");
+		const userSkillPath = createUserSkill("web-fetch", "User web-fetch override");
+		createSettingsWithPackage(pkgDir, "user");
+
+		const loader = new DefaultResourceLoader({ cwd, agentDir });
+		await loader.reload();
+
+		const { skills } = loader.getSkills();
+		const webFetch = skills.find((s) => s.name === "web-fetch");
+		expect(webFetch).toBeDefined();
+		expect(webFetch!.filePath).toBe(userSkillPath);
+		expect(webFetch!.description).toBe("User web-fetch override");
+	});
+
+	it("project auto-discovered skill should override package skill with same name", async () => {
+		const pkgDir = createPackageWithSkill("web-fetch", "Package web-fetch skill");
+		const projectSkillPath = createProjectSkill("web-fetch", "Project web-fetch override");
+		createSettingsWithPackage(pkgDir, "user");
+
+		const loader = new DefaultResourceLoader({ cwd, agentDir });
+		await loader.reload();
+
+		const { skills } = loader.getSkills();
+		const webFetch = skills.find((s) => s.name === "web-fetch");
+		expect(webFetch).toBeDefined();
+		expect(webFetch!.filePath).toBe(projectSkillPath);
+		expect(webFetch!.description).toBe("Project web-fetch override");
+	});
+
+	it("project skill should override user skill which should override package skill", async () => {
+		const pkgDir = createPackageWithSkill("web-fetch", "Package web-fetch skill");
+		createUserSkill("web-fetch", "User web-fetch override");
+		const projectSkillPath = createProjectSkill("web-fetch", "Project web-fetch override");
+		createSettingsWithPackage(pkgDir, "user");
+
+		const loader = new DefaultResourceLoader({ cwd, agentDir });
+		await loader.reload();
+
+		const { skills } = loader.getSkills();
+		const webFetch = skills.find((s) => s.name === "web-fetch");
+		expect(webFetch).toBeDefined();
+		expect(webFetch!.filePath).toBe(projectSkillPath);
+		expect(webFetch!.description).toBe("Project web-fetch override");
+	});
+
+	it("collision diagnostics should report package skill as loser when user skill wins", async () => {
+		const pkgDir = createPackageWithSkill("web-fetch", "Package web-fetch skill");
+		createUserSkill("web-fetch", "User web-fetch override");
+		createSettingsWithPackage(pkgDir, "user");
+
+		const loader = new DefaultResourceLoader({ cwd, agentDir });
+		await loader.reload();
+
+		const { diagnostics } = loader.getSkills();
+		const collision = diagnostics.find((d) => d.type === "collision" && d.collision?.name === "web-fetch");
+		expect(collision).toBeDefined();
+		expect(collision!.collision!.loserPath).toContain("fake-package");
+	});
+});

packages/coding-agent/test/suite/regressions/2791-fswatch-error-crash.test.ts

@@ -0,0 +1,106 @@
+import { execFileSync } from "node:child_process";
+import { mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+
+/**
+ * Regression test for https://github.com/earendil-works/pi-mono/issues/2791
+ *
+ * fs.watch() returns an FSWatcher (EventEmitter). If the watcher emits an
+ * 'error' event after creation and no error handler is attached, Node.js
+ * treats it as an uncaught exception and terminates the process.
+ *
+ * We test this by spawning a child process that:
+ * 1. Sets up a custom theme with the watcher enabled
+ * 2. Finds the FSWatcher via process._getActiveHandles()
+ * 3. Emits a synthetic 'error' event on it
+ * 4. If the watcher has no error handler -> crash (exit != 0) -> bug present
+ * 5. If the watcher has an error handler -> clean exit (exit 0) -> bug fixed
+ */
+describe("issue #2791 fs.watch error event crashes process", () => {
+	let tempRoot: string;
+
+	beforeEach(() => {
+		tempRoot = mkdtempSync(join(tmpdir(), "pi-2791-"));
+		const agentDir = join(tempRoot, "agent");
+		const themesDir = join(agentDir, "themes");
+		mkdirSync(themesDir, { recursive: true });
+
+		// Copy dark.json as "custom-test" theme
+		const darkThemePath = join(__dirname, "../../../src/modes/interactive/theme/dark.json");
+		const darkTheme = JSON.parse(readFileSync(darkThemePath, "utf-8"));
+		darkTheme.name = "custom-test";
+		writeFileSync(join(themesDir, "custom-test.json"), JSON.stringify(darkTheme, null, 2));
+	});
+
+	afterEach(() => {
+		rmSync(tempRoot, { recursive: true, force: true });
+	});
+
+	it("process should survive an error event on the theme FSWatcher", () => {
+		const themeModulePath = join(__dirname, "../../../src/modes/interactive/theme/theme.ts").replace(/\\/g, "/");
+		const agentDir = join(tempRoot, "agent").replace(/\\/g, "/");
+
+		// Script that sets up the watcher and emits a synthetic error on it.
+		// If no .on('error') handler is attached, EventEmitter.emit('error')
+		// throws, which either crashes the process or gets caught by our try/catch.
+		const scriptPath = join(tempRoot, "test-watcher-error.mts");
+		writeFileSync(
+			scriptPath,
+			`
+import { setTheme, stopThemeWatcher } from "${themeModulePath}";
+
+process.env.PI_CODING_AGENT_DIR = "${agentDir}";
+
+setTheme("custom-test", true);
+
+// Find the FSWatcher among active handles
+const handles = (process as any)._getActiveHandles();
+const fsWatcher = handles.find((h: any) => h.constructor?.name === "FSWatcher");
+
+if (!fsWatcher) {
+	process.stderr.write("no FSWatcher found among active handles\\n");
+	process.exit(2);
+}
+
+const errorListenerCount = fsWatcher.listenerCount("error");
+if (errorListenerCount === 0) {
+	process.stderr.write("BUG: FSWatcher has no error handler (issue #2791)\\n");
+}
+
+// Emitting 'error' on an EventEmitter with no error listener throws.
+// This simulates an async OS error (e.g. ReadDirectoryChangesW invalidation).
+try {
+	fsWatcher.emit("error", new Error("simulated OS watcher failure"));
+} catch {
+	process.stderr.write("error event was unhandled and threw\\n");
+	process.exit(1);
+}
+
+stopThemeWatcher();
+process.exit(0);
+`,
+		);
+
+		let _stdout = "";
+		let stderr = "";
+		let exitCode: number;
+		try {
+			_stdout = execFileSync(process.execPath, [scriptPath], {
+				timeout: 10000,
+				encoding: "utf-8",
+				env: { ...process.env, PI_CODING_AGENT_DIR: agentDir },
+				stdio: ["pipe", "pipe", "pipe"],
+			});
+			exitCode = 0;
+		} catch (err: unknown) {
+			const e = err as { status: number; stdout: string; stderr: string };
+			_stdout = e.stdout ?? "";
+			stderr = e.stderr ?? "";
+			exitCode = e.status ?? 1;
+		}
+
+		expect(exitCode, `Child crashed (exit ${exitCode}). stderr: ${stderr.trim()}`).toBe(0);
+	});
+});

packages/coding-agent/test/suite/regressions/2835-tools-allowlist-filters-extension-tools.test.ts

@@ -0,0 +1,94 @@
+import { existsSync, mkdirSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { getModel } from "@earendil-works/pi-ai/compat";
+import { Type } from "typebox";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { DefaultResourceLoader } from "../../../src/core/resource-loader.ts";
+import { createAgentSession } from "../../../src/core/sdk.ts";
+import { SessionManager } from "../../../src/core/session-manager.ts";
+import { SettingsManager } from "../../../src/core/settings-manager.ts";
+
+describe("regression #2835: tool allowlists filter extension tools", () => {
+	let tempDir: string;
+	let agentDir: string;
+
+	beforeEach(() => {
+		tempDir = join(tmpdir(), `pi-tools-filter-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		agentDir = join(tempDir, "agent");
+		mkdirSync(agentDir, { recursive: true });
+	});
+
+	afterEach(() => {
+		if (tempDir && existsSync(tempDir)) {
+			rmSync(tempDir, { recursive: true, force: true });
+		}
+	});
+
+	async function createSession(allowedToolNames?: string[]) {
+		const settingsManager = SettingsManager.create(tempDir, agentDir);
+		const sessionManager = SessionManager.inMemory(tempDir);
+		const resourceLoader = new DefaultResourceLoader({
+			cwd: tempDir,
+			agentDir,
+			settingsManager,
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_start", () => {
+						pi.registerTool({
+							name: "dynamic_tool",
+							label: "Dynamic Tool",
+							description: "Tool registered from session_start",
+							promptSnippet: "Run dynamic test behavior",
+							parameters: Type.Object({}),
+							execute: async () => ({
+								content: [{ type: "text", text: "ok" }],
+								details: {},
+							}),
+						});
+					});
+				},
+			],
+		});
+		await resourceLoader.reload();
+
+		const { session } = await createAgentSession({
+			cwd: tempDir,
+			agentDir,
+			model: getModel("anthropic", "claude-sonnet-4-5")!,
+			settingsManager,
+			sessionManager,
+			resourceLoader,
+			tools: allowedToolNames,
+		});
+		await session.bindExtensions({});
+		return session;
+	}
+
+	it("allows only explicitly listed built-in and extension tools", async () => {
+		const session = await createSession(["read", "dynamic_tool"]);
+
+		expect(
+			session
+				.getAllTools()
+				.map((tool) => tool.name)
+				.sort(),
+		).toEqual(["dynamic_tool", "read"]);
+		expect(session.getActiveToolNames().sort()).toEqual(["dynamic_tool", "read"]);
+		expect(session.systemPrompt).toContain("- read: Read file contents");
+		expect(session.systemPrompt).toContain("- dynamic_tool: Run dynamic test behavior");
+		expect(session.systemPrompt).not.toContain("- bash:");
+		expect(session.systemPrompt).not.toContain("- edit:");
+		session.dispose();
+	});
+
+	it("disables all tools when the allowlist is empty", async () => {
+		const session = await createSession([]);
+
+		expect(session.getAllTools()).toEqual([]);
+		expect(session.getActiveToolNames()).toEqual([]);
+		expect(session.systemPrompt).toContain("Available tools:\n(none)");
+		expect(session.systemPrompt).not.toContain("dynamic_tool");
+		session.dispose();
+	});
+});

packages/coding-agent/test/suite/regressions/2860-replaced-session-context.test.ts

@@ -0,0 +1,279 @@
+import { existsSync, mkdirSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { fauxAssistantMessage, registerFauxProvider } from "@earendil-works/pi-ai/compat";
+import { afterEach, describe, expect, it } from "vitest";
+import type { AgentSession } from "../../../src/core/agent-session.ts";
+import {
+	type CreateAgentSessionRuntimeFactory,
+	createAgentSessionFromServices,
+	createAgentSessionRuntime,
+	createAgentSessionServices,
+} from "../../../src/core/agent-session-runtime.ts";
+import { AuthStorage } from "../../../src/core/auth-storage.ts";
+import { ModelRuntime } from "../../../src/core/model-runtime.ts";
+import { SessionManager } from "../../../src/core/session-manager.ts";
+import type { ExtensionAPI, ExtensionCommandContext, ExtensionFactory } from "../../../src/index.ts";
+
+function getText(message: AgentSession["messages"][number]): string {
+	if (!("content" in message)) {
+		return "";
+	}
+	return typeof message.content === "string"
+		? message.content
+		: message.content
+				.filter((part): part is { type: "text"; text: string } => part.type === "text")
+				.map((part) => part.text)
+				.join("");
+}
+
+describe("regression #2860: replaced session callbacks", () => {
+	const cleanups: Array<() => Promise<void> | void> = [];
+
+	afterEach(async () => {
+		while (cleanups.length > 0) {
+			await cleanups.pop()?.();
+		}
+	});
+
+	async function createRuntimeForTest(extensionFactory: ExtensionFactory, responses: string[]) {
+		const tempDir = join(tmpdir(), `pi-2860-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		mkdirSync(tempDir, { recursive: true });
+
+		const faux = registerFauxProvider({
+			models: [{ id: "faux-1", reasoning: false }],
+		});
+		faux.setResponses(responses.map((response) => fauxAssistantMessage(response)));
+
+		const authStorage = AuthStorage.inMemory();
+		await authStorage.modify(faux.getModel().provider, async () => ({ type: "api_key", key: "faux-key" }));
+		const modelRuntime = await ModelRuntime.create({
+			credentials: authStorage,
+			modelsPath: join(tempDir, "models.json"),
+		});
+
+		const createRuntime: CreateAgentSessionRuntimeFactory = async ({ cwd, sessionManager, sessionStartEvent }) => {
+			const services = await createAgentSessionServices({
+				cwd,
+				agentDir: tempDir,
+				modelRuntime,
+				resourceLoaderOptions: {
+					extensionFactories: [
+						(pi: ExtensionAPI) => {
+							pi.registerProvider(faux.getModel().provider, {
+								baseUrl: faux.getModel().baseUrl,
+								apiKey: "faux-key",
+								api: faux.api,
+								models: faux.models.map((registeredModel) => ({
+									id: registeredModel.id,
+									name: registeredModel.name,
+									api: registeredModel.api,
+									reasoning: registeredModel.reasoning,
+									input: registeredModel.input,
+									cost: registeredModel.cost,
+									contextWindow: registeredModel.contextWindow,
+									maxTokens: registeredModel.maxTokens,
+								})),
+							});
+							extensionFactory(pi);
+						},
+					],
+					noSkills: true,
+					noPromptTemplates: true,
+					noThemes: true,
+				},
+			});
+			return {
+				...(await createAgentSessionFromServices({
+					services,
+					sessionManager,
+					sessionStartEvent,
+					model: faux.getModel(),
+				})),
+				services,
+				diagnostics: services.diagnostics,
+			};
+		};
+
+		const runtime = await createAgentSessionRuntime(createRuntime, {
+			cwd: tempDir,
+			agentDir: tempDir,
+			sessionManager: SessionManager.create(tempDir),
+		});
+
+		const rebindSession = async (): Promise<void> => {
+			const session = runtime.session;
+			await session.bindExtensions({
+				commandContextActions: {
+					waitForIdle: () => session.agent.waitForIdle(),
+					newSession: async (options) => runtime.newSession(options),
+					fork: async (entryId, options) => {
+						const result = await runtime.fork(entryId, options);
+						return { cancelled: result.cancelled };
+					},
+					navigateTree: async (targetId, options) => {
+						const result = await session.navigateTree(targetId, {
+							summarize: options?.summarize,
+							customInstructions: options?.customInstructions,
+							replaceInstructions: options?.replaceInstructions,
+							label: options?.label,
+						});
+						return { cancelled: result.cancelled };
+					},
+					switchSession: async (sessionPath, options) => runtime.switchSession(sessionPath, options),
+					reload: async () => {
+						await session.reload();
+					},
+				},
+			});
+		};
+
+		runtime.setRebindSession(async () => {
+			await rebindSession();
+		});
+		await rebindSession();
+
+		cleanups.push(async () => {
+			await runtime.dispose();
+			faux.unregister();
+			if (existsSync(tempDir)) {
+				rmSync(tempDir, { recursive: true, force: true });
+			}
+		});
+
+		return { runtime, faux };
+	}
+
+	it("rebinds before withSession, targets the replacement session, and invalidates stale pi/ctx", async () => {
+		const events: string[] = [];
+		let oldCtx: ExtensionCommandContext | undefined;
+		let oldPi: ExtensionAPI | undefined;
+		let oldSessionFile: string | undefined;
+		let staleCtxThrows = false;
+		let stalePiThrows = false;
+		let replacementSessionFile: string | undefined;
+		let instanceId = 0;
+		const { runtime } = await createRuntimeForTest(
+			(pi) => {
+				const currentInstance = ++instanceId;
+				pi.on("session_start", () => {
+					events.push(`start:${currentInstance}`);
+				});
+				pi.on("session_shutdown", () => {
+					events.push(`shutdown:${currentInstance}`);
+				});
+				pi.registerCommand("repro", {
+					description: "repro",
+					handler: async (_args, ctx) => {
+						oldCtx = ctx;
+						oldPi = pi;
+						oldSessionFile = ctx.sessionManager.getSessionFile();
+						await ctx.newSession({
+							parentSession: oldSessionFile,
+							withSession: async (replacedCtx) => {
+								events.push(`with:${currentInstance}`);
+								replacementSessionFile = replacedCtx.sessionManager.getSessionFile();
+								try {
+									oldCtx?.sessionManager.getSessionFile();
+								} catch {
+									staleCtxThrows = true;
+								}
+								try {
+									oldPi?.sendUserMessage("stale message");
+								} catch {
+									stalePiThrows = true;
+								}
+								await replacedCtx.sendUserMessage("Hello from the new session!");
+							},
+						});
+					},
+				});
+			},
+			["hello reply"],
+		);
+
+		expect(events).toEqual(["start:1"]);
+
+		await runtime.session.prompt("/repro");
+
+		expect(events).toEqual(["start:1", "shutdown:1", "start:2", "with:1"]);
+		expect(replacementSessionFile).toBeDefined();
+		expect(replacementSessionFile).not.toBe(oldSessionFile);
+		expect(staleCtxThrows).toBe(true);
+		expect(stalePiThrows).toBe(true);
+		expect(runtime.session.messages.map((message) => `${message.role}:${getText(message)}`)).toEqual([
+			"user:Hello from the new session!",
+			"assistant:hello reply",
+		]);
+	});
+
+	it("supports withSession for fork", async () => {
+		const { runtime } = await createRuntimeForTest(
+			(pi) => {
+				pi.registerCommand("fork-it", {
+					description: "fork-it",
+					handler: async (_args, ctx) => {
+						const leafId = ctx.sessionManager.getLeafId();
+						if (!leafId) {
+							throw new Error("Missing leaf id");
+						}
+						await ctx.fork(leafId, {
+							position: "at",
+							withSession: async (replacedCtx) => {
+								await replacedCtx.sendUserMessage("fork callback message");
+							},
+						});
+					},
+				});
+			},
+			["seed reply", "fork reply"],
+		);
+
+		await runtime.session.prompt("seed");
+		await runtime.session.prompt("/fork-it");
+
+		expect(runtime.session.messages.map((message) => `${message.role}:${getText(message)}`)).toEqual([
+			"user:seed",
+			"assistant:seed reply",
+			"user:fork callback message",
+			"assistant:fork reply",
+		]);
+	});
+
+	it("supports withSession for switchSession", async () => {
+		let targetSessionPath = "";
+		const { runtime } = await createRuntimeForTest(
+			(pi) => {
+				pi.registerCommand("switch-it", {
+					description: "switch-it",
+					handler: async (_args, ctx) => {
+						await ctx.switchSession(targetSessionPath, {
+							withSession: async (replacedCtx) => {
+								await replacedCtx.sendUserMessage("switch callback message");
+							},
+						});
+					},
+				});
+			},
+			["root reply", "target reply", "switch reply"],
+		);
+
+		await runtime.session.prompt("root");
+		const originalSessionPath = runtime.session.sessionFile;
+		const newSessionResult = await runtime.newSession();
+		expect(newSessionResult.cancelled).toBe(false);
+		await runtime.session.prompt("target");
+		targetSessionPath = runtime.session.sessionFile!;
+		await runtime.switchSession(originalSessionPath!);
+
+		await runtime.session.prompt("/switch-it");
+
+		expect(runtime.session.sessionFile).toBe(targetSessionPath);
+		expect(runtime.session.messages.map((message) => `${message.role}:${getText(message)}`)).toEqual([
+			"user:target",
+			"assistant:target reply",
+			"user:switch callback message",
+			"assistant:switch reply",
+		]);
+	});
+});

packages/coding-agent/test/suite/regressions/3217-scoped-model-order.test.ts

@@ -0,0 +1,103 @@
+import { setKeybindings, type TUI } from "@earendil-works/pi-tui";
+import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+import { KeybindingsManager } from "../../../src/core/keybindings.ts";
+import { ModelSelectorComponent } from "../../../src/modes/interactive/components/model-selector.ts";
+import { ScopedModelsSelectorComponent } from "../../../src/modes/interactive/components/scoped-models-selector.ts";
+import { initTheme } from "../../../src/modes/interactive/theme/theme.ts";
+import { stripAnsi } from "../../../src/utils/ansi.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+function createFakeTui(): TUI {
+	return {
+		requestRender: () => {},
+	} as unknown as TUI;
+}
+
+describe("issue #3217 scoped model ordering", () => {
+	const harnesses: Harness[] = [];
+
+	beforeAll(() => {
+		initTheme("dark");
+	});
+
+	beforeEach(() => {
+		// Ensure test isolation: keybindings are a global singleton
+		setKeybindings(new KeybindingsManager());
+	});
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("propagates reordered scoped models back to the session state", async () => {
+		const harness = await createHarness({
+			models: [
+				{ id: "faux-1", name: "One", reasoning: true },
+				{ id: "faux-2", name: "Two", reasoning: true },
+				{ id: "faux-3", name: "Three", reasoning: true },
+			],
+		});
+		harnesses.push(harness);
+
+		const orderedIds = harness.models.map((model) => `${model.provider}/${model.id}`);
+		const changes: Array<string[] | null> = [];
+		const selector = new ScopedModelsSelectorComponent(
+			{
+				allModels: [...harness.models],
+				enabledModelIds: orderedIds,
+			},
+			{
+				onChange: (enabledModelIds) => {
+					changes.push(enabledModelIds);
+				},
+				onPersist: () => {},
+				onCancel: () => {},
+			},
+		);
+
+		selector.handleInput("\x1b[1;3B");
+
+		expect(changes).toEqual([[orderedIds[1], orderedIds[0], orderedIds[2]]]);
+	});
+
+	it("preserves scoped model order in the /model scoped tab", async () => {
+		const harness = await createHarness({
+			models: [
+				{ id: "faux-1", name: "One", reasoning: true },
+				{ id: "faux-2", name: "Two", reasoning: true },
+				{ id: "faux-3", name: "Three", reasoning: true },
+			],
+		});
+		harnesses.push(harness);
+
+		const modelOne = harness.getModel("faux-1")!;
+		const modelTwo = harness.getModel("faux-2")!;
+		const modelThree = harness.getModel("faux-3")!;
+		const selector = new ModelSelectorComponent(
+			createFakeTui(),
+			modelOne,
+			harness.session.modelRuntime,
+			[{ model: modelTwo }, { model: modelOne }, { model: modelThree }],
+			() => {},
+			() => {},
+		);
+
+		await vi.waitFor(() => {
+			const rendered = stripAnsi(selector.render(120).join("\n"));
+			expect(rendered).toContain(`[${modelOne.provider}]`);
+			expect(rendered).toContain("Model catalogs refreshed.");
+		});
+
+		const renderedLines = stripAnsi(selector.render(120).join("\n"))
+			.split("\n")
+			.filter((line) => line.includes(`[${modelOne.provider}]`));
+		const orderedIds = renderedLines.slice(0, 3).map((line) => {
+			const [modelId] = line.trim().replace(/^→\s*/, "").split(" [");
+			return modelId?.replace(/^✓\s*/, "").trim() ?? "";
+		});
+
+		expect(orderedIds).toEqual([modelTwo.id, modelOne.id, modelThree.id]);
+	});
+});

packages/coding-agent/test/suite/regressions/3302-find-path-glob.test.ts

@@ -0,0 +1,72 @@
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { createFindToolDefinition } from "../../../src/core/tools/find.ts";
+
+/**
+ * Regression test for https://github.com/earendil-works/pi-mono/issues/3302
+ *
+ * The `find` tool advertises glob patterns like `src/**\/*.spec.ts`, but the
+ * default fd-backed implementation used `fd --glob <pattern>` without
+ * `--full-path`, which makes fd match only against the basename. Any pattern
+ * containing a `/` therefore silently returned no matches.
+ *
+ * The fix switches fd into full-path mode when the pattern contains a `/`
+ * and prepends `**\/` so the pattern can match against the absolute candidate
+ * path that fd feeds to the matcher.
+ */
+describe("issue #3302 find returns no results for path-based glob patterns", () => {
+	let tempRoot: string;
+
+	beforeEach(() => {
+		tempRoot = mkdtempSync(join(tmpdir(), "pi-3302-"));
+		mkdirSync(join(tempRoot, "some", "parent", "child"), { recursive: true });
+		mkdirSync(join(tempRoot, "src", "foo", "bar"), { recursive: true });
+		writeFileSync(join(tempRoot, "some", "parent", "child", "file.ext"), "");
+		writeFileSync(join(tempRoot, "some", "parent", "child", "test.spec.ts"), "");
+		writeFileSync(join(tempRoot, "src", "foo", "bar", "example.spec.ts"), "");
+	});
+
+	afterEach(() => {
+		rmSync(tempRoot, { recursive: true, force: true });
+	});
+
+	async function runFind(pattern: string): Promise<string[]> {
+		const def = createFindToolDefinition(tempRoot);
+		// The find tool implementation does not touch ctx; pass a minimal stub.
+		const ctx = {} as Parameters<typeof def.execute>[4];
+		const result = (await def.execute("call-1", { pattern }, undefined, undefined, ctx)) as {
+			content: Array<{ type: string; text?: string }>;
+		};
+		const text = result.content[0]?.text ?? "";
+		if (text === "No files found matching pattern") return [];
+		return text
+			.split("\n")
+			.map((l) => l.trim())
+			.filter((l) => l.length > 0 && !l.startsWith("["));
+	}
+
+	it("basename pattern still matches (regression-safe)", async () => {
+		const files = await runFind("*.spec.ts");
+		expect(files.sort()).toEqual(["some/parent/child/test.spec.ts", "src/foo/bar/example.spec.ts"]);
+	});
+
+	it("directory-prefixed pattern with ** tail matches subtree", async () => {
+		const files = await runFind("some/parent/child/**");
+		// Matches files (and possibly directories) under the subtree. Assert the two files are present.
+		expect(files).toContain("some/parent/child/file.ext");
+		expect(files).toContain("some/parent/child/test.spec.ts");
+	});
+
+	it("leading ** wildcard with path segments matches", async () => {
+		const files = await runFind("**/parent/child/*");
+		expect(files.sort()).toContain("some/parent/child/file.ext");
+		expect(files.sort()).toContain("some/parent/child/test.spec.ts");
+	});
+
+	it("src/**/*.spec.ts matches nested spec file", async () => {
+		const files = await runFind("src/**/*.spec.ts");
+		expect(files).toEqual(["src/foo/bar/example.spec.ts"]);
+	});
+});

packages/coding-agent/test/suite/regressions/3303-find-nested-gitignore.test.ts

@@ -0,0 +1,83 @@
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { createFindToolDefinition } from "../../../src/core/tools/find.ts";
+
+/**
+ * Regression test for https://github.com/earendil-works/pi-mono/issues/3303
+ *
+ * The `find` tool previously collected every `.gitignore` under the search
+ * path and passed them to `fd` via `--ignore-file`. fd treats `--ignore-file`
+ * entries as a single global ignore source, so rules from `a/.gitignore`
+ * also filtered files under sibling `b/`. The fix switches to fd's
+ * hierarchical `.gitignore` handling via `--no-require-git` and drops the
+ * manual collection.
+ */
+describe("issue #3303 nested .gitignore rules leak into sibling directories", () => {
+	let tempRoot: string;
+
+	async function runFind(pattern: string): Promise<string[]> {
+		const def = createFindToolDefinition(tempRoot);
+		const ctx = {} as Parameters<typeof def.execute>[4];
+		const result = (await def.execute("call-1", { pattern }, undefined, undefined, ctx)) as {
+			content: Array<{ type: string; text?: string }>;
+		};
+		const text = result.content[0]?.text ?? "";
+		if (text === "No files found matching pattern") return [];
+		return text
+			.split("\n")
+			.map((l) => l.trim())
+			.filter((l) => l.length > 0 && !l.startsWith("["))
+			.sort();
+	}
+
+	afterEach(() => {
+		if (tempRoot) rmSync(tempRoot, { recursive: true, force: true });
+	});
+
+	describe("flat sibling case", () => {
+		beforeEach(() => {
+			tempRoot = mkdtempSync(join(tmpdir(), "pi-3303-flat-"));
+			mkdirSync(join(tempRoot, "a"), { recursive: true });
+			mkdirSync(join(tempRoot, "b"), { recursive: true });
+			writeFileSync(join(tempRoot, "a", ".gitignore"), "ignored.txt\n");
+			writeFileSync(join(tempRoot, "a", "ignored.txt"), "");
+			writeFileSync(join(tempRoot, "a", "kept.txt"), "");
+			writeFileSync(join(tempRoot, "b", "ignored.txt"), "");
+			writeFileSync(join(tempRoot, "b", "kept.txt"), "");
+			writeFileSync(join(tempRoot, "root.txt"), "");
+		});
+
+		it("applies a/.gitignore only inside a/ and leaves b/ untouched", async () => {
+			const files = await runFind("**/*.txt");
+			expect(files).toEqual(["a/kept.txt", "b/ignored.txt", "b/kept.txt", "root.txt"]);
+		});
+	});
+
+	describe("deeply nested case", () => {
+		beforeEach(() => {
+			tempRoot = mkdtempSync(join(tmpdir(), "pi-3303-deep-"));
+			mkdirSync(join(tempRoot, "a", "deep"), { recursive: true });
+			mkdirSync(join(tempRoot, "b"), { recursive: true });
+			writeFileSync(join(tempRoot, "a", ".gitignore"), "ignored.txt\n");
+			writeFileSync(join(tempRoot, "a", "deep", ".gitignore"), "secret.txt\n");
+			writeFileSync(join(tempRoot, "a", "ignored.txt"), "");
+			writeFileSync(join(tempRoot, "a", "kept.txt"), "");
+			writeFileSync(join(tempRoot, "a", "deep", "ignored.txt"), "");
+			writeFileSync(join(tempRoot, "a", "deep", "secret.txt"), "");
+			writeFileSync(join(tempRoot, "a", "deep", "kept.txt"), "");
+			writeFileSync(join(tempRoot, "b", "ignored.txt"), "");
+			writeFileSync(join(tempRoot, "b", "kept.txt"), "");
+			writeFileSync(join(tempRoot, "root.txt"), "");
+		});
+
+		it("scopes each .gitignore to its own subtree", async () => {
+			const files = await runFind("**/*.txt");
+			// a/.gitignore ignores 'ignored.txt' within a/ and a/deep/.
+			// a/deep/.gitignore additionally ignores 'secret.txt' within a/deep/.
+			// b/ is untouched by either.
+			expect(files).toEqual(["a/deep/kept.txt", "a/kept.txt", "b/ignored.txt", "b/kept.txt", "root.txt"]);
+		});
+	});
+});

packages/coding-agent/test/suite/regressions/3317-network-connection-lost-retry.test.ts

@@ -0,0 +1,33 @@
+import { fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, getAssistantTexts, type Harness } from "../harness.ts";
+
+describe("issue #3317 network connection lost retry", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it('retries transient "Network connection lost." failures', async () => {
+		const harness = await createHarness({
+			settings: { retry: { enabled: true, maxRetries: 3, baseDelayMs: 1 } },
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage("", { stopReason: "error", errorMessage: "Network connection lost." }),
+			fauxAssistantMessage("recovered after reconnect"),
+		]);
+
+		await harness.session.prompt("test");
+
+		expect(harness.faux.state.callCount).toBe(2);
+		expect(harness.eventsOfType("auto_retry_start").map((event) => event.errorMessage)).toEqual([
+			"Network connection lost.",
+		]);
+		expect(harness.eventsOfType("auto_retry_end").map((event) => event.success)).toEqual([true]);
+		expect(getAssistantTexts(harness)).toContain("recovered after reconnect");
+	});
+});

packages/coding-agent/test/suite/regressions/3592-no-builtin-tools-keeps-extension-tools.test.ts

@@ -0,0 +1,119 @@
+import { existsSync, mkdirSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { getModel } from "@earendil-works/pi-ai/compat";
+import { Type } from "typebox";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import {
+	createAgentSessionFromServices,
+	createAgentSessionServices,
+} from "../../../src/core/agent-session-services.ts";
+import { DefaultResourceLoader } from "../../../src/core/resource-loader.ts";
+import { createAgentSession } from "../../../src/core/sdk.ts";
+import { SessionManager } from "../../../src/core/session-manager.ts";
+import { SettingsManager } from "../../../src/core/settings-manager.ts";
+
+describe("regression #3592: no-builtin-tools keeps extension tools enabled", () => {
+	let tempDir: string;
+	let agentDir: string;
+
+	beforeEach(() => {
+		tempDir = join(tmpdir(), `pi-no-builtin-tools-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		agentDir = join(tempDir, "agent");
+		mkdirSync(agentDir, { recursive: true });
+	});
+
+	afterEach(() => {
+		if (tempDir && existsSync(tempDir)) {
+			rmSync(tempDir, { recursive: true, force: true });
+		}
+	});
+
+	async function createSession(options?: { noTools?: "all" | "builtin"; tools?: string[] }) {
+		const settingsManager = SettingsManager.create(tempDir, agentDir);
+		const sessionManager = SessionManager.inMemory(tempDir);
+		const resourceLoader = new DefaultResourceLoader({
+			cwd: tempDir,
+			agentDir,
+			settingsManager,
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_start", () => {
+						pi.registerTool({
+							name: "dynamic_tool",
+							label: "Dynamic Tool",
+							description: "Tool registered from session_start",
+							promptSnippet: "Run dynamic test behavior",
+							parameters: Type.Object({}),
+							execute: async () => ({
+								content: [{ type: "text", text: "ok" }],
+								details: {},
+							}),
+						});
+					});
+				},
+			],
+		});
+		await resourceLoader.reload();
+
+		const { session } = await createAgentSession({
+			cwd: tempDir,
+			agentDir,
+			model: getModel("anthropic", "claude-sonnet-4-5")!,
+			settingsManager,
+			sessionManager,
+			resourceLoader,
+			noTools: options?.noTools,
+			tools: options?.tools,
+		});
+		await session.bindExtensions({});
+		return session;
+	}
+
+	it("keeps extension tools active when built-in defaults are disabled", async () => {
+		const session = await createSession({ noTools: "builtin" });
+
+		expect(
+			session
+				.getAllTools()
+				.map((tool) => tool.name)
+				.sort(),
+		).toEqual(["bash", "dynamic_tool", "edit", "find", "grep", "ls", "powershell", "read", "write"]);
+		expect(session.getActiveToolNames()).toEqual(["dynamic_tool"]);
+		expect(session.systemPrompt).toContain("- dynamic_tool: Run dynamic test behavior");
+		expect(session.systemPrompt).not.toContain("- read:");
+		expect(session.systemPrompt).not.toContain("- bash:");
+		session.dispose();
+	});
+
+	it("still disables all tools when noTools is all", async () => {
+		const session = await createSession({ noTools: "all" });
+
+		expect(session.getAllTools()).toEqual([]);
+		expect(session.getActiveToolNames()).toEqual([]);
+		expect(session.systemPrompt).toContain("Available tools:\n(none)");
+		session.dispose();
+	});
+
+	it("propagates noTools through service-based session creation", async () => {
+		const settingsManager = SettingsManager.create(tempDir, agentDir);
+		const sessionManager = SessionManager.inMemory(tempDir);
+		const services = await createAgentSessionServices({
+			cwd: tempDir,
+			agentDir,
+			settingsManager,
+		});
+
+		const { session } = await createAgentSessionFromServices({
+			services,
+			sessionManager,
+			model: getModel("anthropic", "claude-sonnet-4-5")!,
+			noTools: "builtin",
+		});
+
+		expect(session.getActiveToolNames()).toEqual([]);
+		expect(session.systemPrompt).toContain("Available tools:\n(none)");
+		expect(session.systemPrompt).not.toContain("- read:");
+		session.dispose();
+	});
+});

packages/coding-agent/test/suite/regressions/3616-settings-inmemory-reload.test.ts

@@ -0,0 +1,86 @@
+import { existsSync, mkdirSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { DefaultResourceLoader } from "../../../src/core/resource-loader.ts";
+import { SettingsManager } from "../../../src/core/settings-manager.ts";
+
+describe("regression #3616: in-memory settings survive reload", () => {
+	let tempDir: string;
+	let agentDir: string;
+
+	beforeEach(() => {
+		tempDir = join(tmpdir(), `pi-settings-inmemory-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		agentDir = join(tempDir, "agent");
+		mkdirSync(agentDir, { recursive: true });
+	});
+
+	afterEach(() => {
+		if (tempDir && existsSync(tempDir)) {
+			rmSync(tempDir, { recursive: true, force: true });
+		}
+	});
+
+	it("preserves initial settings after direct reload", async () => {
+		const settingsManager = SettingsManager.inMemory({
+			defaultThinkingLevel: "high",
+			images: { autoResize: false },
+			compaction: { enabled: false },
+		});
+
+		await settingsManager.reload();
+
+		expect(settingsManager.getDefaultThinkingLevel()).toBe("high");
+		expect(settingsManager.getImageAutoResize()).toBe(false);
+		expect(settingsManager.getCompactionEnabled()).toBe(false);
+		expect(settingsManager.getGlobalSettings()).toEqual({
+			defaultThinkingLevel: "high",
+			images: { autoResize: false },
+			compaction: { enabled: false },
+		});
+	});
+
+	it("preserves initial settings when DefaultResourceLoader reloads", async () => {
+		const settingsManager = SettingsManager.inMemory({
+			defaultThinkingLevel: "high",
+			images: { autoResize: false },
+			compaction: { enabled: false },
+		});
+		const resourceLoader = new DefaultResourceLoader({
+			cwd: tempDir,
+			agentDir,
+			settingsManager,
+			noExtensions: true,
+			noSkills: true,
+			noPromptTemplates: true,
+			noThemes: true,
+			noContextFiles: true,
+		});
+
+		await resourceLoader.reload();
+
+		expect(settingsManager.getDefaultThinkingLevel()).toBe("high");
+		expect(settingsManager.getImageAutoResize()).toBe(false);
+		expect(settingsManager.getCompactionEnabled()).toBe(false);
+	});
+
+	it("preserves initial settings after an unrelated setter, flush, and reload", async () => {
+		const settingsManager = SettingsManager.inMemory({
+			images: { autoResize: false },
+			compaction: { enabled: false },
+		});
+
+		settingsManager.setTheme("dark");
+		await settingsManager.flush();
+		await settingsManager.reload();
+
+		expect(settingsManager.getTheme()).toBe("dark");
+		expect(settingsManager.getImageAutoResize()).toBe(false);
+		expect(settingsManager.getCompactionEnabled()).toBe(false);
+		expect(settingsManager.getGlobalSettings()).toEqual({
+			images: { autoResize: false },
+			compaction: { enabled: false },
+			theme: "dark",
+		});
+	});
+});

packages/coding-agent/test/suite/regressions/3686-session-name-event.test.ts

@@ -0,0 +1,61 @@
+import { afterEach, describe, expect, it } from "vitest";
+import type { ExtensionAPI } from "../../../src/index.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+describe("regression #3686: session name changes emit an event", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("emits session_info_changed when AgentSession.setSessionName is called", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+
+		harness.session.setSessionName("hello world");
+
+		expect(harness.sessionManager.getSessionName()).toBe("hello world");
+		expect(harness.eventsOfType("session_info_changed").map((event) => event.name)).toEqual(["hello world"]);
+	});
+
+	it("emits session_info_changed when an extension calls pi.setSessionName", async () => {
+		let api: ExtensionAPI | undefined;
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					api = pi;
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		api?.setSessionName("from extension");
+
+		expect(harness.sessionManager.getSessionName()).toBe("from extension");
+		expect(harness.eventsOfType("session_info_changed").map((event) => event.name)).toEqual(["from extension"]);
+	});
+
+	it("emits session_info_changed to extensions", async () => {
+		let api: ExtensionAPI | undefined;
+		const events: Array<{ name: string | undefined }> = [];
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					api = pi;
+					pi.on("session_info_changed", (event) => {
+						events.push({ name: event.name });
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		api?.setSessionName("first");
+		harness.session.setSessionName("second");
+
+		expect(events).toEqual([{ name: "first" }, { name: "second" }]);
+	});
+});

packages/coding-agent/test/suite/regressions/3688-tree-cancel-compacting.test.ts

@@ -0,0 +1,36 @@
+import { afterEach, describe, expect, it } from "vitest";
+import { assistantMsg, userMsg } from "../../utilities.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+describe("issue #3688 tree cancellation compaction state", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("clears branch summary state when session_before_tree cancels navigation", async () => {
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_tree", () => ({ cancel: true }));
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		const targetId = harness.sessionManager.appendMessage(userMsg("first"));
+		harness.sessionManager.appendMessage(assistantMsg("reply"));
+		const currentLeafId = harness.sessionManager.appendMessage(userMsg("second"));
+
+		expect(harness.sessionManager.getLeafId()).toBe(currentLeafId);
+
+		const result = await harness.session.navigateTree(targetId, { summarize: false });
+
+		expect(result).toEqual({ cancelled: true });
+		expect(harness.session.isCompacting).toBe(false);
+		expect(harness.sessionManager.getLeafId()).toBe(currentLeafId);
+	});
+});

packages/coding-agent/test/suite/regressions/3982-message-end-cost-override.test.ts

@@ -0,0 +1,56 @@
+import { fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, type Harness } from "../harness.ts";
+
+describe("regression #3982: message_end cost override", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("allows extensions to replace finalized assistant usage cost", async () => {
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.on("message_end", (event) => {
+						if (event.message.role !== "assistant") return;
+
+						return {
+							message: {
+								...event.message,
+								usage: {
+									...event.message.usage,
+									cost: {
+										...event.message.usage.cost,
+										total: 0.123,
+									},
+								},
+							},
+						};
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("hello")]);
+
+		await harness.session.prompt("hi");
+
+		const assistantMessage = harness.session.messages.find((message) => message.role === "assistant");
+		expect(assistantMessage?.role).toBe("assistant");
+		if (assistantMessage?.role !== "assistant") {
+			throw new Error("missing assistant message");
+		}
+		expect(assistantMessage.usage.cost.total).toBe(0.123);
+
+		const messageEnd = harness.eventsOfType("message_end").find((event) => event.message.role === "assistant");
+		expect(messageEnd?.message.role).toBe("assistant");
+		if (messageEnd?.message.role !== "assistant") {
+			throw new Error("missing assistant message_end event");
+		}
+		expect(messageEnd.message.usage.cost.total).toBe(0.123);
+	});
+});

packages/coding-agent/test/suite/regressions/4167-thinking-toggle-pending-tool-render.test.ts

@@ -0,0 +1,184 @@
+import type { AgentMessage } from "@earendil-works/pi-agent-core";
+import type { AssistantMessage, ToolResultMessage, Usage } from "@earendil-works/pi-ai";
+import { Container, Text, type TUI } from "@earendil-works/pi-tui";
+import { beforeAll, describe, expect, test, vi } from "vitest";
+import type { AgentSessionEvent } from "../../../src/core/agent-session.ts";
+import type { SessionEntry } from "../../../src/core/session-manager.ts";
+import type { ToolExecutionComponent } from "../../../src/modes/interactive/components/tool-execution.ts";
+import { InteractiveMode } from "../../../src/modes/interactive/interactive-mode.ts";
+import { initTheme } from "../../../src/modes/interactive/theme/theme.ts";
+import { stripAnsi } from "../../../src/utils/ansi.ts";
+
+const TOOL_CALL_ID = "tool-4167";
+const TOOL_NAME = "slow_tool";
+
+const EMPTY_USAGE: Usage = {
+	input: 0,
+	output: 0,
+	cacheRead: 0,
+	cacheWrite: 0,
+	totalTokens: 0,
+	cost: {
+		input: 0,
+		output: 0,
+		cacheRead: 0,
+		cacheWrite: 0,
+		total: 0,
+	},
+};
+
+type RenderSessionItems = (
+	this: RenderSessionContextThis,
+	items: AgentMessage[],
+	options?: { updateFooter?: boolean; populateHistory?: boolean },
+) => void;
+
+type RenderSessionContextThis = {
+	pendingTools: Map<string, ToolExecutionComponent>;
+	chatContainer: Container;
+	footer: { invalidate(): void };
+	ui: TUI;
+	settingsManager: {
+		getShowImages(): boolean;
+		getImageWidthCells(): number;
+		getShowCacheMissNotices(): boolean;
+	};
+	sessionManager: { getCwd(): string; getEntries(): SessionEntry[] };
+	session: { retryAttempt: number; modelRegistry: { find(provider: string, modelId: string): undefined } };
+	toolOutputExpanded: boolean;
+	isInitialized: boolean;
+	updateEditorBorderColor(): void;
+	getRegisteredToolDefinition(toolName: string): undefined;
+	maybeShowAssistantDiagnostics(message: AssistantMessage): void;
+	addMessageToChat(message: AgentMessage, options?: { populateHistory?: boolean }): void;
+	renderSessionItems: RenderSessionItems;
+};
+
+type RenderSessionEntries = (
+	this: RenderSessionContextThis,
+	entries: SessionEntry[],
+	options?: { updateFooter?: boolean; populateHistory?: boolean },
+) => void;
+
+type HandleEvent = (this: RenderSessionContextThis, event: AgentSessionEvent) => Promise<void>;
+
+function createFakeInteractiveModeThis(): RenderSessionContextThis {
+	const chatContainer = new Container();
+	return {
+		pendingTools: new Map<string, ToolExecutionComponent>(),
+		chatContainer,
+		footer: { invalidate: vi.fn() },
+		ui: { requestRender: vi.fn() } as unknown as TUI,
+		settingsManager: {
+			getShowImages: () => false,
+			getImageWidthCells: () => 60,
+			getShowCacheMissNotices: () => false,
+		},
+		sessionManager: { getCwd: () => process.cwd(), getEntries: () => [] },
+		session: { retryAttempt: 0, modelRegistry: { find: () => undefined } },
+		toolOutputExpanded: false,
+		isInitialized: true,
+		updateEditorBorderColor: vi.fn(),
+		getRegisteredToolDefinition: (_toolName: string) => undefined,
+		maybeShowAssistantDiagnostics: vi.fn(),
+		renderSessionItems: (InteractiveMode.prototype as unknown as { renderSessionItems: RenderSessionItems })
+			.renderSessionItems,
+		addMessageToChat(message: AgentMessage) {
+			chatContainer.addChild(new Text(message.role, 0, 0));
+		},
+	};
+}
+
+function createAssistantToolCallMessage(): AssistantMessage {
+	return {
+		role: "assistant",
+		content: [
+			{
+				type: "toolCall",
+				id: TOOL_CALL_ID,
+				name: TOOL_NAME,
+				arguments: { delayMs: 10_000 },
+			},
+		],
+		api: "test-api",
+		provider: "test-provider",
+		model: "test-model",
+		usage: EMPTY_USAGE,
+		stopReason: "toolUse",
+		timestamp: Date.now(),
+	};
+}
+
+function createToolResultMessage(text: string): ToolResultMessage {
+	return {
+		role: "toolResult",
+		toolCallId: TOOL_CALL_ID,
+		toolName: TOOL_NAME,
+		content: [{ type: "text", text }],
+		isError: false,
+		timestamp: Date.now(),
+	};
+}
+
+function createSessionEntries(messages: AgentMessage[]): SessionEntry[] {
+	let parentId: string | null = null;
+	return messages.map((message, index) => {
+		const entry: SessionEntry = {
+			type: "message",
+			id: `entry-${index}`,
+			parentId,
+			timestamp: new Date().toISOString(),
+			message,
+		};
+		parentId = entry.id;
+		return entry;
+	});
+}
+
+function renderChat(container: Container): string {
+	return stripAnsi(container.render(120).join("\n"));
+}
+
+describe("InteractiveMode.renderSessionEntries", () => {
+	beforeAll(() => {
+		initTheme("dark");
+	});
+
+	test("keeps unresolved rendered tool calls registered for live completion events", async () => {
+		const fakeThis = createFakeInteractiveModeThis();
+		const renderSessionEntries = (
+			InteractiveMode.prototype as unknown as { renderSessionEntries: RenderSessionEntries }
+		).renderSessionEntries;
+		const handleEvent = (InteractiveMode.prototype as unknown as { handleEvent: HandleEvent }).handleEvent;
+
+		renderSessionEntries.call(fakeThis, createSessionEntries([createAssistantToolCallMessage()]));
+
+		expect(fakeThis.pendingTools.has(TOOL_CALL_ID)).toBe(true);
+
+		await handleEvent.call(fakeThis, {
+			type: "tool_execution_end",
+			toolCallId: TOOL_CALL_ID,
+			toolName: TOOL_NAME,
+			result: { content: [{ type: "text", text: "FINAL_RESULT" }], details: undefined },
+			isError: false,
+		});
+
+		expect(fakeThis.pendingTools.has(TOOL_CALL_ID)).toBe(false);
+		expect(renderChat(fakeThis.chatContainer)).toContain("FINAL_RESULT");
+	});
+
+	test("does not keep completed historical tool calls registered as pending", () => {
+		const fakeThis = createFakeInteractiveModeThis();
+		const renderSessionEntries = (
+			InteractiveMode.prototype as unknown as { renderSessionEntries: RenderSessionEntries }
+		).renderSessionEntries;
+
+		renderSessionEntries.call(
+			fakeThis,
+			createSessionEntries([createAssistantToolCallMessage(), createToolResultMessage("HISTORICAL_RESULT")]),
+		);
+
+		expect(fakeThis.pendingTools.size).toBe(0);
+		expect(renderChat(fakeThis.chatContainer)).toContain("HISTORICAL_RESULT");
+	});
+});

packages/coding-agent/test/suite/regressions/5080-signal-shutdown-extension-cleanup.test.ts

@@ -0,0 +1,185 @@
+import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import chalk from "chalk";
+import { afterEach, describe, expect, test, vi } from "vitest";
+import { APP_NAME } from "../../../src/config.ts";
+import type { SessionManager } from "../../../src/core/session-manager.ts";
+import { InteractiveMode } from "../../../src/modes/interactive/interactive-mode.ts";
+
+// Regression for https://github.com/earendil-works/pi/issues/5080
+//
+// On SIGTERM/SIGHUP the graceful shutdown must emit `session_shutdown`
+// (runtimeHost.dispose) BEFORE touching the terminal. Extension teardown such
+// as removing a socket does not write to the tty, so it must not be skipped if
+// a later terminal-restore write fails on a dead or stalled terminal. The
+// interactive quit path (Ctrl+D, /quit) keeps the opposite order to preserve
+// the final TUI frame.
+
+type ShutdownThis = {
+	isShuttingDown: boolean;
+	unregisterSignalHandlers: () => void;
+	runtimeHost: { dispose: () => Promise<void> };
+	ui: { terminal: { drainInput: (ms: number) => Promise<void> } };
+	themeController: { disableAutoSync: () => void };
+	stop: () => void;
+	sessionManager: SessionManager;
+};
+
+type InteractiveModePrototypeWithShutdown = {
+	shutdown(this: ShutdownThis, options?: { fromSignal?: boolean }): Promise<void>;
+};
+
+const interactiveModePrototype = InteractiveMode.prototype as unknown;
+const tempDirs: string[] = [];
+const originalStdoutIsTTY = Object.getOwnPropertyDescriptor(process.stdout, "isTTY");
+
+class ProcessExitError extends Error {}
+
+function createSessionManager(options: { sessionFile?: string } = {}): SessionManager {
+	return {
+		isPersisted: () => options.sessionFile !== undefined,
+		getSessionFile: () => options.sessionFile,
+		getSessionId: () => "test-session",
+		getSessionDir: () => "/tmp/pi-sessions",
+		usesDefaultSessionDir: () => true,
+	} as unknown as SessionManager;
+}
+
+function createTempFile(): string {
+	const dir = mkdtempSync(join(tmpdir(), "pi-shutdown-resume-hint-"));
+	tempDirs.push(dir);
+	const file = join(dir, "session.jsonl");
+	writeFileSync(file, "\n");
+	return file;
+}
+
+function setStdoutIsTTY(value: boolean): void {
+	Object.defineProperty(process.stdout, "isTTY", { configurable: true, value });
+}
+
+function restoreStdoutIsTTY(): void {
+	if (originalStdoutIsTTY) {
+		Object.defineProperty(process.stdout, "isTTY", originalStdoutIsTTY);
+	} else {
+		Reflect.deleteProperty(process.stdout, "isTTY");
+	}
+}
+
+function createContext(order: string[], sessionManager = createSessionManager()): ShutdownThis {
+	return {
+		isShuttingDown: false,
+		unregisterSignalHandlers: vi.fn(),
+		runtimeHost: {
+			dispose: vi.fn(async () => {
+				order.push("dispose");
+			}),
+		},
+		ui: {
+			terminal: {
+				drainInput: vi.fn(async () => {
+					order.push("drainInput");
+				}),
+			},
+		},
+		themeController: { disableAutoSync: vi.fn() },
+		stop: vi.fn(() => {
+			order.push("stop");
+		}),
+		sessionManager,
+	};
+}
+
+async function callShutdown(context: ShutdownThis, options?: { fromSignal?: boolean }): Promise<void> {
+	try {
+		await (interactiveModePrototype as InteractiveModePrototypeWithShutdown).shutdown.call(context, options);
+	} catch (error) {
+		if (!(error instanceof ProcessExitError)) throw error;
+	}
+}
+
+describe("InteractiveMode.shutdown ordering (#5080)", () => {
+	afterEach(() => {
+		vi.restoreAllMocks();
+		restoreStdoutIsTTY();
+		for (const dir of tempDirs.splice(0)) {
+			rmSync(dir, { recursive: true, force: true });
+		}
+	});
+
+	test("signal-triggered shutdown emits session_shutdown before terminal writes", async () => {
+		vi.spyOn(process, "exit").mockImplementation((() => {
+			throw new ProcessExitError();
+		}) as typeof process.exit);
+		const order: string[] = [];
+		const context = createContext(order);
+
+		await callShutdown(context, { fromSignal: true });
+
+		expect(order).toEqual(["dispose", "drainInput", "stop"]);
+		expect(context.isShuttingDown).toBe(true);
+	});
+
+	test("interactive quit stops the TUI before emitting session_shutdown", async () => {
+		vi.spyOn(process, "exit").mockImplementation((() => {
+			throw new ProcessExitError();
+		}) as typeof process.exit);
+		const order: string[] = [];
+		const context = createContext(order);
+
+		await callShutdown(context);
+
+		expect(order).toEqual(["drainInput", "stop", "dispose"]);
+	});
+
+	test("interactive quit prints a resume hint for persisted sessions", async () => {
+		vi.spyOn(process, "exit").mockImplementation((() => {
+			throw new ProcessExitError();
+		}) as typeof process.exit);
+		const stdoutWrite = vi
+			.spyOn(process.stdout, "write")
+			.mockImplementation((() => true) as typeof process.stdout.write);
+		setStdoutIsTTY(true);
+		const order: string[] = [];
+		const context = createContext(order, createSessionManager({ sessionFile: createTempFile() }));
+
+		await callShutdown(context);
+
+		expect(order).toEqual(["drainInput", "stop", "dispose"]);
+		expect(stdoutWrite).toHaveBeenCalledWith(
+			`${chalk.dim("To resume this session:")} ${APP_NAME} --session test-session\n`,
+		);
+	});
+
+	test("signal-triggered shutdown does not print a resume hint", async () => {
+		vi.spyOn(process, "exit").mockImplementation((() => {
+			throw new ProcessExitError();
+		}) as typeof process.exit);
+		const stdoutWrite = vi
+			.spyOn(process.stdout, "write")
+			.mockImplementation((() => true) as typeof process.stdout.write);
+		setStdoutIsTTY(true);
+		const order: string[] = [];
+		const context = createContext(order, createSessionManager({ sessionFile: createTempFile() }));
+
+		await callShutdown(context, { fromSignal: true });
+
+		for (const call of stdoutWrite.mock.calls) {
+			expect(call[0]).not.toContain("To resume this session:");
+		}
+	});
+
+	test("re-entrant shutdown is a no-op", async () => {
+		vi.spyOn(process, "exit").mockImplementation((() => {
+			throw new ProcessExitError();
+		}) as typeof process.exit);
+		const order: string[] = [];
+		const context = createContext(order);
+		context.isShuttingDown = true;
+
+		await callShutdown(context, { fromSignal: true });
+
+		expect(order).toEqual([]);
+		expect(context.runtimeHost.dispose).not.toHaveBeenCalled();
+	});
+});

packages/coding-agent/test/suite/regressions/5109-exclude-tools.test.ts

@@ -0,0 +1,81 @@
+import { Type } from "typebox";
+import { describe, expect, it } from "vitest";
+import type { ExtensionFactory } from "../../../src/index.ts";
+import { createHarness } from "../harness.ts";
+
+function toolNames(tools: Array<{ name: string }>): string[] {
+	return tools.map((tool) => tool.name).sort();
+}
+
+describe("regression #5109: exclude tools", () => {
+	const extensionFactories: ExtensionFactory[] = [
+		(pi) => {
+			pi.on("session_start", () => {
+				pi.registerTool({
+					name: "ask_question",
+					label: "Ask Question",
+					description: "Ask a question",
+					promptSnippet: "Ask a question",
+					parameters: Type.Object({}),
+					execute: async () => ({
+						content: [{ type: "text", text: "ok" }],
+						details: {},
+					}),
+				});
+				pi.registerTool({
+					name: "dynamic_tool",
+					label: "Dynamic Tool",
+					description: "Dynamic test tool",
+					promptSnippet: "Run dynamic test behavior",
+					parameters: Type.Object({}),
+					execute: async () => ({
+						content: [{ type: "text", text: "ok" }],
+						details: {},
+					}),
+				});
+			});
+		},
+	];
+
+	it("filters built-in and extension tools from available and active tools", async () => {
+		const harness = await createHarness({
+			excludedToolNames: ["read", "ask_question"],
+			extensionFactories,
+		});
+		try {
+			await harness.session.bindExtensions({});
+
+			const allToolNames = toolNames(harness.session.getAllTools());
+			expect(allToolNames).not.toContain("read");
+			expect(allToolNames).not.toContain("ask_question");
+			expect(allToolNames).toContain("bash");
+			expect(allToolNames).toContain("dynamic_tool");
+			expect(harness.session.getActiveToolNames().sort()).toEqual(["bash", "dynamic_tool", "edit", "write"]);
+			expect(harness.session.systemPrompt).not.toContain("- read:");
+			expect(harness.session.systemPrompt).not.toContain("ask_question");
+			expect(harness.session.systemPrompt).toContain("- dynamic_tool: Run dynamic test behavior");
+		} finally {
+			harness.cleanup();
+		}
+	});
+
+	it("lets excluded tools override the allowlist", async () => {
+		const harness = await createHarness({
+			allowedToolNames: ["read", "bash", "ask_question"],
+			excludedToolNames: ["read", "ask_question"],
+			initialActiveToolNames: ["read", "bash", "ask_question"],
+			extensionFactories,
+		});
+		try {
+			await harness.session.bindExtensions({});
+
+			expect(toolNames(harness.session.getAllTools())).toEqual(["bash"]);
+			expect(harness.session.getActiveToolNames()).toEqual(["bash"]);
+			expect(harness.session.systemPrompt).toContain("- bash:");
+			expect(harness.session.systemPrompt).not.toContain("- read:");
+			expect(harness.session.systemPrompt).not.toContain("ask_question");
+		} finally {
+			harness.cleanup();
+		}
+	});
+});

packages/coding-agent/test/suite/regressions/5208-late-bash-output.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it } from "vitest";
+import { type BashOperations, createBashTool } from "../../../src/core/tools/bash.ts";
+
+function getTextOutput(result: { content?: Array<{ type: string; text?: string }> }): string {
+	return (
+		result.content
+			?.filter((block) => block.type === "text")
+			.map((block) => block.text ?? "")
+			.join("\n") ?? ""
+	);
+}
+
+describe("regression #5208: late bash output callbacks", () => {
+	it("ignores output callbacks after bash operations resolve", async () => {
+		const operations: BashOperations = {
+			exec: async (_command, _cwd, { onData }) => {
+				onData(Buffer.from("before\n", "utf-8"));
+				setTimeout(() => onData(Buffer.from("late\n", "utf-8")), 0);
+				return { exitCode: 0 };
+			},
+		};
+		const bash = createBashTool(process.cwd(), { operations });
+
+		const result = await bash.execute("test-call-late-output", { command: "late-output" });
+		await new Promise((resolve) => setTimeout(resolve, 20));
+
+		expect(getTextOutput(result).trim()).toBe("before");
+	});
+});

packages/coding-agent/test/suite/regressions/5217-compaction-reason.test.ts

@@ -0,0 +1,95 @@
+import { fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import type { ExtensionFactory } from "../../../src/index.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+type SessionWithCompactionInternals = {
+	_runAutoCompaction: (reason: "overflow" | "threshold", willRetry: boolean) => Promise<boolean>;
+};
+
+interface RecordedCompactionEvent {
+	type: "session_before_compact" | "session_compact";
+	reason: "manual" | "threshold" | "overflow";
+	willRetry: boolean;
+}
+
+function recordingExtension(recorded: RecordedCompactionEvent[]): ExtensionFactory {
+	return (pi) => {
+		pi.on("session_before_compact", async (event) => {
+			recorded.push({ type: event.type, reason: event.reason, willRetry: event.willRetry });
+			return {
+				compaction: {
+					summary: "summary from extension",
+					firstKeptEntryId: event.preparation.firstKeptEntryId,
+					tokensBefore: event.preparation.tokensBefore,
+					details: {},
+				},
+			};
+		});
+		pi.on("session_compact", async (event) => {
+			recorded.push({ type: event.type, reason: event.reason, willRetry: event.willRetry });
+		});
+	};
+}
+
+async function createCompactionHarness(recorded: RecordedCompactionEvent[]): Promise<Harness> {
+	const harness = await createHarness({
+		settings: { compaction: { keepRecentTokens: 1 } },
+		extensionFactories: [recordingExtension(recorded)],
+	});
+	harness.setResponses([fauxAssistantMessage("one"), fauxAssistantMessage("two")]);
+	await harness.session.prompt("first");
+	await harness.session.prompt("second");
+	return harness;
+}
+
+describe("issue #5217 compaction reason on extension events", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("reports manual reason for compact()", async () => {
+		const recorded: RecordedCompactionEvent[] = [];
+		const harness = await createCompactionHarness(recorded);
+		harnesses.push(harness);
+
+		await harness.session.compact();
+
+		expect(recorded).toEqual([
+			{ type: "session_before_compact", reason: "manual", willRetry: false },
+			{ type: "session_compact", reason: "manual", willRetry: false },
+		]);
+	});
+
+	it("reports threshold reason for auto-compaction", async () => {
+		const recorded: RecordedCompactionEvent[] = [];
+		const harness = await createCompactionHarness(recorded);
+		harnesses.push(harness);
+		const sessionInternals = harness.session as unknown as SessionWithCompactionInternals;
+
+		await sessionInternals._runAutoCompaction("threshold", false);
+
+		expect(recorded).toEqual([
+			{ type: "session_before_compact", reason: "threshold", willRetry: false },
+			{ type: "session_compact", reason: "threshold", willRetry: false },
+		]);
+	});
+
+	it("reports overflow reason and willRetry for overflow recovery", async () => {
+		const recorded: RecordedCompactionEvent[] = [];
+		const harness = await createCompactionHarness(recorded);
+		harnesses.push(harness);
+		const sessionInternals = harness.session as unknown as SessionWithCompactionInternals;
+
+		await sessionInternals._runAutoCompaction("overflow", true);
+
+		expect(recorded).toEqual([
+			{ type: "session_before_compact", reason: "overflow", willRetry: true },
+			{ type: "session_compact", reason: "overflow", willRetry: true },
+		]);
+	});
+});

packages/coding-agent/test/suite/regressions/5303-bash-output-truncation.test.ts

@@ -0,0 +1,82 @@
+import type { ChildProcessByStdio } from "node:child_process";
+import { EventEmitter } from "node:events";
+import { PassThrough } from "node:stream";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { waitForChildProcess } from "../../../src/utils/child-process.ts";
+
+/**
+ * Regression test for https://github.com/earendil-works/pi/issues/5303
+ *
+ * waitForChildProcess armed a fixed 100ms timer on `exit` and destroyed the
+ * stdio streams when it fired. When a short-lived detached descendant kept the
+ * stdout pipe open, `close` never fired, so that timer was the only thing that
+ * resolved the wait, and any output written more than 100ms after exit was
+ * binned. In practice every git commit whose pre-commit hook runs lint-staged
+ * came back truncated mid-listr2 output, read by the model as a hang.
+ *
+ * The fix re-arms the grace on each chunk, so an actively writing pipe keeps us
+ * reading while a genuinely idle held-open handle still releases after the
+ * grace elapses. Both behaviours are covered below with virtual time so host
+ * load cannot reorder a real subprocess's writes and the grace timer.
+ */
+describe("issue #5303 bash output truncation past exit", () => {
+	function createChild(): ChildProcessByStdio<null, PassThrough, PassThrough> {
+		return Object.assign(new EventEmitter(), {
+			stdin: null,
+			stdout: new PassThrough(),
+			stderr: new PassThrough(),
+		}) as unknown as ChildProcessByStdio<null, PassThrough, PassThrough>;
+	}
+
+	beforeEach(() => {
+		vi.useFakeTimers();
+	});
+
+	afterEach(() => {
+		vi.useRealTimers();
+	});
+
+	it("captures output emitted after exit while a descendant holds stdout open", async () => {
+		const child = createChild();
+		let output = "";
+		child.stdout.on("data", (chunk: Buffer) => {
+			output += chunk.toString();
+		});
+		let resolved = false;
+		const waiting = waitForChildProcess(child).then((exitCode) => {
+			resolved = true;
+			return exitCode;
+		});
+
+		child.stdout.write("HEAD\n");
+		child.emit("exit", 0, null);
+		for (let index = 1; index <= 6; index++) {
+			await vi.advanceTimersByTimeAsync(50);
+			child.stdout.write(`TICK${index}\n`);
+		}
+		await vi.advanceTimersByTimeAsync(99);
+		expect(resolved).toBe(false);
+		await vi.advanceTimersByTimeAsync(1);
+
+		expect(await waiting).toBe(0);
+		expect(output).toContain("HEAD");
+		expect(output).toContain("TICK6");
+	});
+
+	it("resolves after the grace when a descendant holds stdout open but stays quiet", async () => {
+		const child = createChild();
+		let resolved = false;
+		const waiting = waitForChildProcess(child).then((exitCode) => {
+			resolved = true;
+			return exitCode;
+		});
+
+		child.stdout.write("DONE\n");
+		child.emit("exit", 0, null);
+		await vi.advanceTimersByTimeAsync(99);
+		expect(resolved).toBe(false);
+		await vi.advanceTimersByTimeAsync(1);
+
+		expect(await waiting).toBe(0);
+	});
+});

packages/coding-agent/test/suite/regressions/5433-extension-oauth-prompt-input.test.ts

@@ -0,0 +1,119 @@
+import { setKeybindings, type TUI } from "@earendil-works/pi-tui";
+import { beforeAll, beforeEach, describe, expect, test, vi } from "vitest";
+import { KeybindingsManager } from "../../../src/core/keybindings.ts";
+import { LoginDialogComponent } from "../../../src/modes/interactive/components/login-dialog.ts";
+import { initTheme } from "../../../src/modes/interactive/theme/theme.ts";
+import { stripAnsi } from "../../../src/utils/ansi.ts";
+
+vi.mock("../../../src/utils/open-browser.ts", () => ({
+	openBrowser: vi.fn(),
+}));
+
+function createDialog(): LoginDialogComponent {
+	return new LoginDialogComponent(
+		{ requestRender: vi.fn() } as unknown as TUI,
+		"prompt-repro",
+		() => {},
+		"Prompt Repro",
+	);
+}
+
+function renderDialog(dialog: LoginDialogComponent): string[] {
+	return stripAnsi(dialog.render(120).join("\n"))
+		.split("\n")
+		.map((line) => line.trimEnd());
+}
+
+function countRenderedValue(lines: string[], value: string): number {
+	return lines.filter((line) => line.trim() === `> ${value}`).length;
+}
+
+describe("LoginDialogComponent OAuth prompts", () => {
+	beforeAll(() => {
+		initTheme("dark");
+	});
+
+	beforeEach(() => {
+		setKeybindings(new KeybindingsManager());
+	});
+
+	test("keeps previous prompt input stable when a later prompt is active", async () => {
+		const dialog = createDialog();
+
+		const firstPrompt = dialog.showPrompt("First prompt:", "first-value");
+		dialog.handleInput("first-value");
+		dialog.handleInput("\n");
+		await expect(firstPrompt).resolves.toBe("first-value");
+
+		const secondPrompt = dialog.showPrompt("Second prompt:");
+		dialog.handleInput("second-secret-demo");
+
+		const lines = renderDialog(dialog);
+		expect(lines.join("\n")).toContain("First prompt:");
+		expect(lines.join("\n")).toContain("Second prompt:");
+		expect(countRenderedValue(lines, "first-value")).toBe(1);
+		expect(countRenderedValue(lines, "second-secret-demo")).toBe(1);
+
+		dialog.handleInput("\n");
+		await expect(secondPrompt).resolves.toBe("second-secret-demo");
+	});
+
+	test("preserves auth instructions when showing a prompt", () => {
+		const dialog = createDialog();
+
+		dialog.showAuth("https://example.invalid/login", "Authorize the extension");
+		dialog.showPrompt("First prompt:");
+
+		const output = renderDialog(dialog).join("\n");
+		expect(output).toContain("https://example.invalid/login");
+		expect(output).toContain("Authorize the extension");
+		expect(output).toContain("First prompt:");
+	});
+
+	test("preserves neutral information and links when showing a prompt", () => {
+		const dialog = createDialog();
+
+		dialog.showInfo("Configure credentials outside pi.", [
+			{ label: "Provider documentation", url: "https://example.invalid/docs" },
+		]);
+		dialog.showPrompt("Press Enter to continue:");
+
+		const output = renderDialog(dialog).join("\n");
+		expect(output).toContain("Configure credentials outside pi.");
+		expect(output).toContain("Provider documentation: https://example.invalid/docs");
+		expect(output).toContain("Press Enter to continue:");
+	});
+
+	test("preserves setup details when showing a prompt", () => {
+		const dialog = createDialog();
+
+		dialog.showDetails(["AWS credential setup:", "providers.md"]);
+		dialog.showPrompt("Enter API key:");
+
+		const output = renderDialog(dialog).join("\n");
+		expect(output).toContain("AWS credential setup:");
+		expect(output).toContain("providers.md");
+		expect(output).toContain("Enter API key:");
+	});
+
+	test("keeps previous manual input stable when a later prompt is active", async () => {
+		const dialog = createDialog();
+
+		const manualInput = dialog.showManualInput("Paste callback URL:");
+		dialog.handleInput("callback-value");
+		dialog.handleInput("\n");
+		await expect(manualInput).resolves.toBe("callback-value");
+
+		const prompt = dialog.showPrompt("Second prompt:");
+		dialog.handleInput("second-secret-demo");
+
+		const lines = renderDialog(dialog);
+		expect(lines.join("\n")).toContain("Paste callback URL:");
+		expect(lines.join("\n")).toContain("Second prompt:");
+		expect(countRenderedValue(lines, "callback-value")).toBe(1);
+		expect(countRenderedValue(lines, "second-secret-demo")).toBe(1);
+
+		dialog.handleInput("\n");
+		await expect(prompt).resolves.toBe("second-secret-demo");
+	});
+});

packages/coding-agent/test/suite/regressions/5596-missing-theme-export.test.ts

@@ -0,0 +1,90 @@
+import { existsSync, mkdtempSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { Agent } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, registerFauxProvider, streamSimple } from "@earendil-works/pi-ai/compat";
+import { afterEach, describe, expect, it } from "vitest";
+import { AgentSession } from "../../../src/core/agent-session.ts";
+import { AuthStorage } from "../../../src/core/auth-storage.ts";
+import { convertToLlm } from "../../../src/core/messages.ts";
+import { SessionManager } from "../../../src/core/session-manager.ts";
+import { SettingsManager } from "../../../src/core/settings-manager.ts";
+import { initTheme } from "../../../src/modes/interactive/theme/theme.ts";
+import { createInMemoryModelRegistry, getModelRuntime } from "../../model-runtime-test-utils.ts";
+import { createTestResourceLoader } from "../../utilities.ts";
+
+describe("regression #5596: missing configured theme export", () => {
+	const cleanups: Array<() => void> = [];
+
+	afterEach(() => {
+		while (cleanups.length > 0) {
+			cleanups.pop()?.();
+		}
+		initTheme("dark");
+	});
+
+	it("exports with the active fallback theme when the configured theme is missing", async () => {
+		const tempDir = mkdtempSync(join(tmpdir(), "pi-5596-"));
+		const faux = registerFauxProvider({
+			models: [{ id: "faux-1", reasoning: false }],
+		});
+		faux.setResponses([fauxAssistantMessage("hello")]);
+
+		const model = faux.getModel();
+		const authStorage = AuthStorage.inMemory();
+		await authStorage.modify(model.provider, async () => ({ type: "api_key", key: "faux-key" }));
+		const modelRegistry = await createInMemoryModelRegistry(authStorage);
+		modelRegistry.registerProvider(model.provider, {
+			baseUrl: model.baseUrl,
+			apiKey: "faux-key",
+			api: faux.api,
+			models: faux.models.map((registeredModel) => ({
+				id: registeredModel.id,
+				name: registeredModel.name,
+				api: registeredModel.api,
+				reasoning: registeredModel.reasoning,
+				input: registeredModel.input,
+				cost: registeredModel.cost,
+				contextWindow: registeredModel.contextWindow,
+				maxTokens: registeredModel.maxTokens,
+				baseUrl: registeredModel.baseUrl,
+			})),
+		});
+
+		const settingsManager = SettingsManager.inMemory({ theme: "missing-theme" });
+		const sessionManager = SessionManager.create(tempDir, join(tempDir, "sessions"));
+		const agent = new Agent({
+			getApiKey: () => "faux-key",
+			initialState: {
+				model,
+				systemPrompt: "You are a test assistant.",
+				tools: [],
+			},
+			convertToLlm,
+			streamFn: streamSimple,
+		});
+		const session = new AgentSession({
+			agent,
+			sessionManager,
+			settingsManager,
+			cwd: tempDir,
+			modelRuntime: getModelRuntime(modelRegistry),
+			resourceLoader: createTestResourceLoader(),
+		});
+		cleanups.push(() => {
+			session.dispose();
+			faux.unregister();
+			if (existsSync(tempDir)) {
+				rmSync(tempDir, { recursive: true, force: true });
+			}
+		});
+
+		await session.prompt("hi");
+		initTheme(settingsManager.getTheme());
+
+		const outputPath = join(tempDir, "export.html");
+		await expect(session.exportToHtml(outputPath)).resolves.toBe(outputPath);
+		expect(existsSync(outputPath)).toBe(true);
+		expect(settingsManager.getTheme()).toBe("missing-theme");
+	});
+});

packages/coding-agent/test/suite/regressions/5661-uppercase-header-values.test.ts

@@ -0,0 +1,91 @@
+import { readFileSync, writeFileSync } from "node:fs";
+import { join } from "node:path";
+import { afterEach, describe, expect, it } from "vitest";
+import { ENV_AGENT_DIR } from "../../../src/config.ts";
+import { AuthStorage } from "../../../src/core/auth-storage.ts";
+import { runMigrations } from "../../../src/migrations.ts";
+import { createModelRegistry } from "../../model-runtime-test-utils.ts";
+import { createHarness } from "../harness.ts";
+
+describe("regression #5661: uppercase models.json header values", () => {
+	const cleanups: Array<() => void> = [];
+
+	afterEach(() => {
+		while (cleanups.length > 0) {
+			cleanups.pop()?.();
+		}
+	});
+
+	function withAgentDir(agentDir: string, fn: () => void): void {
+		const previousAgentDir = process.env[ENV_AGENT_DIR];
+		process.env[ENV_AGENT_DIR] = agentDir;
+		try {
+			fn();
+		} finally {
+			if (previousAgentDir === undefined) {
+				delete process.env[ENV_AGENT_DIR];
+			} else {
+				process.env[ENV_AGENT_DIR] = previousAgentDir;
+			}
+		}
+	}
+
+	it("keeps uppercase header strings as literals during startup migrations", async () => {
+		const harness = await createHarness({ withConfiguredAuth: false });
+		cleanups.push(harness.cleanup);
+
+		const envKeys = ["CUSTOM_API_KEY", "BEARER"];
+		const savedEnv: Record<string, string | undefined> = {};
+		for (const key of envKeys) {
+			savedEnv[key] = process.env[key];
+			process.env[key] = `env-${key}`;
+		}
+		cleanups.push(() => {
+			for (const key of envKeys) {
+				if (savedEnv[key] === undefined) {
+					delete process.env[key];
+				} else {
+					process.env[key] = savedEnv[key];
+				}
+			}
+		});
+
+		const modelsPath = join(harness.tempDir, "models.json");
+		writeFileSync(
+			modelsPath,
+			`${JSON.stringify(
+				{
+					providers: {
+						"my-provider": {
+							baseUrl: "https://example.com/v1",
+							apiKey: "CUSTOM_API_KEY",
+							api: "openai-completions",
+							headers: { Authorization: "BEARER" },
+							models: [{ id: "my-model" }],
+						},
+					},
+				},
+				null,
+				2,
+			)}\n`,
+			"utf-8",
+		);
+
+		withAgentDir(harness.tempDir, () => runMigrations(harness.tempDir));
+
+		const migrated = JSON.parse(readFileSync(modelsPath, "utf-8")) as {
+			providers: Record<string, { apiKey?: string; headers?: Record<string, string> }>;
+		};
+		expect(migrated.providers["my-provider"]?.apiKey).toBe("CUSTOM_API_KEY");
+		expect(migrated.providers["my-provider"]?.headers?.Authorization).toBe("BEARER");
+
+		const registry = await createModelRegistry(AuthStorage.create(join(harness.tempDir, "auth.json")), modelsPath);
+		const model = registry.find("my-provider", "my-model");
+		expect(model).toBeDefined();
+		expect(await registry.getApiKeyAndHeaders(model!)).toMatchObject({
+			ok: true,
+			apiKey: "CUSTOM_API_KEY",
+			headers: { Authorization: "BEARER" },
+		});
+	});
+});

packages/coding-agent/test/suite/regressions/5724-sigterm-signal-exit.test.ts

@@ -0,0 +1,94 @@
+import { afterEach, describe, expect, test, vi } from "vitest";
+import { InteractiveMode } from "../../../src/modes/interactive/interactive-mode.ts";
+
+// Regression for https://github.com/earendil-works/pi/issues/5724
+//
+// `proper-lockfile` installs `signal-exit`, whose signal listener re-sends
+// SIGTERM/SIGHUP when it observes no other process listeners during the same
+// signal dispatch. InteractiveMode must therefore keep its signal handlers
+// registered until async terminal cleanup has completed.
+
+type ShutdownThis = {
+	isShuttingDown: boolean;
+	unregisterSignalHandlers: () => void;
+	runtimeHost: { dispose: () => Promise<void> };
+	ui: { terminal: { drainInput: (ms: number) => Promise<void> } };
+	themeController: { disableAutoSync: () => void };
+	stop: () => void;
+};
+
+type InteractiveModePrototypeWithShutdown = {
+	shutdown(this: ShutdownThis, options?: { fromSignal?: boolean }): Promise<void>;
+};
+
+const interactiveModePrototype = InteractiveMode.prototype as unknown;
+
+class ProcessExitError extends Error {}
+
+function deferred(): { promise: Promise<void>; resolve: () => void } {
+	let resolve: (() => void) | undefined;
+	const promise = new Promise<void>((res) => {
+		resolve = res;
+	});
+	return {
+		promise,
+		resolve: () => resolve?.(),
+	};
+}
+
+async function callShutdown(context: ShutdownThis, options?: { fromSignal?: boolean }): Promise<void> {
+	try {
+		await (interactiveModePrototype as InteractiveModePrototypeWithShutdown).shutdown.call(context, options);
+	} catch (error) {
+		if (!(error instanceof ProcessExitError)) throw error;
+	}
+}
+
+describe("InteractiveMode SIGTERM shutdown with signal-exit (#5724)", () => {
+	afterEach(() => {
+		vi.restoreAllMocks();
+	});
+
+	test("keeps signal handlers registered while signal-triggered cleanup is pending", async () => {
+		vi.spyOn(process, "exit").mockImplementation((() => {
+			throw new ProcessExitError();
+		}) as typeof process.exit);
+
+		const order: string[] = [];
+		const dispose = deferred();
+		const context: ShutdownThis = {
+			isShuttingDown: false,
+			unregisterSignalHandlers: vi.fn(() => {
+				order.push("unregister");
+			}),
+			runtimeHost: {
+				dispose: vi.fn(() => {
+					order.push("dispose");
+					return dispose.promise;
+				}),
+			},
+			ui: {
+				terminal: {
+					drainInput: vi.fn(async () => {
+						order.push("drainInput");
+					}),
+				},
+			},
+			themeController: { disableAutoSync: vi.fn() },
+			stop: vi.fn(() => {
+				order.push("stop");
+			}),
+		};
+
+		const shutdownPromise = callShutdown(context, { fromSignal: true });
+		await Promise.resolve();
+
+		expect(order).toEqual(["dispose"]);
+		expect(context.unregisterSignalHandlers).not.toHaveBeenCalled();
+
+		dispose.resolve();
+		await shutdownPromise;
+
+		expect(order).toEqual(["dispose", "drainInput", "stop"]);
+	});
+});

packages/coding-agent/test/suite/regressions/5868-rpc-unknown-command-id.test.ts

@@ -0,0 +1,113 @@
+import { afterEach, describe, expect, test, vi } from "vitest";
+import type { AgentSessionRuntime } from "../../../src/core/agent-session-runtime.ts";
+import { runRpcMode } from "../../../src/modes/rpc/rpc-mode.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+// Regression for https://github.com/earendil-works/pi/issues/5868
+
+const rpcIo = vi.hoisted(() => ({
+	outputLines: [] as string[],
+	lineHandler: undefined as ((line: string) => void) | undefined,
+}));
+
+vi.mock("../../../src/core/output-guard.js", () => ({
+	flushRawStdout: vi.fn(async () => {}),
+	takeOverStdout: vi.fn(),
+	waitForRawStdoutBackpressure: vi.fn(async () => {}),
+	writeRawStdout: (line: string) => {
+		rpcIo.outputLines.push(line);
+	},
+}));
+
+vi.mock("../../../src/modes/interactive/theme/theme.js", () => ({ theme: {} }));
+
+vi.mock("../../../src/modes/rpc/jsonl.js", () => ({
+	attachJsonlLineReader: vi.fn((_stream: NodeJS.ReadableStream, onLine: (line: string) => void) => {
+		rpcIo.lineHandler = onLine;
+		return () => {
+			rpcIo.lineHandler = undefined;
+		};
+	}),
+	serializeJsonLine: (value: unknown) => `${JSON.stringify(value)}\n`,
+}));
+
+type NodeListener = Parameters<typeof process.on>[1];
+
+type ListenerSnapshot = {
+	stdinEnd: NodeListener[];
+	signals: Map<NodeJS.Signals, NodeListener[]>;
+};
+
+function takeListenerSnapshot(): ListenerSnapshot {
+	const signals: NodeJS.Signals[] = process.platform === "win32" ? ["SIGTERM"] : ["SIGTERM", "SIGHUP"];
+	return {
+		stdinEnd: process.stdin.listeners("end") as NodeListener[],
+		signals: new Map(signals.map((signal) => [signal, process.listeners(signal) as NodeListener[]])),
+	};
+}
+
+function restoreListeners(snapshot: ListenerSnapshot): void {
+	for (const listener of process.stdin.listeners("end") as NodeListener[]) {
+		if (!snapshot.stdinEnd.includes(listener)) {
+			process.stdin.off("end", listener);
+		}
+	}
+
+	for (const [signal, previousListeners] of snapshot.signals) {
+		for (const listener of process.listeners(signal) as NodeListener[]) {
+			if (!previousListeners.includes(listener)) {
+				process.off(signal, listener);
+			}
+		}
+	}
+}
+
+function parseOutputLines(): Array<Record<string, unknown>> {
+	return rpcIo.outputLines
+		.flatMap((line) => line.split("\n"))
+		.filter((line) => line.trim().length > 0)
+		.map((line) => JSON.parse(line) as Record<string, unknown>);
+}
+
+function createRuntimeHost(harness: Harness): AgentSessionRuntime {
+	return {
+		session: harness.session,
+		newSession: vi.fn(async () => ({ cancelled: true })),
+		switchSession: vi.fn(async () => ({ cancelled: true })),
+		fork: vi.fn(async () => ({ cancelled: true, selectedText: "" })),
+		dispose: vi.fn(async () => {}),
+		setRebindSession: vi.fn(),
+	} as unknown as AgentSessionRuntime;
+}
+
+describe("RPC unknown command responses (#5868)", () => {
+	afterEach(() => {
+		rpcIo.outputLines = [];
+		rpcIo.lineHandler = undefined;
+	});
+
+	test("preserves the request id on unknown command errors", async () => {
+		const listenerSnapshot = takeListenerSnapshot();
+		const harness = await createHarness();
+
+		try {
+			void runRpcMode(createRuntimeHost(harness));
+			await vi.waitFor(() => expect(rpcIo.lineHandler).toBeDefined());
+
+			rpcIo.lineHandler?.(JSON.stringify({ id: "test", type: "foobar" }));
+
+			await vi.waitFor(() => {
+				expect(parseOutputLines()).toContainEqual({
+					id: "test",
+					type: "response",
+					command: "foobar",
+					success: false,
+					error: "Unknown command: foobar",
+				});
+			});
+		} finally {
+			harness.cleanup();
+			restoreListeners(listenerSnapshot);
+		}
+	});
+});

packages/coding-agent/test/suite/regressions/5943-session-start-notify.test.ts

@@ -0,0 +1,519 @@
+import { fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { Container, Text } from "@earendil-works/pi-tui";
+import { describe, expect, it, vi } from "vitest";
+import type { AgentSessionEvent } from "../../../src/core/agent-session.ts";
+import type { ExtensionUIContext } from "../../../src/core/extensions/index.ts";
+import { InteractiveMode } from "../../../src/modes/interactive/interactive-mode.ts";
+import { initTheme, type Theme, theme } from "../../../src/modes/interactive/theme/theme.ts";
+import { createHarness } from "../harness.ts";
+
+function createUiContext(
+	onNotify: (message: string, type: "info" | "warning" | "error" | undefined) => void,
+): ExtensionUIContext {
+	return {
+		select: async () => undefined,
+		confirm: async () => false,
+		input: async () => undefined,
+		notify: onNotify,
+		onTerminalInput: () => () => {},
+		setStatus: () => {},
+		setWorkingMessage: () => {},
+		setWorkingVisible: () => {},
+		setWorkingIndicator: () => {},
+		setHiddenThinkingLabel: () => {},
+		setWidget: () => {},
+		setFooter: () => {},
+		setHeader: () => {},
+		setTitle: () => {},
+		custom: async <T>() => undefined as T,
+		pasteToEditor: () => {},
+		setEditorText: () => {},
+		getEditorText: () => "",
+		editor: async () => undefined,
+		addAutocompleteProvider: () => {},
+		setEditorComponent: () => {},
+		getEditorComponent: () => undefined,
+		get theme() {
+			return theme;
+		},
+		getAllThemes: () => [],
+		getTheme: () => undefined,
+		setTheme: (_theme: string | Theme) => ({ success: false, error: "Theme switching not available in tests" }),
+		getToolsExpanded: () => false,
+		setToolsExpanded: () => {},
+	};
+}
+
+type LoadedResourcesResult<T> = { [K in keyof T]: T[K] } & { diagnostics: [] };
+
+type LoadedResourcesContext = {
+	loadedResourcesContainer: Container;
+	chatContainer: Container;
+	options: { verbose?: boolean };
+	settingsManager: { getQuietStartup: () => boolean };
+	sessionManager: { getCwd: () => string };
+	session: {
+		promptTemplates: [];
+		resourceLoader: {
+			getAgentsFiles: () => LoadedResourcesResult<{ agentsFiles: Array<{ path: string }> }>;
+			getSystemPromptSource: () => { path: string } | undefined;
+			getAppendSystemPromptSources: () => Array<{ path: string }>;
+			getSkills: () => LoadedResourcesResult<{ skills: [] }>;
+			getPrompts: () => LoadedResourcesResult<{ prompts: [] }>;
+			getThemes: () => LoadedResourcesResult<{ themes: [] }>;
+			getExtensions: () => { extensions: []; errors: [] };
+		};
+		extensionRunner: {
+			getCommandDiagnostics: () => [];
+			getShortcutDiagnostics: () => [];
+			getRegisteredCommands: () => [];
+		};
+	};
+	getStartupExpansionState: () => boolean;
+	formatDisplayPath: (resourcePath: string) => string;
+	formatContextPath: (resourcePath: string) => string;
+	getBuiltInCommandConflictDiagnostics: (extensionRunner: LoadedResourcesContext["session"]["extensionRunner"]) => [];
+};
+
+type RebindContext = {
+	unsubscribe?: () => void;
+	applyRuntimeSettings: () => void;
+	renderCurrentSessionState: () => void;
+	bindCurrentSessionExtensions: () => Promise<void>;
+	subscribeToAgent: () => void;
+	updateAvailableProviderCount: () => Promise<void>;
+	updateEditorBorderColor: () => void;
+	updateTerminalTitle: () => void;
+};
+
+type ReloadCommandContext = {
+	hideThinkingBlock: boolean;
+	session: {
+		isStreaming: boolean;
+		isCompacting: boolean;
+		reload: (options?: { beforeSessionStart?: () => void | Promise<void> }) => Promise<void>;
+		resourceLoader: { getThemes: () => { themes: [] } };
+		extensionRunner: unknown;
+		modelRegistry: { getError: () => string | undefined };
+	};
+	settingsManager: {
+		getHttpIdleTimeoutMs: () => number;
+		getHideThinkingBlock: () => boolean;
+		getOutputPad: () => 0 | 1;
+		getEditorPaddingX: () => number;
+		getAutocompleteMaxVisible: () => number;
+		getShowHardwareCursor: () => boolean;
+		getClearOnShrink: () => boolean;
+	};
+	keybindings: { reload: () => void };
+	customHeader?: unknown;
+	builtInHeader?: unknown;
+	editorContainer: { clear: () => void; addChild: (component: unknown) => void };
+	ui: {
+		setFocus: (component: unknown) => void;
+		requestRender: (force?: boolean) => void;
+		setShowHardwareCursor: (enabled: boolean) => void;
+		setClearOnShrink: (enabled: boolean) => void;
+	};
+	editor: unknown;
+	defaultEditor: { setPaddingX: (padding: number) => void; setAutocompleteMaxVisible: (maxVisible: number) => void };
+	themeController: { applyFromSettings: () => Promise<void> };
+	resetExtensionUI: () => void;
+	rebuildChatFromMessages: () => void;
+	setupAutocompleteProvider: () => void;
+	setupExtensionShortcuts: (runner: unknown) => void;
+	showLoadedResources: (options: unknown) => void;
+	maybeSaveImplicitProjectTrustAfterReload: () => boolean;
+	showStatus: (message: string) => void;
+	showWarning: (message: string) => void;
+	showError: (message: string) => void;
+};
+
+type InteractiveModePrototype = {
+	showLoadedResources(
+		this: LoadedResourcesContext,
+		options?: { extensions?: Array<{ path: string }>; force?: boolean; showDiagnosticsWhenQuiet?: boolean },
+	): void;
+	rebindCurrentSession(this: RebindContext, options?: { renderBeforeBind?: boolean }): Promise<void>;
+	handleReloadCommand(this: ReloadCommandContext): Promise<void>;
+};
+
+const interactiveModePrototype = InteractiveMode.prototype as unknown as InteractiveModePrototype;
+
+type ReloadCommandContextOverrides = Omit<
+	Partial<ReloadCommandContext>,
+	"session" | "settingsManager" | "keybindings" | "editorContainer" | "ui" | "defaultEditor" | "themeController"
+> & {
+	session?: Partial<ReloadCommandContext["session"]>;
+	settingsManager?: Partial<ReloadCommandContext["settingsManager"]>;
+	keybindings?: Partial<ReloadCommandContext["keybindings"]>;
+	editorContainer?: Partial<ReloadCommandContext["editorContainer"]>;
+	ui?: Partial<ReloadCommandContext["ui"]>;
+	defaultEditor?: Partial<ReloadCommandContext["defaultEditor"]>;
+	themeController?: Partial<ReloadCommandContext["themeController"]>;
+};
+
+function createReloadCommandContext(overrides: ReloadCommandContextOverrides = {}): ReloadCommandContext {
+	const editor = overrides.editor ?? {};
+	return {
+		hideThinkingBlock: overrides.hideThinkingBlock ?? false,
+		session: {
+			isStreaming: false,
+			isCompacting: false,
+			reload: async (options) => {
+				await options?.beforeSessionStart?.();
+			},
+			resourceLoader: { getThemes: () => ({ themes: [] }) },
+			extensionRunner: {},
+			modelRegistry: { getError: () => undefined },
+			...overrides.session,
+		},
+		settingsManager: {
+			getHttpIdleTimeoutMs: () => 0,
+			getHideThinkingBlock: () => false,
+			getOutputPad: () => 1,
+			getEditorPaddingX: () => 1,
+			getAutocompleteMaxVisible: () => 10,
+			getShowHardwareCursor: () => false,
+			getClearOnShrink: () => false,
+			...overrides.settingsManager,
+		},
+		keybindings: { reload: () => {}, ...overrides.keybindings },
+		editorContainer: { clear: () => {}, addChild: () => {}, ...overrides.editorContainer },
+		ui: {
+			setFocus: () => {},
+			requestRender: () => {},
+			setShowHardwareCursor: () => {},
+			setClearOnShrink: () => {},
+			...overrides.ui,
+		},
+		editor,
+		defaultEditor: { setPaddingX: () => {}, setAutocompleteMaxVisible: () => {}, ...overrides.defaultEditor },
+		themeController: { applyFromSettings: async () => {}, ...overrides.themeController },
+		customHeader: overrides.customHeader,
+		builtInHeader: overrides.builtInHeader,
+		resetExtensionUI: overrides.resetExtensionUI ?? (() => {}),
+		rebuildChatFromMessages: overrides.rebuildChatFromMessages ?? (() => {}),
+		setupAutocompleteProvider: overrides.setupAutocompleteProvider ?? (() => {}),
+		setupExtensionShortcuts: overrides.setupExtensionShortcuts ?? (() => {}),
+		showLoadedResources: overrides.showLoadedResources ?? (() => {}),
+		maybeSaveImplicitProjectTrustAfterReload: overrides.maybeSaveImplicitProjectTrustAfterReload ?? (() => false),
+		showStatus: overrides.showStatus ?? (() => {}),
+		showWarning: overrides.showWarning ?? (() => {}),
+		showError: overrides.showError ?? (() => {}),
+	};
+}
+
+type MessageEvent = Extract<AgentSessionEvent, { type: "message_start" | "message_end" }>;
+
+function getMessageText(event: MessageEvent): string {
+	const message = event.message;
+	if (!("content" in message)) {
+		return "";
+	}
+	const content = message.content;
+	if (typeof content === "string") {
+		return content;
+	}
+	return content
+		.filter((part): part is { type: "text"; text: string } => part.type === "text")
+		.map((part) => part.text)
+		.join("");
+}
+
+function createLoadedResourcesContext(): LoadedResourcesContext {
+	return {
+		loadedResourcesContainer: new Container(),
+		chatContainer: new Container(),
+		options: { verbose: true },
+		settingsManager: { getQuietStartup: () => false },
+		sessionManager: { getCwd: () => "/repo" },
+		session: {
+			promptTemplates: [],
+			resourceLoader: {
+				getAgentsFiles: () => ({ agentsFiles: [{ path: "/repo/AGENTS.md" }], diagnostics: [] }),
+				getSystemPromptSource: () => undefined,
+				getAppendSystemPromptSources: () => [],
+				getSkills: () => ({ skills: [], diagnostics: [] }),
+				getPrompts: () => ({ prompts: [], diagnostics: [] }),
+				getThemes: () => ({ themes: [], diagnostics: [] }),
+				getExtensions: () => ({ extensions: [], errors: [] }),
+			},
+			extensionRunner: {
+				getCommandDiagnostics: () => [],
+				getShortcutDiagnostics: () => [],
+				getRegisteredCommands: () => [],
+			},
+		},
+		getStartupExpansionState: () => false,
+		formatDisplayPath: (resourcePath) => resourcePath,
+		formatContextPath: (resourcePath) => resourcePath.replace("/repo/", ""),
+		getBuiltInCommandConflictDiagnostics: () => [],
+	};
+}
+
+describe("regression #5943: session_start transient UI", () => {
+	it("renders loaded resources before restored messages without stale entries", () => {
+		initTheme("dark", false);
+		const context = createLoadedResourcesContext();
+		const root = new Container();
+		root.addChild(context.loadedResourcesContainer);
+		root.addChild(context.chatContainer);
+		context.loadedResourcesContainer.addChild(new Text("stale resources", 0, 0));
+		context.chatContainer.addChild(new Text("restored message", 0, 0));
+
+		interactiveModePrototype.showLoadedResources.call(context);
+
+		const chatRendered = context.chatContainer.render(80).join("\n");
+		expect(chatRendered).toContain("restored message");
+		expect(chatRendered).not.toContain("[Context]");
+
+		const rendered = root.render(80).join("\n");
+		expect(rendered).not.toContain("stale resources");
+		expect(rendered.indexOf("[Context]")).toBeLessThan(rendered.indexOf("restored message"));
+	});
+
+	it("renders replacement session state before session_start handlers can notify", async () => {
+		const events: string[] = [];
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_start", (_event, ctx) => {
+						ctx.ui.notify("Hello Error", "error");
+					});
+				},
+			],
+		});
+
+		try {
+			const context: RebindContext = {
+				applyRuntimeSettings: () => events.push("apply"),
+				renderCurrentSessionState: () => events.push("render"),
+				bindCurrentSessionExtensions: async () => {
+					events.push("bind");
+					await harness.session.bindExtensions({
+						uiContext: createUiContext((message) => events.push(`notify:${message}`)),
+						mode: "tui",
+					});
+				},
+				subscribeToAgent: () => events.push("subscribe"),
+				updateAvailableProviderCount: async () => {},
+				updateEditorBorderColor: () => {},
+				updateTerminalTitle: () => {},
+			};
+
+			await interactiveModePrototype.rebindCurrentSession.call(context, { renderBeforeBind: true });
+
+			expect(events).toEqual(["apply", "render", "subscribe", "bind", "notify:Hello Error"]);
+		} finally {
+			harness.cleanup();
+		}
+	});
+
+	it("subscribes before replacement session_start handlers send messages", async () => {
+		const events: string[] = [];
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_start", () => {
+						pi.sendMessage({
+							customType: "session-start",
+							content: "custom from start",
+							display: true,
+						});
+					});
+				},
+			],
+		});
+
+		try {
+			const context: RebindContext = {
+				applyRuntimeSettings: () => {},
+				renderCurrentSessionState: () => events.push("render"),
+				bindCurrentSessionExtensions: async () => {
+					events.push("bind");
+					await harness.session.bindExtensions({
+						uiContext: createUiContext(() => {}),
+						mode: "tui",
+					});
+				},
+				subscribeToAgent: () => {
+					events.push("subscribe");
+					harness.session.subscribe((event) => {
+						if (event.type !== "message_start" && event.type !== "message_end") {
+							return;
+						}
+						events.push(`${event.type}:${event.message.role}:${getMessageText(event)}`);
+					});
+				},
+				updateAvailableProviderCount: async () => {},
+				updateEditorBorderColor: () => {},
+				updateTerminalTitle: () => {},
+			};
+
+			await interactiveModePrototype.rebindCurrentSession.call(context, { renderBeforeBind: true });
+
+			expect(events).toEqual([
+				"render",
+				"subscribe",
+				"bind",
+				"message_start:custom:custom from start",
+				"message_end:custom:custom from start",
+			]);
+		} finally {
+			harness.cleanup();
+		}
+	});
+
+	it("subscribes before replacement session_start handlers send user messages", async () => {
+		const events: string[] = [];
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_start", () => {
+						pi.sendUserMessage("user from start");
+					});
+				},
+			],
+		});
+		harness.setResponses([fauxAssistantMessage("assistant from start")]);
+
+		try {
+			const context: RebindContext = {
+				applyRuntimeSettings: () => {},
+				renderCurrentSessionState: () => events.push("render"),
+				bindCurrentSessionExtensions: async () => {
+					events.push("bind");
+					await harness.session.bindExtensions({
+						uiContext: createUiContext(() => {}),
+						mode: "tui",
+					});
+				},
+				subscribeToAgent: () => {
+					events.push("subscribe");
+					harness.session.subscribe((event) => {
+						if (event.type !== "message_start" && event.type !== "message_end") {
+							return;
+						}
+						events.push(`${event.type}:${event.message.role}:${getMessageText(event)}`);
+					});
+				},
+				updateAvailableProviderCount: async () => {},
+				updateEditorBorderColor: () => {},
+				updateTerminalTitle: () => {},
+			};
+
+			await interactiveModePrototype.rebindCurrentSession.call(context, { renderBeforeBind: true });
+			await harness.session.agent.waitForIdle();
+
+			expect(events.slice(0, 3)).toEqual(["render", "subscribe", "bind"]);
+			expect(events).toContain("message_start:user:user from start");
+			expect(events).toContain("message_end:user:user from start");
+			expect(events).toContain("message_end:assistant:assistant from start");
+		} finally {
+			harness.cleanup();
+		}
+	});
+
+	it("runs the reload render hook before reload session_start handlers can notify", async () => {
+		const events: string[] = [];
+		const beforeSessionStart = vi.fn(() => {
+			events.push("render");
+		});
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_start", (event, ctx) => {
+						events.push(`start:${event.reason}`);
+						ctx.ui.notify(`notify:${event.reason}`, "error");
+					});
+				},
+			],
+		});
+
+		try {
+			await harness.session.bindExtensions({
+				uiContext: createUiContext((message) => events.push(message)),
+				mode: "tui",
+			});
+			expect(events).toEqual(["start:startup", "notify:startup"]);
+
+			events.length = 0;
+			await harness.session.reload({ beforeSessionStart });
+
+			expect(beforeSessionStart).toHaveBeenCalledTimes(1);
+			expect(events).toEqual(["render", "start:reload", "notify:reload"]);
+		} finally {
+			harness.cleanup();
+		}
+	});
+
+	it("refreshes hideThinkingBlock before rebuilding chat during reload", async () => {
+		initTheme("dark", false);
+		const events: string[] = [];
+		let context: ReloadCommandContext;
+		context = createReloadCommandContext({
+			settingsManager: { getHideThinkingBlock: () => true },
+			session: {
+				reload: async (options) => {
+					events.push("reload");
+					await options?.beforeSessionStart?.();
+					events.push(`start:${context.hideThinkingBlock}`);
+				},
+			},
+			rebuildChatFromMessages: () => {
+				events.push(`rebuild:${context.hideThinkingBlock}`);
+			},
+		});
+
+		await interactiveModePrototype.handleReloadCommand.call(context);
+
+		expect(context.hideThinkingBlock).toBe(true);
+		expect(events).toEqual(["reload", "rebuild:true", "start:true"]);
+	});
+
+	it("keeps the reload blocker focused until async reload completes", async () => {
+		initTheme("dark", false);
+		const editor = {};
+		let focused: unknown;
+		let chatRestored = false;
+		let markReloadWaiting!: () => void;
+		let finishReload!: () => void;
+		const reloadWaiting = new Promise<void>((resolve) => {
+			markReloadWaiting = resolve;
+		});
+		const reloadFinished = new Promise<void>((resolve) => {
+			finishReload = resolve;
+		});
+
+		const context = createReloadCommandContext({
+			editor,
+			session: {
+				reload: async (options) => {
+					await options?.beforeSessionStart?.();
+					markReloadWaiting();
+					await reloadFinished;
+				},
+			},
+			ui: {
+				setFocus: (component) => {
+					focused = component;
+				},
+			},
+			rebuildChatFromMessages: () => {
+				chatRestored = true;
+			},
+		});
+
+		const reloadPromise = interactiveModePrototype.handleReloadCommand.call(context);
+		await reloadWaiting;
+
+		expect(chatRestored).toBe(true);
+		expect(focused).not.toBe(editor);
+
+		finishReload();
+		await reloadPromise;
+
+		expect(focused).toBe(editor);
+	});
+});

packages/coding-agent/test/suite/regressions/5996-session-name-newlines.test.ts

@@ -0,0 +1,40 @@
+import { afterEach, describe, expect, it } from "vitest";
+import type { ExtensionAPI } from "../../../src/index.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+describe("regression #5996: session names do not contain newlines", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("filters newlines when AgentSession.setSessionName is called", async () => {
+		const harness = await createHarness();
+		harnesses.push(harness);
+
+		harness.session.setSessionName("hello\nworld\r\nagain");
+
+		expect(harness.sessionManager.getSessionName()).toBe("hello world again");
+		expect(harness.eventsOfType("session_info_changed").map((event) => event.name)).toEqual(["hello world again"]);
+	});
+
+	it("filters newlines when an extension calls pi.setSessionName", async () => {
+		let api: ExtensionAPI | undefined;
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					api = pi;
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		api?.setSessionName("from\nextension");
+
+		expect(harness.sessionManager.getSessionName()).toBe("from extension");
+		expect(harness.eventsOfType("session_info_changed").map((event) => event.name)).toEqual(["from extension"]);
+	});
+});

packages/coding-agent/test/suite/regressions/5998-blocked-tool-terminate.test.ts

@@ -0,0 +1,53 @@
+import type { AgentTool } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, getAssistantTexts, type Harness } from "../harness.ts";
+
+describe("#5998 blocked tool termination", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("lets a tool_call handler terminate the run after blocking execution", async () => {
+		const echoTool: AgentTool = {
+			name: "echo",
+			label: "Echo",
+			description: "Echo text back",
+			parameters: Type.Object({ text: Type.String() }),
+			execute: async () => {
+				throw new Error("tool should have been blocked");
+			},
+		};
+		const harness = await createHarness({
+			tools: [echoTool],
+			extensionFactories: [
+				(pi) => {
+					pi.on("tool_call", async () => ({
+						block: true,
+						reason: "Blocked by terminating policy",
+						terminate: true,
+					}));
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage([fauxToolCall("echo", { text: "hello" })], { stopReason: "toolUse" }),
+			fauxAssistantMessage("should not run"),
+		]);
+
+		await harness.session.prompt("hi");
+
+		expect(harness.getPendingResponseCount()).toBe(1);
+		expect(getAssistantTexts(harness)).not.toContain("should not run");
+		expect(harness.eventsOfType("tool_execution_end")[0]?.result).toHaveProperty("terminate", true);
+		expect(
+			harness.session.messages.find((message) => message.role === "toolResult" && message.isError),
+		).toBeDefined();
+	});
+});

packages/coding-agent/test/suite/regressions/6019-explicit-provider-retry-message.test.ts

@@ -0,0 +1,31 @@
+import { fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { describe, expect, it } from "vitest";
+import { createHarness } from "../harness.ts";
+
+const openAIExplicitRetryMessage =
+	"An error occurred while processing your request. You can retry your request, or contact us through our help center at help.openai.com if the error persists. Please include the request ID req_******** in your message.";
+const bedrockExplicitRetryMessage =
+	'{"message":"The system encountered an unexpected error during processing. Try your request again."}';
+
+describe("regression: issue 6019 explicit provider retry messages", () => {
+	it.each([
+		["openai", openAIExplicitRetryMessage],
+		["bedrock", bedrockExplicitRetryMessage],
+	])("retries %s explicit retry guidance", async (_provider, errorMessage) => {
+		const harness = await createHarness({ settings: { retry: { enabled: true, maxRetries: 3, baseDelayMs: 1 } } });
+		try {
+			harness.setResponses([
+				fauxAssistantMessage("", { stopReason: "error", errorMessage }),
+				fauxAssistantMessage("recovered"),
+			]);
+
+			await harness.session.prompt("test");
+
+			expect(harness.faux.state.callCount).toBe(2);
+			expect(harness.eventsOfType("auto_retry_start").map((event) => event.errorMessage)).toEqual([errorMessage]);
+			expect(harness.eventsOfType("auto_retry_end").map((event) => event.success)).toEqual([true]);
+		} finally {
+			harness.cleanup();
+		}
+	});
+});

packages/coding-agent/test/suite/regressions/6104-find-root-relativization.test.ts

@@ -0,0 +1,91 @@
+import { posix, win32 } from "node:path";
+import { describe, expect, it } from "vitest";
+import { createFindToolDefinition, relativizeFindResultPath } from "../../../src/core/tools/find.ts";
+
+/**
+ * Regression test for https://github.com/earendil-works/pi/issues/6104
+ *
+ * path.resolve() preserves a trailing separator when resolving to a root path,
+ * such as POSIX / or Windows I:\\. The find tool used to slice absolute
+ * results at searchPath.length + 1, which dropped the first character of the
+ * first path segment for root searches. Windows directory results that ended in
+ * backslash also gained an extra slash.
+ */
+describe("issue #6104 find relativizes root search paths", () => {
+	describe("Windows drive root", () => {
+		const searchRoot = "I:\\";
+
+		it("preserves the first segment and emits one trailing slash for fd directory output", () => {
+			expect(relativizeFindResultPath("I:\\AI\\Models\\TextGen\\gemma4\\", searchRoot, win32)).toBe(
+				"AI/Models/TextGen/gemma4/",
+			);
+		});
+
+		it("handles fd output that uses forward slashes under a drive root", () => {
+			expect(relativizeFindResultPath("I:/AI/Models/TextGen/gemma4/", searchRoot, win32)).toBe(
+				"AI/Models/TextGen/gemma4/",
+			);
+		});
+
+		it("keeps deeper search paths unchanged", () => {
+			expect(relativizeFindResultPath("I:\\AI\\Models\\", "I:\\AI", win32)).toBe("Models/");
+		});
+
+		it("does not relativize a sibling directory that shares a name prefix", () => {
+			expect(relativizeFindResultPath("I:\\AI\\Models2\\file.txt", "I:\\AI\\Models", win32)).toBe(
+				"../Models2/file.txt",
+			);
+		});
+
+		it("normalizes relative custom-glob results without corrupting them", () => {
+			expect(relativizeFindResultPath("AI\\Models\\TextGen\\gemma4\\", searchRoot, win32)).toBe(
+				"AI/Models/TextGen/gemma4/",
+			);
+		});
+	});
+
+	describe("POSIX root", () => {
+		it("preserves the first segment for files under /", () => {
+			expect(relativizeFindResultPath("/home/user/file.txt", "/", posix)).toBe("home/user/file.txt");
+		});
+
+		it("preserves the first segment and one trailing slash for directories under /", () => {
+			expect(relativizeFindResultPath("/home/user/project/", "/", posix)).toBe("home/user/project/");
+		});
+
+		it("preserves backslashes in POSIX filenames", () => {
+			expect(relativizeFindResultPath("/home/user/file\\", "/home/user", posix)).toBe("file\\");
+		});
+	});
+
+	describe("absolute results outside the search path", () => {
+		it("falls back to path.relative when the absolute paths do not share a prefix", () => {
+			expect(relativizeFindResultPath("/tmp/results/file.txt", "/workspace/project", posix)).toBe(
+				"../../tmp/results/file.txt",
+			);
+		});
+
+		it("keeps a trailing slash on directories resolved through path.relative", () => {
+			expect(relativizeFindResultPath("/tmp/results/dir/", "/workspace/project", posix)).toBe(
+				"../../tmp/results/dir/",
+			);
+		});
+	});
+
+	describe("through the find tool", () => {
+		it("relativizes custom glob results against a root search path", async () => {
+			const def = createFindToolDefinition("/", {
+				operations: {
+					exists: () => true,
+					glob: () => ["/home/user/project/", "/home/user/project/file.txt"],
+				},
+			});
+			// The find tool implementation does not touch ctx; pass a minimal stub.
+			const ctx = {} as Parameters<typeof def.execute>[4];
+			const result = (await def.execute("call-1", { pattern: "**" }, undefined, undefined, ctx)) as {
+				content: Array<{ type: string; text?: string }>;
+			};
+			expect(result.content[0]?.text).toBe("home/user/project/\nhome/user/project/file.txt");
+		});
+	});
+});

packages/coding-agent/test/suite/regressions/6162-extension-active-tools-next-turn.test.ts

@@ -0,0 +1,192 @@
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { describe, expect, it } from "vitest";
+import type { ExtensionFactory } from "../../../src/index.ts";
+import { createHarness } from "../harness.ts";
+
+describe("extension active tools next-turn refresh", () => {
+	it("applies pi.setActiveTools before the next provider request in the same run", async () => {
+		const extensionFactories: ExtensionFactory[] = [
+			(pi) => {
+				pi.registerTool({
+					name: "switch_tools",
+					label: "Switch Tools",
+					description: "Switch the active extension tool set",
+					promptSnippet: "Switch to the next extension tool",
+					parameters: Type.Object({}),
+					execute: async () => {
+						pi.setActiveTools(["after_switch"]);
+						return {
+							content: [{ type: "text", text: "switched" }],
+							details: {},
+						};
+					},
+				});
+
+				pi.registerTool({
+					name: "after_switch",
+					label: "After Switch",
+					description: "Tool that should be available after switching",
+					promptSnippet: "Run after the active tool set changes",
+					parameters: Type.Object({}),
+					execute: async () => ({
+						content: [{ type: "text", text: "after" }],
+						details: {},
+					}),
+				});
+			},
+		];
+		const harness = await createHarness({
+			extensionFactories,
+		});
+
+		try {
+			harness.session.setActiveToolsByName(["switch_tools"]);
+
+			const providerToolNames: string[][] = [];
+			harness.setResponses([
+				(context) => {
+					providerToolNames.push((context.tools ?? []).map((tool) => tool.name).sort());
+					return fauxAssistantMessage(fauxToolCall("switch_tools", {}), { stopReason: "toolUse" });
+				},
+				(context) => {
+					providerToolNames.push((context.tools ?? []).map((tool) => tool.name).sort());
+					return fauxAssistantMessage("done");
+				},
+			]);
+
+			expect(harness.session.getActiveToolNames()).toEqual(["switch_tools"]);
+
+			await harness.session.prompt("start");
+
+			expect(harness.session.getActiveToolNames()).toEqual(["after_switch"]);
+			expect(providerToolNames).toEqual([["switch_tools"], ["after_switch"]]);
+		} finally {
+			harness.cleanup();
+		}
+	});
+
+	it("records additive active tool changes on the current tool result", async () => {
+		const extensionFactories: ExtensionFactory[] = [
+			(pi) => {
+				pi.registerTool({
+					name: "load_more_tools",
+					label: "Load More Tools",
+					description: "Load more tools",
+					parameters: Type.Object({}),
+					execute: async () => {
+						pi.setActiveTools([...pi.getActiveTools(), "after_load"]);
+						return {
+							content: [{ type: "text", text: "loaded" }],
+							details: {},
+						};
+					},
+				});
+
+				pi.registerTool({
+					name: "after_load",
+					label: "After Load",
+					description: "Tool available after loading",
+					parameters: Type.Object({}),
+					execute: async () => ({
+						content: [{ type: "text", text: "after" }],
+						details: {},
+					}),
+				});
+			},
+		];
+		const harness = await createHarness({ extensionFactories });
+
+		try {
+			harness.session.setActiveToolsByName(["load_more_tools"]);
+
+			const addedToolNames: string[][] = [];
+			harness.setResponses([
+				() => fauxAssistantMessage(fauxToolCall("load_more_tools", {}), { stopReason: "toolUse" }),
+				(context) => {
+					addedToolNames.push(
+						context.messages
+							.filter((message) => message.role === "toolResult")
+							.flatMap((message) => message.addedToolNames ?? []),
+					);
+					return fauxAssistantMessage("done");
+				},
+			]);
+
+			await harness.session.prompt("start");
+
+			expect(harness.session.getActiveToolNames()).toEqual(["load_more_tools", "after_load"]);
+			expect(addedToolNames).toEqual([["after_load"]]);
+		} finally {
+			harness.cleanup();
+		}
+	});
+
+	it("preserves before_agent_start system prompt overrides when tools change mid-run", async () => {
+		const extensionFactories: ExtensionFactory[] = [
+			(pi) => {
+				pi.on("before_agent_start", async (event) => ({
+					systemPrompt: `${event.systemPrompt}\n\nkeep this run override`,
+				}));
+
+				pi.registerTool({
+					name: "switch_tools",
+					label: "Switch Tools",
+					description: "Switch the active extension tool set",
+					promptSnippet: "Switch to the next extension tool",
+					parameters: Type.Object({}),
+					execute: async () => {
+						pi.setActiveTools(["after_switch"]);
+						return {
+							content: [{ type: "text", text: "switched" }],
+							details: {},
+						};
+					},
+				});
+
+				pi.registerTool({
+					name: "after_switch",
+					label: "After Switch",
+					description: "Tool that should be available after switching",
+					promptSnippet: "Run after the active tool set changes",
+					parameters: Type.Object({}),
+					execute: async () => ({
+						content: [{ type: "text", text: "after" }],
+						details: {},
+					}),
+				});
+			},
+		];
+		const harness = await createHarness({
+			extensionFactories,
+		});
+
+		try {
+			harness.session.setActiveToolsByName(["switch_tools"]);
+
+			const providerSystemPrompts: string[] = [];
+			const providerToolNames: string[][] = [];
+			harness.setResponses([
+				(context) => {
+					providerSystemPrompts.push(context.systemPrompt ?? "");
+					providerToolNames.push((context.tools ?? []).map((tool) => tool.name).sort());
+					return fauxAssistantMessage(fauxToolCall("switch_tools", {}), { stopReason: "toolUse" });
+				},
+				(context) => {
+					providerSystemPrompts.push(context.systemPrompt ?? "");
+					providerToolNames.push((context.tools ?? []).map((tool) => tool.name).sort());
+					return fauxAssistantMessage("done");
+				},
+			]);
+
+			await harness.session.prompt("start");
+
+			expect(providerToolNames).toEqual([["switch_tools"], ["after_switch"]]);
+			expect(providerSystemPrompts).toHaveLength(2);
+			expect(providerSystemPrompts[0]).toContain("keep this run override");
+			expect(providerSystemPrompts[1]).toContain("keep this run override");
+		} finally {
+			harness.cleanup();
+		}
+	});
+});

packages/coding-agent/test/suite/regressions/6260-inline-extension-naming.test.ts

@@ -0,0 +1,119 @@
+import { existsSync, mkdirSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { DefaultResourceLoader } from "../../../src/core/resource-loader.ts";
+import type { ExtensionAPI } from "../../../src/index.ts";
+
+const noop: (pi: ExtensionAPI) => void = () => {};
+
+describe("inline extension naming", () => {
+	const roots: string[] = [];
+
+	function fixture(name: string) {
+		const root = join(tmpdir(), `pi-inline-naming-${name}-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		const cwd = join(root, "project");
+		const agentDir = join(root, "agent");
+		mkdirSync(cwd, { recursive: true });
+		mkdirSync(agentDir, { recursive: true });
+		roots.push(root);
+		return { root, cwd, agentDir };
+	}
+
+	beforeEach(() => {
+		roots.length = 0;
+	});
+
+	afterEach(() => {
+		while (roots.length > 0) {
+			const root = roots.pop();
+			if (root && existsSync(root)) {
+				rmSync(root, { recursive: true, force: true });
+			}
+		}
+	});
+
+	it("displays bare factories as <inline:N>", async () => {
+		const { cwd, agentDir } = fixture("bare");
+		const loader = new DefaultResourceLoader({
+			cwd,
+			agentDir,
+			noSkills: true,
+			noPromptTemplates: true,
+			noThemes: true,
+			extensionFactories: [noop, noop],
+		});
+
+		await loader.reload();
+
+		const result = loader.getExtensions();
+
+		expect(result.extensions).toHaveLength(2);
+		expect(result.extensions[0].path).toBe("<inline:1>");
+		expect(result.extensions[1].path).toBe("<inline:2>");
+	});
+
+	it("displays named wrappers as <inline:name>", async () => {
+		const { cwd, agentDir } = fixture("named");
+		const loader = new DefaultResourceLoader({
+			cwd,
+			agentDir,
+			noSkills: true,
+			noPromptTemplates: true,
+			noThemes: true,
+			extensionFactories: [
+				{ name: "my-provider", factory: noop },
+				{ name: "my-commands", factory: noop },
+			],
+		});
+
+		await loader.reload();
+
+		const result = loader.getExtensions();
+
+		expect(result.extensions).toHaveLength(2);
+		expect(result.extensions[0].path).toBe("<inline:my-provider>");
+		expect(result.extensions[1].path).toBe("<inline:my-commands>");
+	});
+
+	it("preserves hidden state for named factories", async () => {
+		const { cwd, agentDir } = fixture("hidden");
+		const loader = new DefaultResourceLoader({
+			cwd,
+			agentDir,
+			noSkills: true,
+			noPromptTemplates: true,
+			noThemes: true,
+			extensionFactories: [{ name: "built-in", factory: noop, hidden: true }],
+		});
+
+		await loader.reload();
+
+		const result = loader.getExtensions();
+
+		expect(result.extensions).toHaveLength(1);
+		expect(result.extensions[0].path).toBe("<inline:built-in>");
+		expect(result.extensions[0].hidden).toBe(true);
+	});
+
+	it("supports mixed bare and named factories", async () => {
+		const { cwd, agentDir } = fixture("mixed");
+		const loader = new DefaultResourceLoader({
+			cwd,
+			agentDir,
+			noSkills: true,
+			noPromptTemplates: true,
+			noThemes: true,
+			extensionFactories: [noop, { name: "named-ext", factory: noop }, noop],
+		});
+
+		await loader.reload();
+
+		const result = loader.getExtensions();
+
+		expect(result.extensions).toHaveLength(3);
+		expect(result.extensions[0].path).toBe("<inline:1>");
+		expect(result.extensions[1].path).toBe("<inline:named-ext>");
+		expect(result.extensions[2].path).toBe("<inline:3>");
+	});
+});

packages/coding-agent/test/suite/regressions/6324-branch-summary-ambient-auth.test.ts

@@ -0,0 +1,62 @@
+import { createAssistantMessageEventStream } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import { assistantMsg, userMsg } from "../../utilities.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+describe("issue #6324 branch summary ambient auth", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("summarizes tree branches when request auth has no API key", async () => {
+		const harness = await createHarness({ withConfiguredAuth: false });
+		harnesses.push(harness);
+
+		let streamCallCount = 0;
+		harness.session.agent.streamFunction = (model, _context, options) => {
+			streamCallCount++;
+			expect(options?.apiKey).toBeUndefined();
+
+			const stream = createAssistantMessageEventStream();
+			stream.push({
+				type: "done",
+				reason: "stop",
+				message: {
+					role: "assistant",
+					content: [{ type: "text", text: "branch summary text" }],
+					api: model.api,
+					provider: model.provider,
+					model: model.id,
+					usage: {
+						input: 1,
+						output: 1,
+						cacheRead: 0,
+						cacheWrite: 0,
+						totalTokens: 2,
+						cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0.25 },
+					},
+					stopReason: "stop",
+					timestamp: Date.now(),
+				},
+			});
+			return stream;
+		};
+
+		const targetId = harness.sessionManager.appendMessage(userMsg("first branch"));
+		harness.sessionManager.appendMessage(assistantMsg("first reply"));
+		harness.sessionManager.appendMessage(userMsg("abandoned branch work"));
+		harness.sessionManager.appendMessage(assistantMsg("abandoned reply"));
+
+		const result = await harness.session.navigateTree(targetId, { summarize: true });
+
+		expect(result.cancelled).toBe(false);
+		expect(streamCallCount).toBe(1);
+		expect(result.summaryEntry?.type).toBe("branch_summary");
+		expect(result.summaryEntry?.summary).toContain("branch summary text");
+		expect(result.summaryEntry?.usage?.cost.total).toBe(0.25);
+	});
+});

packages/coding-agent/test/suite/regressions/6363-agent-settled-event.test.ts

@@ -0,0 +1,158 @@
+import type { AgentTool } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, getUserTexts, type Harness } from "../harness.ts";
+
+function createWaitTool(released: Promise<void>): AgentTool {
+	return {
+		name: "wait",
+		label: "Wait",
+		description: "Wait until released",
+		parameters: Type.Object({}),
+		execute: async () => {
+			await released;
+			return { content: [{ type: "text", text: "released" }], details: {} };
+		},
+	};
+}
+
+describe("regression #6363: agent settled event and idle waiting", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("emits one agent_settled event after automatic retry finishes", async () => {
+		const extensionEvents: string[] = [];
+		const publicEvents: string[] = [];
+		const harness = await createHarness({
+			settings: { retry: { enabled: true, maxRetries: 3, baseDelayMs: 1 } },
+			extensionFactories: [
+				(pi) => {
+					pi.on("agent_end", () => {
+						extensionEvents.push("agent_end");
+					});
+					pi.on("agent_settled", (_event, ctx) => {
+						extensionEvents.push(`agent_settled:${ctx.isIdle()}`);
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.session.subscribe((event) => {
+			if (event.type === "agent_settled") {
+				publicEvents.push("agent_settled");
+			}
+		});
+		harness.setResponses([
+			fauxAssistantMessage("", { stopReason: "error", errorMessage: "overloaded_error" }),
+			fauxAssistantMessage("recovered"),
+		]);
+
+		await harness.session.prompt("test");
+
+		expect(harness.eventsOfType("agent_end").map((event) => event.willRetry)).toEqual([true, false]);
+		expect(harness.eventsOfType("agent_settled")).toHaveLength(1);
+		expect(extensionEvents).toEqual(["agent_end", "agent_end", "agent_settled:true"]);
+		expect(publicEvents).toEqual(["agent_settled"]);
+	});
+
+	it("settles only after follow-ups queued by agent_end handlers run", async () => {
+		let queuedFollowUp = false;
+		const settledIdleStates: boolean[] = [];
+		const harness = await createHarness({
+			extensionFactories: [
+				(pi) => {
+					pi.on("agent_end", () => {
+						if (queuedFollowUp) return;
+						queuedFollowUp = true;
+						pi.sendUserMessage("status follow-up", { deliverAs: "followUp" });
+					});
+					pi.on("agent_settled", (_event, ctx) => {
+						settledIdleStates.push(ctx.isIdle());
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage("first"), fauxAssistantMessage("second")]);
+
+		await harness.session.prompt("hello");
+
+		expect(getUserTexts(harness)).toEqual(["hello", "status follow-up"]);
+		expect(harness.eventsOfType("agent_end")).toHaveLength(2);
+		expect(harness.eventsOfType("agent_settled")).toHaveLength(1);
+		expect(settledIdleStates).toEqual([true]);
+	});
+
+	it("extension command waitForIdle waits for session-level settlement", async () => {
+		let releaseTool = () => {};
+		const released = new Promise<void>((resolve) => {
+			releaseTool = resolve;
+		});
+		let markCommandStarted = () => {};
+		const commandStarted = new Promise<void>((resolve) => {
+			markCommandStarted = resolve;
+		});
+		const commandResults: boolean[] = [];
+		const harness = await createHarness({
+			tools: [createWaitTool(released)],
+			extensionFactories: [
+				(pi) => {
+					pi.registerCommand("after-idle", {
+						description: "Wait for idle",
+						handler: async (_args, ctx) => {
+							markCommandStarted();
+							await ctx.waitForIdle();
+							commandResults.push(ctx.isIdle());
+						},
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		await harness.session.bindExtensions({
+			commandContextActions: {
+				waitForIdle: () => harness.session.waitForIdle(),
+				newSession: async () => ({ cancelled: false }),
+				fork: async () => ({ cancelled: false }),
+				navigateTree: async () => ({ cancelled: false }),
+				switchSession: async () => ({ cancelled: false }),
+				reload: async () => {},
+			},
+		});
+		const toolStarted = new Promise<void>((resolve) => {
+			const unsubscribe = harness.session.subscribe((event) => {
+				if (event.type === "tool_execution_start" && event.toolName === "wait") {
+					unsubscribe();
+					resolve();
+				}
+			});
+		});
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("wait", {}), { stopReason: "toolUse" }),
+			fauxAssistantMessage("done"),
+		]);
+
+		const promptPromise = harness.session.prompt("start");
+		await toolStarted;
+		const commandPromise = harness.session.prompt("/after-idle");
+		await commandStarted;
+		let commandFinished = false;
+		void commandPromise.then(() => {
+			commandFinished = true;
+		});
+		await new Promise((resolve) => setTimeout(resolve, 0));
+		expect(commandFinished).toBe(false);
+
+		releaseTool();
+		await Promise.all([promptPromise, commandPromise]);
+
+		expect(commandResults).toEqual([true]);
+		expect(harness.eventsOfType("agent_settled")).toHaveLength(1);
+	});
+});

packages/coding-agent/test/suite/regressions/6596-taskkill-enoent.test.ts

@@ -0,0 +1,52 @@
+import type { ChildProcess } from "node:child_process";
+import { EventEmitter } from "node:events";
+import { join } from "node:path";
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+const { spawnMock } = vi.hoisted(() => ({ spawnMock: vi.fn() }));
+
+vi.mock("child_process", async (importOriginal) => {
+	const actual = await importOriginal<typeof import("child_process")>();
+	return { ...actual, spawn: spawnMock };
+});
+
+import { killProcessTree } from "../../../src/utils/shell.ts";
+
+function withWindowsPlatform(test: () => void): void {
+	const platformDescriptor = Object.getOwnPropertyDescriptor(process, "platform");
+	try {
+		Object.defineProperty(process, "platform", { configurable: true, value: "win32" });
+		test();
+	} finally {
+		if (platformDescriptor) Object.defineProperty(process, "platform", platformDescriptor);
+	}
+}
+
+afterEach(() => {
+	spawnMock.mockReset();
+});
+
+describe("issue #6596 taskkill spawn failures", () => {
+	it("uses System32 taskkill and consumes its asynchronous spawn error", () => {
+		const child = new EventEmitter() as ChildProcess;
+		const previousSystemRoot = process.env.SystemRoot;
+		process.env.SystemRoot = "C:\\CustomWindows";
+		spawnMock.mockReturnValue(child);
+
+		try {
+			withWindowsPlatform(() => {
+				killProcessTree(1234);
+			});
+		} finally {
+			if (previousSystemRoot === undefined) delete process.env.SystemRoot;
+			else process.env.SystemRoot = previousSystemRoot;
+		}
+
+		expect(spawnMock).toHaveBeenCalledWith(
+			join("C:\\CustomWindows", "System32", "taskkill.exe"),
+			["/F", "/T", "/PID", "1234"],
+			{ detached: true, stdio: "ignore", windowsHide: true },
+		);
+		expect(() => child.emit("error", new Error("spawn taskkill ENOENT"))).not.toThrow();
+	});
+});

packages/coding-agent/test/suite/regressions/6647-compaction-retries-transient-stream-drop.test.ts

@@ -0,0 +1,192 @@
+import type { StreamFn } from "@earendil-works/pi-agent-core";
+import { type AssistantMessage, createAssistantMessageEventStream, fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, type Harness } from "../harness.ts";
+
+/**
+ * Regression for #6647: compaction runs a single non-retried summarization call, so a
+ * transient mid-stream socket death (`terminated`) failed the whole compaction.
+ * Verifies that summarization now reuses `settings.retry` (bounded retries with
+ * exponential backoff gated on isRetryableAssistantError), emits
+ * `summarization_retry_*` events, and that aborts / non-retryable errors are not retried.
+ */
+describe("#6647 compaction retries transient summarization failures", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	function createUsage(totalTokens: number) {
+		return {
+			input: totalTokens,
+			output: 0,
+			cacheRead: 0,
+			cacheWrite: 0,
+			totalTokens,
+			cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+		};
+	}
+
+	function seedCompactableSession(harness: Harness): void {
+		harness.settingsManager.applyOverrides({ compaction: { keepRecentTokens: 1 } });
+		const now = Date.now();
+		harness.sessionManager.appendMessage({
+			role: "user",
+			content: [{ type: "text", text: "message to compact" }],
+			timestamp: now - 1000,
+		});
+		const model = harness.getModel();
+		const assistant: AssistantMessage = {
+			...fauxAssistantMessage("", { stopReason: "stop", timestamp: now - 500 }),
+			api: model.api,
+			provider: model.provider,
+			model: model.id,
+			usage: createUsage(100),
+		};
+		assistant.content = [{ type: "text", text: "assistant response to compact" }];
+		harness.sessionManager.appendMessage(assistant);
+		harness.session.agent.state.messages = harness.sessionManager.buildSessionContext().messages;
+	}
+
+	/** streamFn that responds with the given sequence of assistant messages across calls. */
+	function useScriptedStreamFn(harness: Harness, script: AssistantMessage[]): () => number {
+		let callCount = 0;
+		const streamFunction: StreamFn = (model) => {
+			const message = script[callCount] ?? script[script.length - 1]!;
+			callCount++;
+			const stream = createAssistantMessageEventStream();
+			queueMicrotask(() => {
+				const response = { ...message, api: model.api, provider: model.provider, model: model.id };
+				if (response.stopReason === "pending") {
+					const error: AssistantMessage = {
+						...response,
+						stopReason: "error",
+						errorMessage: "Scripted response ended without a stop reason",
+					};
+					stream.push({ type: "error", reason: "error", error });
+				} else if (response.stopReason === "error" || response.stopReason === "aborted") {
+					stream.push({ type: "error", reason: response.stopReason, error: response });
+				} else {
+					stream.push({ type: "done", reason: response.stopReason, message: response });
+				}
+			});
+			return stream;
+		};
+		harness.session.agent.streamFunction = streamFunction;
+		return () => callCount;
+	}
+
+	it("retries a transient `terminated` summarization error and compacts successfully", async () => {
+		const harness = await createHarness({ withConfiguredAuth: false });
+		harnesses.push(harness);
+		seedCompactableSession(harness);
+		harness.settingsManager.applyOverrides({ retry: { enabled: true, maxRetries: 3, baseDelayMs: 0 } });
+
+		const model = harness.getModel();
+		const error = (errorMessage: string): AssistantMessage => ({
+			...fauxAssistantMessage("", { stopReason: "error", errorMessage }),
+			usage: createUsage(10),
+		});
+		const success: AssistantMessage = {
+			...fauxAssistantMessage("recovered summary"),
+			usage: createUsage(10),
+		};
+		const getCallCount = useScriptedStreamFn(harness, [error("terminated"), error("terminated"), success]);
+
+		const result = await harness.session.compact();
+
+		expect(result.summary).toContain("recovered summary");
+		expect(getCallCount()).toBe(3); // 1 initial + 2 retries
+		const starts = harness.eventsOfType("summarization_retry_scheduled");
+		const ends = harness.eventsOfType("summarization_retry_finished");
+		expect(starts).toHaveLength(2);
+		expect(ends).toHaveLength(1);
+		expect(starts[0]).toMatchObject({ attempt: 1, maxAttempts: 3, errorMessage: "terminated" });
+		expect(starts[1]).toMatchObject({ attempt: 2, maxAttempts: 3 });
+		expect(ends[0]).toMatchObject({ type: "summarization_retry_finished" });
+		// model.* referenced to keep imports honest
+		expect(model.id).toBeTruthy();
+	});
+
+	it("does not retry a non-retryable error (insufficient_quota)", async () => {
+		const harness = await createHarness({ withConfiguredAuth: false });
+		harnesses.push(harness);
+		seedCompactableSession(harness);
+		harness.settingsManager.applyOverrides({ retry: { enabled: true, maxRetries: 3, baseDelayMs: 0 } });
+
+		const error: AssistantMessage = {
+			...fauxAssistantMessage("", { stopReason: "error", errorMessage: "insufficient_quota" }),
+			usage: createUsage(10),
+		};
+		const getCallCount = useScriptedStreamFn(harness, [error]);
+
+		await expect(harness.session.compact()).rejects.toThrow("insufficient_quota");
+		expect(getCallCount()).toBe(1);
+		expect(harness.eventsOfType("summarization_retry_scheduled")).toHaveLength(0);
+	});
+
+	it("does not retry when retry is disabled", async () => {
+		const harness = await createHarness({ withConfiguredAuth: false });
+		harnesses.push(harness);
+		seedCompactableSession(harness);
+		harness.settingsManager.applyOverrides({ retry: { enabled: false, maxRetries: 3, baseDelayMs: 0 } });
+
+		const error: AssistantMessage = {
+			...fauxAssistantMessage("", { stopReason: "error", errorMessage: "terminated" }),
+			usage: createUsage(10),
+		};
+		const getCallCount = useScriptedStreamFn(harness, [error]);
+
+		await expect(harness.session.compact()).rejects.toThrow("terminated");
+		expect(getCallCount()).toBe(1);
+		expect(harness.eventsOfType("summarization_retry_scheduled")).toHaveLength(0);
+	});
+
+	it("stops retrying after maxRetries and reports failure", async () => {
+		const harness = await createHarness({ withConfiguredAuth: false });
+		harnesses.push(harness);
+		seedCompactableSession(harness);
+		harness.settingsManager.applyOverrides({ retry: { enabled: true, maxRetries: 2, baseDelayMs: 0 } });
+
+		const error: AssistantMessage = {
+			...fauxAssistantMessage("", { stopReason: "error", errorMessage: "terminated" }),
+			usage: createUsage(10),
+		};
+		const getCallCount = useScriptedStreamFn(harness, [error, error, error]);
+
+		await expect(harness.session.compact()).rejects.toThrow("terminated");
+		expect(getCallCount()).toBe(3); // 1 initial + 2 retries
+		const starts = harness.eventsOfType("summarization_retry_scheduled");
+		const ends = harness.eventsOfType("summarization_retry_finished");
+		expect(starts).toHaveLength(2);
+		expect(ends).toHaveLength(1);
+		expect(ends[0]).toMatchObject({ type: "summarization_retry_finished" });
+	});
+
+	it("aborts an in-flight retry backoff via abortCompaction", async () => {
+		const harness = await createHarness({ withConfiguredAuth: false });
+		harnesses.push(harness);
+		seedCompactableSession(harness);
+		harness.settingsManager.applyOverrides({ retry: { enabled: true, maxRetries: 5, baseDelayMs: 30_000 } });
+
+		const error: AssistantMessage = {
+			...fauxAssistantMessage("", { stopReason: "error", errorMessage: "terminated" }),
+			usage: createUsage(10),
+		};
+		useScriptedStreamFn(harness, [error, error, error]);
+
+		const compactPromise = harness.session.compact();
+		// Let the first error resolve and the retry backoff sleep start.
+		await new Promise((resolve) => setTimeout(resolve, 0));
+		harness.session.abortCompaction();
+
+		// The aborted retry backoff is normalized to an aborted assistant message,
+		// which compaction classifies as aborted.
+		await expect(compactPromise).rejects.toThrow();
+		const compactionEnd = harness.eventsOfType("compaction_end").at(-1);
+		expect(compactionEnd).toMatchObject({ aborted: true });
+	});
+});

packages/coding-agent/test/suite/regressions/6768-copilot-compaction-base-url.test.ts

@@ -0,0 +1,114 @@
+import {
+	type AssistantMessage,
+	createAssistantMessageEventStream,
+	fauxAssistantMessage,
+	type Model,
+	type Provider,
+} from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, type Harness } from "../harness.ts";
+
+const INDIVIDUAL_BASE_URL = "https://api.individual.githubcopilot.com";
+const ENTERPRISE_BASE_URL = "https://api.enterprise.githubcopilot.com";
+
+function seedCompactableSession(harness: Harness): void {
+	harness.settingsManager.applyOverrides({ compaction: { keepRecentTokens: 1 } });
+	const now = Date.now();
+	harness.sessionManager.appendMessage({
+		role: "user",
+		content: [{ type: "text", text: "message to compact" }],
+		timestamp: now - 1000,
+	});
+	const model = harness.getModel();
+	const assistant: AssistantMessage = {
+		...fauxAssistantMessage("assistant response to compact", { timestamp: now - 500 }),
+		api: model.api,
+		provider: model.provider,
+		model: model.id,
+		usage: {
+			input: 100,
+			output: 0,
+			cacheRead: 0,
+			cacheWrite: 0,
+			totalTokens: 100,
+			cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+		},
+	};
+	harness.sessionManager.appendMessage(assistant);
+	harness.session.agent.state.messages = harness.sessionManager.buildSessionContext().messages;
+}
+
+describe("issue #6768 Copilot compaction base URL", () => {
+	let harness: Harness | undefined;
+
+	afterEach(() => {
+		harness?.cleanup();
+		harness = undefined;
+	});
+
+	it("uses the auth-resolved base URL through the SDK-style stream wrapper", async () => {
+		harness = await createHarness();
+		seedCompactableSession(harness);
+		const catalogModel = { ...harness.getModel(), baseUrl: INDIVIDUAL_BASE_URL };
+		harness.session.agent.state.model = catalogModel;
+
+		let requestBaseUrl: string | undefined;
+		const respond = (requestModel: Model<string>) => {
+			requestBaseUrl = requestModel.baseUrl;
+			const stream = createAssistantMessageEventStream();
+			stream.push({
+				type: "done",
+				reason: "stop",
+				message: {
+					...fauxAssistantMessage("summary"),
+					api: requestModel.api,
+					provider: requestModel.provider,
+					model: requestModel.id,
+				},
+			});
+			return stream;
+		};
+		const provider: Provider<string> = {
+			id: catalogModel.provider,
+			name: "Copilot regression provider",
+			baseUrl: INDIVIDUAL_BASE_URL,
+			auth: {
+				apiKey: {
+					name: "Copilot token",
+					resolve: async ({ credential }) =>
+						credential?.key ? { auth: { apiKey: credential.key }, source: "explicit token" } : undefined,
+				},
+				oauth: {
+					name: "Copilot OAuth",
+					login: async () => {
+						throw new Error("unused");
+					},
+					refresh: async (credential) => credential,
+					toAuth: async (credential) => ({
+						apiKey: credential.access,
+						baseUrl: ENTERPRISE_BASE_URL,
+					}),
+				},
+			},
+			getModels: () => [catalogModel],
+			stream: (requestModel) => respond(requestModel),
+			streamSimple: (requestModel) => respond(requestModel),
+		};
+
+		await harness.authStorage.modify(catalogModel.provider, async () => ({
+			type: "oauth",
+			access: "enterprise-token",
+			refresh: "refresh-token",
+			expires: Date.now() + 60 * 60_000,
+		}));
+		const modelRuntime = harness.session.modelRuntime;
+		modelRuntime.registerNativeProvider(provider);
+		await modelRuntime.refresh({ allowNetwork: false, providers: [catalogModel.provider] });
+		harness.session.agent.streamFunction = (model, context, options) =>
+			modelRuntime.streamSimple(model, context, options);
+
+		await harness.session.compact();
+
+		expect(requestBaseUrl).toBe(ENTERPRISE_BASE_URL);
+	});
+});

packages/coding-agent/test/suite/regressions/6904-dns-transport-retry.test.ts

@@ -0,0 +1,28 @@
+import { fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { describe, expect, it } from "vitest";
+import { createHarness } from "../harness.ts";
+
+const wrappedDnsLookupError =
+	"The pending stream has been canceled (caused by: getaddrinfo ENOTFOUND bedrock-runtime.us-east-1.amazonaws.com)";
+
+describe("issue #6904 DNS transport failure retry", () => {
+	it("retries a transient DNS lookup failure", async () => {
+		const harness = await createHarness({ settings: { retry: { enabled: true, maxRetries: 3, baseDelayMs: 1 } } });
+		try {
+			harness.setResponses([
+				fauxAssistantMessage("", { stopReason: "error", errorMessage: wrappedDnsLookupError }),
+				fauxAssistantMessage("recovered after DNS retry"),
+			]);
+
+			await harness.session.prompt("test");
+
+			expect(harness.faux.state.callCount).toBe(2);
+			expect(harness.eventsOfType("auto_retry_start").map((event) => event.errorMessage)).toEqual([
+				wrappedDnsLookupError,
+			]);
+			expect(harness.eventsOfType("auto_retry_end").map((event) => event.success)).toEqual([true]);
+		} finally {
+			harness.cleanup();
+		}
+	});
+});

packages/coding-agent/test/suite/regressions/6949-unavailable-scoped-model.test.ts

@@ -0,0 +1,162 @@
+import type { Api, Model } from "@earendil-works/pi-ai";
+import { setKeybindings } from "@earendil-works/pi-tui";
+import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+import { KeybindingsManager } from "../../../src/core/keybindings.ts";
+import { ScopedModelsSelectorComponent } from "../../../src/modes/interactive/components/scoped-models-selector.ts";
+import { InteractiveMode } from "../../../src/modes/interactive/interactive-mode.ts";
+import { initTheme, theme } from "../../../src/modes/interactive/theme/theme.ts";
+import { stripAnsi } from "../../../src/utils/ansi.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+function createInteractiveContext(options: {
+	allModels: Model<Api>[];
+	enabledModelIds: string[];
+	scopedModels?: Array<{ model: Model<Api> }>;
+}) {
+	let selector: ScopedModelsSelectorComponent | undefined;
+	const setScopedModels = vi.fn();
+	const getAvailableSnapshot = vi.fn(() => options.allModels);
+	const context = {
+		session: {
+			modelRuntime: {
+				refresh: vi.fn().mockResolvedValue({ aborted: false, errors: new Map() }),
+				getAvailableSnapshot,
+			},
+			scopedModels: options.scopedModels ?? [],
+			setScopedModels,
+		},
+		settingsManager: {
+			getEnabledModels: () => options.enabledModelIds,
+			setEnabledModels: vi.fn(),
+		},
+		showStatus: vi.fn(),
+		showSelector: (factory: (done: () => void) => { component: ScopedModelsSelectorComponent }) => {
+			selector = factory(() => {}).component;
+		},
+		updateAvailableProviderCount: vi.fn(),
+		ui: { requestRender: vi.fn() },
+	};
+	return { context, getAvailableSnapshot, getSelector: () => selector, setScopedModels };
+}
+
+async function showModelsSelector(context: object): Promise<void> {
+	const show = Reflect.get(InteractiveMode.prototype, "showModelsSelector") as (this: object) => Promise<void>;
+	await show.call(context);
+}
+
+describe("issue #6949 unavailable scoped models", () => {
+	const harnesses: Harness[] = [];
+
+	beforeAll(() => {
+		initTheme("dark");
+	});
+
+	beforeEach(() => {
+		setKeybindings(new KeybindingsManager());
+	});
+
+	afterEach(() => {
+		while (harnesses.length > 0) harnesses.pop()?.cleanup();
+	});
+
+	it("shows and removes an enabled model without a catalog entry", async () => {
+		const harness = await createHarness({ models: [{ id: "available", name: "Available" }] });
+		harnesses.push(harness);
+		const availableId = `${harness.models[0].provider}/${harness.models[0].id}`;
+		const unavailableId = `${harness.models[0].provider}/unavailable`;
+		const changes: Array<string[] | null> = [];
+		const persisted: Array<string[] | null> = [];
+		const selector = new ScopedModelsSelectorComponent(
+			{
+				allModels: [...harness.models],
+				enabledModelIds: [unavailableId, availableId],
+			},
+			{
+				onChange: (enabledIds) => {
+					changes.push(enabledIds);
+				},
+				onPersist: (enabledIds) => {
+					persisted.push(enabledIds);
+				},
+				onCancel: () => {},
+			},
+		);
+
+		const rendered = selector.render(100).join("\n");
+		expect(stripAnsi(rendered)).toContain(`${unavailableId} [unavailable]`);
+		expect(rendered).toContain(theme.strikethrough(unavailableId));
+		selector.handleInput("\r");
+		expect(changes).toEqual([[availableId]]);
+		selector.handleInput("\x13");
+		expect(persisted).toEqual([[availableId]]);
+	});
+
+	it("passes unmatched settings patterns to the selector with one combined resolution", async () => {
+		const harness = await createHarness({ models: [{ id: "available", name: "Available" }] });
+		harnesses.push(harness);
+		const unavailableIds = ["unavailable-one", "unavailable-two"].map((id) => `${harness.models[0].provider}/${id}`);
+		const { context, getAvailableSnapshot, getSelector } = createInteractiveContext({
+			allModels: [],
+			enabledModelIds: unavailableIds,
+		});
+
+		await showModelsSelector(context);
+
+		const selector = getSelector();
+		if (!selector) throw new Error("Expected scoped-model selector to open");
+		const rendered = stripAnsi(selector.render(100).join("\n"));
+		for (const unavailableId of unavailableIds) {
+			expect(rendered).toContain(`${unavailableId} [unavailable]`);
+		}
+		expect(getAvailableSnapshot).toHaveBeenCalled();
+	});
+
+	it("opens when only a session-scoped model is unavailable", async () => {
+		const harness = await createHarness({ models: [{ id: "unavailable", name: "Unavailable" }] });
+		harnesses.push(harness);
+		const model = harness.models[0];
+		const fullId = `${model.provider}/${model.id}`;
+		const { context, getSelector } = createInteractiveContext({
+			allModels: [],
+			enabledModelIds: [],
+			scopedModels: [{ model }],
+		});
+
+		await showModelsSelector(context);
+
+		const selector = getSelector();
+		if (!selector) throw new Error("Expected scoped-model selector to open");
+		expect(stripAnsi(selector.render(100).join("\n"))).toContain(`${fullId} [unavailable]`);
+	});
+
+	it("does not clear a partial scope when an enabled model is unavailable", async () => {
+		const harness = await createHarness({
+			models: [
+				{ id: "one", name: "One" },
+				{ id: "two", name: "Two" },
+				{ id: "three", name: "Three" },
+			],
+		});
+		harnesses.push(harness);
+		const [one, two] = harness.models;
+		const enabledIds = [one, two].map((model) => `${model.provider}/${model.id}`);
+		const unavailableId = `${one.provider}/unavailable`;
+		const { context, getSelector, setScopedModels } = createInteractiveContext({
+			allModels: [...harness.models],
+			enabledModelIds: [...enabledIds, unavailableId],
+			scopedModels: [{ model: one }, { model: two }],
+		});
+
+		await showModelsSelector(context);
+		const selector = getSelector();
+		if (!selector) throw new Error("Expected scoped-model selector to open");
+		selector.handleInput("\x1b[1;3B");
+
+		await vi.waitFor(() => {
+			expect(setScopedModels).toHaveBeenLastCalledWith([
+				{ model: two, thinkingLevel: undefined },
+				{ model: one, thinkingLevel: undefined },
+			]);
+		});
+	});
+});

packages/coding-agent/test/suite/regressions/6999-models-json-hot-reload.test.ts

@@ -0,0 +1,82 @@
+import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { setKeybindings, type TUI } from "@earendil-works/pi-tui";
+import { afterEach, beforeAll, beforeEach, describe, expect, it } from "vitest";
+import { AuthStorage } from "../../../src/core/auth-storage.ts";
+import { KeybindingsManager } from "../../../src/core/keybindings.ts";
+import { ModelSelectorComponent } from "../../../src/modes/interactive/components/model-selector.ts";
+import { initTheme } from "../../../src/modes/interactive/theme/theme.ts";
+import { stripAnsi } from "../../../src/utils/ansi.ts";
+import { createModelRegistry, getModelRuntime } from "../../model-runtime-test-utils.ts";
+
+function observeRefreshRender(): { tui: TUI; renderedAfterRefresh: Promise<void> } {
+	let renderCount = 0;
+	let resolveRefreshRender = () => {};
+	const renderedAfterRefresh = new Promise<void>((resolve) => {
+		resolveRefreshRender = resolve;
+	});
+	return {
+		tui: {
+			requestRender: () => {
+				renderCount++;
+				if (renderCount === 2) resolveRefreshRender();
+			},
+		} as unknown as TUI,
+		renderedAfterRefresh,
+	};
+}
+
+function modelsJson(provider: string, model: string): Record<string, unknown> {
+	return {
+		providers: {
+			[provider]: {
+				baseUrl: "https://example.test/v1",
+				api: "openai-completions",
+				apiKey: "test-key",
+				models: [{ id: model }],
+			},
+		},
+	};
+}
+
+describe("issue #6999 models.json hot reload", () => {
+	let tempDir: string | undefined;
+
+	beforeAll(() => {
+		initTheme("dark");
+	});
+
+	beforeEach(() => {
+		setKeybindings(new KeybindingsManager());
+	});
+
+	afterEach(() => {
+		if (tempDir) rmSync(tempDir, { recursive: true, force: true });
+		tempDir = undefined;
+	});
+
+	it("reloads models.json when opening /model", async () => {
+		tempDir = mkdtempSync(join(tmpdir(), "pi-models-json-hot-reload-"));
+		const modelsPath = join(tempDir, "models.json");
+		writeFileSync(modelsPath, JSON.stringify(modelsJson("old-provider", "old-model")));
+		const modelRuntime = getModelRuntime(await createModelRegistry(AuthStorage.inMemory(), modelsPath));
+		expect(modelRuntime.getModel("old-provider", "old-model")).toBeDefined();
+
+		writeFileSync(modelsPath, JSON.stringify(modelsJson("new-provider", "new-model")));
+		const { tui, renderedAfterRefresh } = observeRefreshRender();
+		const selector = new ModelSelectorComponent(
+			tui,
+			undefined,
+			modelRuntime,
+			[],
+			() => {},
+			() => {},
+		);
+
+		await renderedAfterRefresh;
+		const rendered = stripAnsi(selector.render(120).join("\n"));
+		expect(rendered).toContain("new-model [new-provider]");
+		expect(rendered).not.toContain("old-model [old-provider]");
+	});
+});

packages/coding-agent/test/suite/regressions/7027-credential-refresh-hang.test.ts

@@ -0,0 +1,125 @@
+import type { Api, Model, Provider } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { AuthStorage } from "../../../src/core/auth-storage.ts";
+import { ModelRuntime } from "../../../src/core/model-runtime.ts";
+import { InteractiveMode } from "../../../src/modes/interactive/interactive-mode.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+const dynamicModel: Model<"openai-completions"> = {
+	id: "dynamic",
+	name: "Dynamic",
+	api: "openai-completions",
+	provider: "stalled-login",
+	baseUrl: "https://example.test/v1",
+	reasoning: false,
+	input: ["text"],
+	cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+	contextWindow: 1000,
+	maxTokens: 100,
+};
+
+describe("issues #7027 and #7113 credential refresh hang", () => {
+	let harness: Harness | undefined;
+
+	afterEach(() => {
+		vi.useRealTimers();
+		harness?.cleanup();
+		harness = undefined;
+		vi.restoreAllMocks();
+	});
+
+	it("does not hold login behind an older stalled network catalog refresh", async () => {
+		let markNetworkStarted: (() => void) | undefined;
+		const networkStarted = new Promise<void>((resolve) => {
+			markNetworkStarted = resolve;
+		});
+		const provider: Provider<"openai-completions"> = {
+			id: "stalled-login",
+			name: "Stalled Login",
+			auth: {
+				apiKey: {
+					name: "API key",
+					login: async () => ({ type: "api_key", key: "secret" }),
+					check: async ({ credential }) =>
+						credential?.key ? { type: "api_key", source: "stored key" } : undefined,
+					resolve: async ({ credential }) => ({
+						auth: { apiKey: credential?.key ?? "ambient-key" },
+						source: credential?.key ? "stored key" : "ambient key",
+					}),
+				},
+			},
+			getModels: () => [dynamicModel],
+			refreshModels: async ({ allowNetwork }) => {
+				if (!allowNetwork) return;
+				markNetworkStarted?.();
+				await new Promise<void>(() => {});
+			},
+			stream: () => {
+				throw new Error("unused");
+			},
+			streamSimple: () => {
+				throw new Error("unused");
+			},
+		};
+		const credentials = AuthStorage.inMemory();
+		const runtime = await ModelRuntime.create({ credentials, modelsPath: null, allowModelNetwork: false });
+		runtime.registerNativeProvider(provider);
+		await runtime.refresh({ allowNetwork: false, providers: [provider.id] });
+
+		const stalledRefresh = runtime.refresh({ allowNetwork: true, providers: [provider.id] });
+		await networkStarted;
+		await expect(
+			runtime.login(provider.id, "api_key", { prompt: async () => "unused", notify: () => {} }),
+		).resolves.toEqual({ type: "api_key", key: "secret" });
+
+		expect(runtime.getAvailableSnapshot().map((model) => model.id)).toContain(dynamicModel.id);
+		expect(await credentials.read(provider.id)).toEqual({ type: "api_key", key: "secret" });
+		await expect(stalledRefresh).resolves.toMatchObject({ aborted: false });
+	});
+
+	it("completes interactive login before its bounded background refresh", async () => {
+		harness = await createHarness();
+		vi.useFakeTimers();
+		const runtime = harness.session.modelRuntime;
+		vi.spyOn(runtime, "refresh").mockImplementation(
+			(options) =>
+				new Promise((resolve) => {
+					options?.signal?.addEventListener("abort", () => resolve({ aborted: true, errors: new Map() }), {
+						once: true,
+					});
+				}),
+		);
+		const showWarning = vi.fn();
+		const context = {
+			session: harness.session,
+			updateAvailableProviderCount: vi.fn(),
+			footer: { invalidate: vi.fn() },
+			updateEditorBorderColor: vi.fn(),
+			showStatus: vi.fn(),
+			showError: vi.fn(),
+			showWarning,
+			maybeWarnAboutAnthropicSubscriptionAuth: vi.fn(),
+			checkDaxnutsEasterEgg: vi.fn(),
+			ui: { requestRender: vi.fn() },
+		};
+		const complete = Reflect.get(InteractiveMode.prototype, "completeProviderAuthentication") as (
+			this: object,
+			providerId: string,
+			providerName: string,
+			authType: "oauth" | "api_key",
+			previousModel: Model<Api>,
+		) => Promise<void>;
+
+		await complete.call(context, dynamicModel.provider, "Stalled Login", "api_key", harness.getModel());
+		expect(runtime.refresh).toHaveBeenCalledWith({
+			providers: [dynamicModel.provider],
+			signal: expect.any(AbortSignal),
+		});
+		expect(showWarning).not.toHaveBeenCalled();
+
+		await vi.advanceTimersByTimeAsync(15_000);
+		expect(showWarning).toHaveBeenCalledWith(
+			"Saved API key for Stalled Login, but its model catalog refresh timed out; using cached models.",
+		);
+	});
+});

packages/coding-agent/test/suite/regressions/7048-compaction-truncated-summary.test.ts

@@ -0,0 +1,48 @@
+import { type AssistantMessage, fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, type Harness } from "../harness.ts";
+
+function seedCompactableSession(harness: Harness): void {
+	harness.settingsManager.applyOverrides({ compaction: { keepRecentTokens: 1 } });
+	const now = Date.now();
+	harness.sessionManager.appendMessage({
+		role: "user",
+		content: [{ type: "text", text: "message to compact" }],
+		timestamp: now - 1000,
+	});
+	const model = harness.getModel();
+	const assistant: AssistantMessage = {
+		...fauxAssistantMessage("assistant response to compact", { timestamp: now - 500 }),
+		api: model.api,
+		provider: model.provider,
+		model: model.id,
+		usage: {
+			input: 100,
+			output: 0,
+			cacheRead: 0,
+			cacheWrite: 0,
+			totalTokens: 100,
+			cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+		},
+	};
+	harness.sessionManager.appendMessage(assistant);
+	harness.session.agent.state.messages = harness.sessionManager.buildSessionContext().messages;
+}
+
+describe("#7048 truncated compaction summaries", () => {
+	let harness: Harness | undefined;
+
+	afterEach(() => {
+		harness?.cleanup();
+		harness = undefined;
+	});
+
+	it("does not persist a length-limited summary", async () => {
+		harness = await createHarness();
+		seedCompactableSession(harness);
+		harness.setResponses([fauxAssistantMessage("partial summar", { stopReason: "length" })]);
+
+		await expect(harness.session.compact()).rejects.toThrow("generation hit the token cap");
+		expect(harness.sessionManager.getEntries().filter((entry) => entry.type === "compaction")).toHaveLength(0);
+	});
+});

packages/coding-agent/test/suite/regressions/7150-rpc-prompt-during-compaction.test.ts

@@ -0,0 +1,91 @@
+import { fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, getMessageText, getUserTexts, type Harness } from "../harness.ts";
+
+describe("issue #7150: RPC prompt during manual compaction", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("rejects an RPC prompt while manual compaction is in progress", async () => {
+		let markCompactionStarted = () => {};
+		const compactionStarted = new Promise<void>((resolve) => {
+			markCompactionStarted = resolve;
+		});
+		let releaseCompaction = () => {};
+		const compactionReleased = new Promise<void>((resolve) => {
+			releaseCompaction = resolve;
+		});
+
+		const harness = await createHarness({
+			settings: { compaction: { keepRecentTokens: 1 } },
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_compact", async (event) => {
+						markCompactionStarted();
+						await compactionReleased;
+						return {
+							compaction: {
+								summary: "manual compacted",
+								firstKeptEntryId: event.preparation.firstKeptEntryId,
+								tokensBefore: event.preparation.tokensBefore,
+								details: {},
+							},
+						};
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		const timestamp = Date.now();
+		harness.sessionManager.appendMessage({
+			role: "user",
+			content: [{ type: "text", text: "old user message" }],
+			timestamp: timestamp - 1000,
+		});
+		harness.sessionManager.appendMessage(
+			fauxAssistantMessage("old assistant response", { timestamp: timestamp - 500 }),
+		);
+		harness.session.agent.state.messages = harness.sessionManager.buildSessionContext().messages;
+		harness.setResponses([fauxAssistantMessage("probe response")]);
+
+		const compactPromise = harness.session.compact();
+		await compactionStarted;
+
+		let preflightResult: boolean | undefined;
+		let promptError: unknown;
+		try {
+			await harness.session.prompt("PROBE-7150", {
+				source: "rpc",
+				preflightResult: (success) => {
+					preflightResult = success;
+				},
+			});
+		} catch (error) {
+			promptError = error;
+		} finally {
+			releaseCompaction();
+			await compactPromise;
+		}
+
+		const persistedUserTexts = harness.sessionManager
+			.getEntries()
+			.flatMap((entry) =>
+				entry.type === "message" && entry.message.role === "user" ? [getMessageText(entry.message)] : [],
+			);
+
+		expect(preflightResult).toBe(false);
+		expect(promptError).toEqual(
+			expect.objectContaining({ message: expect.stringContaining("compaction is in progress") }),
+		);
+		expect(getUserTexts(harness)).not.toContain("PROBE-7150");
+		expect(persistedUserTexts).not.toContain("PROBE-7150");
+		expect(harness.eventsOfType("agent_start")).toHaveLength(0);
+		expect(harness.eventsOfType("agent_settled")).toHaveLength(0);
+	});
+});

packages/coding-agent/test/suite/regressions/7153-scoped-models-refresh.test.ts

@@ -0,0 +1,107 @@
+import type { Api, Model, ModelsRefreshResult } from "@earendil-works/pi-ai";
+import { setKeybindings, type TUI } from "@earendil-works/pi-tui";
+import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+import { KeybindingsManager } from "../../../src/core/keybindings.ts";
+import type { ScopedModelsSelectorComponent } from "../../../src/modes/interactive/components/scoped-models-selector.ts";
+import { InteractiveMode } from "../../../src/modes/interactive/interactive-mode.ts";
+import { initTheme } from "../../../src/modes/interactive/theme/theme.ts";
+import { stripAnsi } from "../../../src/utils/ansi.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+const showModelsSelector = Reflect.get(InteractiveMode.prototype, "showModelsSelector") as (this: object) => void;
+
+function openSelector(harness: Harness, initialModels: readonly Model<Api>[]) {
+	let snapshot = initialModels;
+	let finishRefresh: ((result: ModelsRefreshResult) => void) | undefined;
+	let refreshSignal: AbortSignal | undefined;
+	let selector: ScopedModelsSelectorComponent | undefined;
+	let dispose: (() => void) | undefined;
+	const done = vi.fn();
+	vi.spyOn(harness.session.modelRuntime, "getAvailableSnapshot").mockImplementation(() => snapshot);
+	vi.spyOn(harness.session.modelRuntime, "refresh").mockImplementation(
+		(options) =>
+			new Promise((resolve) => {
+				refreshSignal = options?.signal;
+				finishRefresh = resolve;
+			}),
+	);
+	const context = {
+		session: harness.session,
+		settingsManager: harness.settingsManager,
+		showSelector: (
+			factory: (close: () => void) => {
+				component: ScopedModelsSelectorComponent;
+				dispose?: () => void;
+			},
+		) => {
+			const close = () => {
+				dispose?.();
+				done();
+			};
+			const created = factory(close);
+			selector = created.component;
+			dispose = created.dispose;
+		},
+		updateAvailableProviderCount: vi.fn(),
+		ui: { requestRender: vi.fn() } as unknown as TUI,
+	};
+
+	showModelsSelector.call(context);
+	if (!selector) throw new Error("Expected scoped-model selector to open");
+	return {
+		done,
+		get refreshSignal() {
+			return refreshSignal;
+		},
+		selector,
+		complete(models: readonly Model<Api>[], result: ModelsRefreshResult) {
+			snapshot = models;
+			if (!finishRefresh) throw new Error("Expected model refresh to start");
+			finishRefresh(result);
+		},
+	};
+}
+
+describe("issue #7153 scoped models refresh", () => {
+	let harness: Harness | undefined;
+
+	beforeAll(() => initTheme("dark"));
+	beforeEach(() => setKeybindings(new KeybindingsManager()));
+	afterEach(() => {
+		harness?.cleanup();
+		harness = undefined;
+		vi.restoreAllMocks();
+	});
+
+	it("renders cached models immediately and updates after background refresh", async () => {
+		harness = await createHarness({
+			models: [
+				{ id: "cached", name: "Cached" },
+				{ id: "refreshed", name: "Refreshed" },
+			],
+		});
+		const refresh = openSelector(harness, [harness.models[0]]);
+
+		const initial = stripAnsi(refresh.selector.render(100).join("\n"));
+		expect(initial).toContain("cached");
+		expect(initial).toContain("Refreshing model catalogs…");
+		expect(initial).not.toContain("refreshed");
+
+		refresh.complete(harness.models, { aborted: false, errors: new Map() });
+		await vi.waitFor(() => {
+			const rendered = stripAnsi(refresh.selector.render(100).join("\n"));
+			expect(rendered).toContain("refreshed");
+			expect(rendered).toContain("Model catalogs refreshed.");
+		});
+	});
+
+	it("cancels the background refresh when the selector closes", async () => {
+		harness = await createHarness({ models: [{ id: "cached", name: "Cached" }] });
+		const refresh = openSelector(harness, harness.models);
+
+		expect(refresh.refreshSignal).toBeDefined();
+		refresh.selector.handleInput("\x1b");
+		await vi.waitFor(() => expect(refresh.refreshSignal?.aborted).toBe(true));
+		expect(refresh.done).toHaveBeenCalledOnce();
+	});
+});

packages/coding-agent/test/suite/regressions/7187-malformed-package-manifest.test.ts

@@ -0,0 +1,47 @@
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { describe, expect, it } from "vitest";
+import { DefaultPackageManager } from "../../../src/core/package-manager.ts";
+import { SettingsManager } from "../../../src/core/settings-manager.ts";
+import { createHarness } from "../harness.ts";
+
+describe("issue #7187 malformed package manifest", () => {
+	it("ignores invalid resource fields without dropping valid fields", async () => {
+		const harness = await createHarness();
+		const tempDir = mkdtempSync(join(tmpdir(), "pi-7187-"));
+		const agentDir = join(tempDir, "agent");
+		try {
+			const packageDir = join(agentDir, "npm", "node_modules", "bad-package");
+			const skillPath = join(packageDir, "skills", "bad", "SKILL.md");
+			const promptPath = join(packageDir, "prompts", "valid.md");
+			mkdirSync(join(packageDir, "skills", "bad"), { recursive: true });
+			mkdirSync(join(packageDir, "prompts"), { recursive: true });
+			writeFileSync(skillPath, "---\nname: bad\ndescription: Must not load\n---\n");
+			writeFileSync(promptPath, "Valid prompt\n");
+			writeFileSync(
+				join(packageDir, "package.json"),
+				JSON.stringify({
+					name: "bad-package",
+					version: "1.0.0",
+					pi: {
+						skills: "./skills",
+						prompts: ["./prompts"],
+					},
+				}),
+			);
+			const packageManager = new DefaultPackageManager({
+				cwd: tempDir,
+				agentDir,
+				settingsManager: SettingsManager.inMemory({ packages: ["npm:bad-package"] }),
+			});
+
+			const resources = await packageManager.resolve();
+			expect(resources.skills.map((skill) => skill.path)).not.toContain(skillPath);
+			expect(resources.prompts.map((prompt) => prompt.path)).toContain(promptPath);
+		} finally {
+			rmSync(tempDir, { recursive: true, force: true });
+			harness.cleanup();
+		}
+	});
+});

packages/coding-agent/test/suite/regressions/7193-event-bus-lifecycle.test.ts

@@ -0,0 +1,70 @@
+import { afterEach, describe, expect, it } from "vitest";
+import { createEventBus } from "../../../src/core/event-bus.ts";
+import { createExtensionRuntime, loadExtensionFromFactory } from "../../../src/core/extensions/loader.ts";
+import type { ExtensionAPI, ExtensionFactory, ResourceLoader } from "../../../src/index.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+describe("issue #7193 extension event-bus lifecycle", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("removes extension-owned event-bus listeners on reload and dispose", async () => {
+		const eventBus = createEventBus();
+		let extensionCalls = 0;
+		let hostCalls = 0;
+		let firstApi: ExtensionAPI | undefined;
+		const factory: ExtensionFactory = (pi) => {
+			firstApi ??= pi;
+			pi.events.on("reload:test", () => extensionCalls++);
+		};
+		eventBus.on("reload:test", () => hostCalls++);
+
+		const loadExtensions = async () => {
+			const runtime = createExtensionRuntime();
+			const extension = await loadExtensionFromFactory(factory, process.cwd(), eventBus, runtime);
+			return { extensions: [extension], errors: [], runtime };
+		};
+		let extensionsResult = await loadExtensions();
+		const resourceLoader: ResourceLoader = {
+			getExtensions: () => extensionsResult,
+			getSkills: () => ({ skills: [], diagnostics: [] }),
+			getPrompts: () => ({ prompts: [], diagnostics: [] }),
+			getThemes: () => ({ themes: [], diagnostics: [] }),
+			getAgentsFiles: () => ({ agentsFiles: [] }),
+			getSystemPrompt: () => undefined,
+			getSystemPromptSource: () => undefined,
+			getAppendSystemPrompt: () => [],
+			getAppendSystemPromptSources: () => [],
+			extendResources: () => {},
+			reload: async () => {
+				extensionsResult = await loadExtensions();
+			},
+		};
+		const harness = await createHarness({ resourceLoader });
+		harnesses.push(harness);
+		await harness.session.bindExtensions({ shutdownHandler: () => {} });
+
+		const emit = async () => {
+			const extensionBefore = extensionCalls;
+			const hostBefore = hostCalls;
+			eventBus.emit("reload:test", undefined);
+			await new Promise((resolve) => setImmediate(resolve));
+			return { extension: extensionCalls - extensionBefore, host: hostCalls - hostBefore };
+		};
+
+		expect(await emit()).toEqual({ extension: 1, host: 1 });
+		await harness.session.reload();
+		expect(() => firstApi?.getCommands()).toThrow("stale after session replacement or reload");
+		expect(await emit()).toEqual({ extension: 1, host: 1 });
+		await harness.session.reload();
+		expect(await emit()).toEqual({ extension: 1, host: 1 });
+
+		harness.session.dispose();
+		expect(await emit()).toEqual({ extension: 0, host: 1 });
+	});
+});

packages/coding-agent/test/suite/regressions/7209-model-selector-filter-resets-selection.test.ts

@@ -0,0 +1,126 @@
+import { setKeybindings, type TUI } from "@earendil-works/pi-tui";
+import { afterAll, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+import { KeybindingsManager } from "../../../src/core/keybindings.ts";
+import { ModelSelectorComponent } from "../../../src/modes/interactive/components/model-selector.ts";
+import { initTheme } from "../../../src/modes/interactive/theme/theme.ts";
+import { stripAnsi } from "../../../src/utils/ansi.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+function createFakeTui(): TUI {
+	return { requestRender: () => {} } as unknown as TUI;
+}
+
+/** Return the model id of the highlighted (→) row in the rendered selector. */
+function selectedModelId(rendered: string): string | undefined {
+	const line = rendered.split("\n").find((l) => l.startsWith("→ "));
+	if (!line) return undefined;
+	const rest = line.replace(/^→\s*/, "");
+	const id = rest.split(" [")[0]?.replace(/^✓\s*/, "");
+	return id?.trim() || undefined;
+}
+
+describe("model selector filter resets selection to top", () => {
+	const harnesses: Harness[] = [];
+
+	beforeAll(() => {
+		initTheme("dark");
+	});
+
+	beforeEach(() => {
+		setKeybindings(new KeybindingsManager());
+	});
+
+	afterAll(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("moves selection to the first row in the All tab when typing a query", async () => {
+		const harness = await createHarness({
+			models: [
+				{ id: "alpha-1", name: "Alpha One", reasoning: true },
+				{ id: "alpha-2", name: "Alpha Two", reasoning: true },
+				{ id: "alpha-3", name: "Alpha Three", reasoning: true },
+				{ id: "beta-1", name: "Beta One", reasoning: true },
+			],
+		});
+		harnesses.push(harness);
+
+		const current = harness.getModel("alpha-1")!;
+		const selector = new ModelSelectorComponent(
+			createFakeTui(),
+			current,
+			harness.session.modelRuntime,
+			[],
+			() => {},
+			() => {},
+		);
+
+		await vi.waitFor(() => {
+			const rendered = stripAnsi(selector.render(120).join("\n"));
+			expect(rendered).toContain("Model catalogs refreshed.");
+		});
+
+		// Current model (alpha-1) is sorted first, so selection starts on row 0.
+		expect(selectedModelId(stripAnsi(selector.render(120).join("\n")))).toBe("alpha-1");
+
+		// Move selection down two rows to alpha-3.
+		selector.handleInput("\x1b[B");
+		selector.handleInput("\x1b[B");
+		expect(selectedModelId(stripAnsi(selector.render(120).join("\n")))).toBe("alpha-3");
+
+		// Type a query that matches the three alpha models. The selection must
+		// move back to the top row (alpha-1), not stay clamped at index 2.
+		for (const char of "alpha") {
+			selector.handleInput(char);
+		}
+
+		const rendered = stripAnsi(selector.render(120).join("\n"));
+		expect(selectedModelId(rendered)).toBe("alpha-1");
+		// Sanity: the filter actually narrowed the list.
+		expect(rendered).not.toContain("beta-1");
+	});
+
+	it("moves selection to the first row in the Scoped tab when typing a query", async () => {
+		const harness = await createHarness({
+			models: [
+				{ id: "alpha-1", name: "Alpha One", reasoning: true },
+				{ id: "alpha-2", name: "Alpha Two", reasoning: true },
+				{ id: "alpha-3", name: "Alpha Three", reasoning: true },
+			],
+		});
+		harnesses.push(harness);
+
+		const alpha1 = harness.getModel("alpha-1")!;
+		const alpha2 = harness.getModel("alpha-2")!;
+		const alpha3 = harness.getModel("alpha-3")!;
+
+		// Scoped list is intentionally not in current-model-first order; the
+		// current model (alpha-1) sits at index 2.
+		const selector = new ModelSelectorComponent(
+			createFakeTui(),
+			alpha1,
+			harness.session.modelRuntime,
+			[{ model: alpha2 }, { model: alpha3 }, { model: alpha1 }],
+			() => {},
+			() => {},
+		);
+
+		await vi.waitFor(() => {
+			const rendered = stripAnsi(selector.render(120).join("\n"));
+			expect(rendered).toContain("Model catalogs refreshed.");
+		});
+
+		// Selection starts on the current model (alpha-1), which is row 2 here.
+		expect(selectedModelId(stripAnsi(selector.render(120).join("\n")))).toBe("alpha-1");
+
+		// Type a query matching all three scoped models. Selection must move to
+		// the top row (alpha-2), not stay clamped at index 2 (alpha-1).
+		for (const char of "alpha") {
+			selector.handleInput(char);
+		}
+
+		expect(selectedModelId(stripAnsi(selector.render(120).join("\n")))).toBe("alpha-2");
+	});
+});

packages/coding-agent/test/suite/regressions/7253-manual-compact-during-response.test.ts

@@ -0,0 +1,83 @@
+import type { AgentTool } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, type Harness } from "../harness.ts";
+
+function createNoopTool(): AgentTool {
+	return {
+		name: "noop",
+		label: "No-op",
+		description: "Return immediately",
+		parameters: Type.Object({}),
+		execute: async () => ({ content: [{ type: "text", text: "done" }], details: {} }),
+	};
+}
+
+describe("issue #7253: manual compaction during an active response", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("persists the aborted response before running the requested manual compaction", async () => {
+		let markSecondResponseStarted = () => {};
+		const secondResponseStarted = new Promise<void>((resolve) => {
+			markSecondResponseStarted = resolve;
+		});
+		let releaseSecondResponse = () => {};
+		const secondResponseReleased = new Promise<void>((resolve) => {
+			releaseSecondResponse = resolve;
+		});
+
+		const harness = await createHarness({
+			models: [{ id: "faux-1", contextWindow: 1000, maxTokens: 1000 }],
+			settings: { compaction: { enabled: true, reserveTokens: 200, keepRecentTokens: 2 } },
+			tools: [createNoopTool()],
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_compact", async (event) => ({
+						compaction: {
+							summary: `${event.reason} summary`,
+							firstKeptEntryId: event.preparation.firstKeptEntryId,
+							tokensBefore: event.preparation.tokensBefore,
+							details: {},
+						},
+					}));
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage(fauxToolCall("noop", {}), { stopReason: "toolUse" }),
+			async () => {
+				markSecondResponseStarted();
+				await secondResponseReleased;
+				return fauxAssistantMessage(`second response:${"x".repeat(4000)}`);
+			},
+		]);
+
+		const promptPromise = harness.session.prompt("Run the tool, then continue responding.");
+		await secondResponseStarted;
+
+		const compactPromise = harness.session.compact();
+		const compactExpectation = expect(compactPromise).resolves.toMatchObject({ summary: "manual summary" });
+		releaseSecondResponse();
+		await Promise.all([promptPromise, compactExpectation]);
+
+		expect(harness.eventsOfType("compaction_start").map((event) => event.reason)).toEqual(["manual"]);
+		expect(harness.eventsOfType("compaction_end").map((event) => event.reason)).toEqual(["manual"]);
+		const entries = harness.sessionManager.getEntries();
+		const abortedResponseIndex = entries.findIndex(
+			(entry) =>
+				entry.type === "message" && entry.message.role === "assistant" && entry.message.stopReason === "aborted",
+		);
+		const compactionIndex = entries.findIndex((entry) => entry.type === "compaction");
+		expect(abortedResponseIndex).toBeGreaterThan(-1);
+		expect(compactionIndex).toBeGreaterThan(abortedResponseIndex);
+		expect(entries.filter((entry) => entry.type === "compaction")).toHaveLength(1);
+	});
+});

packages/coding-agent/test/suite/regressions/7269-cli-end-of-options.test.ts

@@ -0,0 +1,39 @@
+import { fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import { parseArgs } from "../../../src/cli/args.ts";
+import { createHarness, getUserTexts, type Harness } from "../harness.ts";
+
+describe("issue #7269 CLI end-of-options delimiter", () => {
+	let harness: Harness | undefined;
+
+	afterEach(() => {
+		harness?.cleanup();
+		harness = undefined;
+	});
+
+	it.each(["- summarize the following points for me", "--answer my question briefly"])(
+		"passes %j as a prompt after --",
+		async (prompt) => {
+			const parsed = parseArgs(["-ne", "--no-session", "-p", "--", prompt]);
+			expect(parsed.messages).toEqual([prompt]);
+			expect(parsed.unknownFlags.size).toBe(0);
+			expect(parsed.diagnostics).toEqual([]);
+
+			harness = await createHarness();
+			harness.setResponses([fauxAssistantMessage("ok")]);
+			await harness.session.prompt(parsed.messages[0]);
+			expect(getUserTexts(harness)).toEqual([prompt]);
+		},
+	);
+
+	it("stops parsing options while retaining @file handling", () => {
+		const parsed = parseArgs(["--unknown-flag", "value", "--", "--provider", "openai", "-c", "@prompt.md"]);
+
+		expect(parsed.unknownFlags.get("unknown-flag")).toBe("value");
+		expect(parsed.provider).toBeUndefined();
+		expect(parsed.continue).toBeUndefined();
+		expect(parsed.messages).toEqual(["--provider", "openai", "-c"]);
+		expect(parsed.fileArgs).toEqual(["prompt.md"]);
+		expect(parsed.diagnostics).toEqual([]);
+	});
+});

packages/coding-agent/test/suite/regressions/7290-json-stream-linear.test.ts

@@ -0,0 +1,44 @@
+import { fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import { toJsonEvent } from "../../../src/modes/json-event.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+describe("regression #7290: JSON event streams stay linear", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	async function measureUpdateBytes(text: string): Promise<number> {
+		const harness = await createHarness();
+		harnesses.push(harness);
+		harness.setResponses([fauxAssistantMessage(text)]);
+
+		await harness.session.prompt("respond");
+
+		const sessionUpdates = harness.eventsOfType("message_update");
+		for (const update of sessionUpdates) {
+			expect(update).toHaveProperty("message");
+			expect(update.assistantMessageEvent).toHaveProperty("partial");
+		}
+
+		const updates = sessionUpdates.map((event) => toJsonEvent(event));
+		expect(updates.length).toBeGreaterThan(0);
+		for (const update of updates) {
+			expect(update).not.toHaveProperty("message");
+			expect(update.assistantMessageEvent).not.toHaveProperty("partial");
+		}
+		return updates.reduce((bytes, event) => bytes + Buffer.byteLength(JSON.stringify(event)), 0);
+	}
+
+	it("emits delta-only message updates whose size scales linearly", async () => {
+		const smallBytes = await measureUpdateBytes("x".repeat(2_000));
+		const largeBytes = await measureUpdateBytes("x".repeat(4_000));
+
+		expect(largeBytes).toBeGreaterThan(smallBytes);
+		expect(largeBytes / smallBytes).toBeLessThan(2.2);
+	});
+});

packages/coding-agent/test/suite/regressions/7301-stalled-availability-refresh.test.ts

@@ -0,0 +1,133 @@
+import type { Models } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { createHarness, type Harness } from "../harness.ts";
+
+interface Deferred {
+	promise: Promise<void>;
+	resolve(): void;
+	reject(error: Error): void;
+}
+
+interface StalledCredentialList {
+	started: Promise<void>;
+	release(): void;
+	fail(error: Error): void;
+	getCallCount(): number;
+}
+
+function createDeferred(): Deferred {
+	let resolvePromise = () => {};
+	let rejectPromise = (_error: Error) => {};
+	const promise = new Promise<void>((resolve, reject) => {
+		resolvePromise = resolve;
+		rejectPromise = reject;
+	});
+	return { promise, resolve: resolvePromise, reject: rejectPromise };
+}
+
+function stallNextCredentialList(harness: Harness): StalledCredentialList {
+	const originalList = harness.authStorage.list.bind(harness.authStorage);
+	const started = createDeferred();
+	const gate = createDeferred();
+	let shouldStall = true;
+	let callCount = 0;
+
+	harness.authStorage.list = async () => {
+		const entries = await originalList();
+		callCount++;
+		if (!shouldStall) return entries;
+		shouldStall = false;
+		started.resolve();
+		await gate.promise;
+		return entries;
+	};
+
+	return {
+		started: started.promise,
+		release: gate.resolve,
+		fail: gate.reject,
+		getCallCount: () => callCount,
+	};
+}
+
+async function waitForRecoveryRefresh(stalledList: StalledCredentialList, harness: Harness): Promise<void> {
+	const refresh = harness.session.modelRuntime.refresh({ allowNetwork: false });
+	await vi.waitFor(() => expect(stalledList.getCallCount()).toBe(2));
+	await refresh;
+}
+
+describe("issue #7301 stalled availability refresh", () => {
+	let harness: Harness | undefined;
+	let stalledList: StalledCredentialList | undefined;
+
+	afterEach(() => {
+		stalledList?.release();
+		stalledList = undefined;
+		harness?.cleanup();
+		harness = undefined;
+	});
+
+	it("recovers without letting the stalled refresh overwrite the newer snapshot", async () => {
+		harness = await createHarness({ withConfiguredAuth: false });
+		const runtime = harness.session.modelRuntime;
+		await harness.authStorage.modify("stale-provider", async () => ({ type: "api_key", key: "stale-key" }));
+		await runtime.refresh({ allowNetwork: false });
+		expect(runtime.getProviderAuthStatus("stale-provider")).toEqual({ configured: true, source: "stored" });
+
+		stalledList = stallNextCredentialList(harness);
+		const staleRefresh = runtime.getAvailable();
+		await stalledList.started;
+
+		await harness.authStorage.delete("stale-provider");
+		await harness.authStorage.modify("current-provider", async () => ({ type: "api_key", key: "current-key" }));
+		await waitForRecoveryRefresh(stalledList, harness);
+		expect(runtime.getProviderAuthStatus("stale-provider")).toEqual({ configured: false });
+		expect(runtime.getProviderAuthStatus("current-provider")).toEqual({ configured: true, source: "stored" });
+
+		stalledList.release();
+		await staleRefresh;
+		expect(runtime.getProviderAuthStatus("stale-provider")).toEqual({ configured: false });
+		expect(runtime.getProviderAuthStatus("current-provider")).toEqual({ configured: true, source: "stored" });
+	});
+
+	it("does not let a stale failure overwrite newer availability error state", async () => {
+		harness = await createHarness({ withConfiguredAuth: false });
+		const runtime = harness.session.modelRuntime;
+		stalledList = stallNextCredentialList(harness);
+		const staleRefresh = runtime.getAvailable();
+		await stalledList.started;
+
+		await waitForRecoveryRefresh(stalledList, harness);
+		expect(runtime.getError()).toBeUndefined();
+
+		stalledList.fail(new Error("stale credential list failure"));
+		await expect(staleRefresh).rejects.toThrow("stale credential list failure");
+		expect(runtime.getError()).toBeUndefined();
+	});
+
+	it("does not let a stale provider-scoped failure overwrite a newer availability pass", async () => {
+		harness = await createHarness();
+		const runtime = harness.session.modelRuntime;
+		const models = Reflect.get(runtime, "models") as Models;
+		const originalGetAvailable = models.getAvailable.bind(models);
+		const started = createDeferred();
+		const gate = createDeferred();
+		let stall = true;
+		models.getAvailable = async (providerId, options) => {
+			if (!providerId || !stall) return originalGetAvailable(providerId, options);
+			stall = false;
+			started.resolve();
+			await gate.promise;
+			throw new Error("stale provider availability failure");
+		};
+
+		const staleRefresh = runtime.getAvailable(harness.getModel().provider);
+		await started.promise;
+		await runtime.getAvailable();
+		expect(runtime.getError()).toBeUndefined();
+
+		gate.resolve();
+		await expect(staleRefresh).rejects.toThrow("stale provider availability failure");
+		expect(runtime.getError()).toBeUndefined();
+	});
+});

packages/coding-agent/test/suite/regressions/7443-model-command-cached-match.test.ts

@@ -0,0 +1,46 @@
+import type { Api, Model } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { InteractiveMode } from "../../../src/modes/interactive/interactive-mode.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+const findExactModelMatch = Reflect.get(InteractiveMode.prototype, "findExactModelMatch") as (
+	this: object,
+	searchTerm: string,
+) => Promise<Model<Api> | undefined>;
+
+describe("issue #7443 /model cached match", () => {
+	let harness: Harness | undefined;
+
+	afterEach(() => {
+		harness?.cleanup();
+		harness = undefined;
+		vi.restoreAllMocks();
+	});
+
+	it("matches the availability snapshot without starting a catalog refresh", async () => {
+		harness = await createHarness({ models: [{ id: "cached", name: "Cached" }] });
+		const refresh = vi.spyOn(harness.session.modelRuntime, "refresh").mockImplementation(() => new Promise(() => {}));
+		const context = { session: harness.session, showStatus: vi.fn(), showWarning: vi.fn() };
+
+		const model = await findExactModelMatch.call(context, harness.models[0].id);
+
+		expect(model?.id).toBe("cached");
+		expect(refresh).not.toHaveBeenCalled();
+		expect(context.showStatus).not.toHaveBeenCalled();
+	});
+
+	it("uses a caller-owned deadline only after a cache miss", async () => {
+		harness = await createHarness({ models: [{ id: "cached", name: "Cached" }] });
+		const refresh = vi.spyOn(harness.session.modelRuntime, "refresh").mockResolvedValue({
+			aborted: true,
+			errors: new Map(),
+		});
+		const context = { session: harness.session, showStatus: vi.fn(), showWarning: vi.fn() };
+
+		await expect(findExactModelMatch.call(context, "not-cached")).resolves.toBeUndefined();
+
+		expect(refresh).toHaveBeenCalledOnce();
+		expect(refresh.mock.calls[0]?.[0]?.signal).toBeInstanceOf(AbortSignal);
+		expect(context.showStatus).toHaveBeenCalledWith("Refreshing model catalogs…");
+	});
+});

packages/coding-agent/test/suite/regressions/7497-session-discovery-symlink.test.ts

@@ -0,0 +1,75 @@
+import { mkdirSync, mkdtempSync, rmSync, symlinkSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { ENV_AGENT_DIR } from "../../../src/config.ts";
+import { SessionManager } from "../../../src/core/session-manager.ts";
+
+const DIRECTORY_LINK_TYPE = process.platform === "win32" ? "junction" : "dir";
+
+describe("regression #7497: discover sessions through symlinked directories", () => {
+	let tempDir: string;
+	let sessionsDir: string;
+
+	beforeEach(() => {
+		tempDir = mkdtempSync(join(tmpdir(), "pi-session-discovery-"));
+		const agentDir = join(tempDir, "agent");
+		sessionsDir = join(agentDir, "sessions");
+		mkdirSync(sessionsDir, { recursive: true });
+		vi.stubEnv(ENV_AGENT_DIR, agentDir);
+	});
+
+	afterEach(() => {
+		vi.unstubAllEnvs();
+		rmSync(tempDir, { recursive: true, force: true });
+	});
+
+	function writeSession(dir: string, id: string): void {
+		mkdirSync(dir, { recursive: true });
+		writeFileSync(
+			join(dir, `${id}.jsonl`),
+			`${JSON.stringify({
+				type: "session",
+				version: 3,
+				id,
+				timestamp: "2026-08-03T00:00:00.000Z",
+				cwd: join(tempDir, "project"),
+			})}\n`,
+		);
+	}
+
+	it("discovers a session through a directory link and preserves the alias path", async () => {
+		const targetDir = join(tempDir, "linked-sessions");
+		writeSession(targetDir, "linked");
+		const aliasDir = join(sessionsDir, "--linked--");
+		symlinkSync(targetDir, aliasDir, DIRECTORY_LINK_TYPE);
+
+		const sessions = await SessionManager.listAll();
+
+		expect(sessions.map((session) => session.id)).toEqual(["linked"]);
+		expect(sessions[0]?.path).toBe(join(aliasDir, "linked.jsonl"));
+	});
+
+	it("ignores a broken directory link without hiding valid sessions", async () => {
+		writeSession(join(sessionsDir, "--regular--"), "regular");
+		const targetDir = join(tempDir, "removed-sessions");
+		mkdirSync(targetDir);
+		symlinkSync(targetDir, join(sessionsDir, "--broken--"), DIRECTORY_LINK_TYPE);
+		rmSync(targetDir, { recursive: true });
+
+		const sessions = await SessionManager.listAll();
+
+		expect(sessions.map((session) => session.id)).toEqual(["regular"]);
+	});
+
+	it.skipIf(process.platform === "win32")("ignores links to files", async () => {
+		writeSession(join(sessionsDir, "--regular--"), "regular");
+		const targetFile = join(tempDir, "not-a-directory");
+		writeFileSync(targetFile, "");
+		symlinkSync(targetFile, join(sessionsDir, "--file--"), "file");
+
+		const sessions = await SessionManager.listAll();
+
+		expect(sessions.map((session) => session.id)).toEqual(["regular"]);
+	});
+});

packages/coding-agent/test/suite/regressions/7572-provider-retry-settings-merge.test.ts

@@ -0,0 +1,35 @@
+import { describe, expect, it } from "vitest";
+import { InMemorySettingsStorage, SettingsManager } from "../../../src/core/settings-manager.ts";
+
+describe("regression #7572: nested provider retry settings merge", () => {
+	it("preserves global provider settings not overridden by the project", () => {
+		const storage = new InMemorySettingsStorage();
+		storage.withLock("global", () =>
+			JSON.stringify({
+				retry: {
+					provider: {
+						timeoutMs: 30000,
+						maxRetryDelayMs: 45000,
+					},
+				},
+			}),
+		);
+		storage.withLock("project", () =>
+			JSON.stringify({
+				retry: {
+					provider: {
+						maxRetries: 2,
+					},
+				},
+			}),
+		);
+
+		const settingsManager = SettingsManager.fromStorage(storage);
+
+		expect(settingsManager.getProviderRetrySettings()).toEqual({
+			timeoutMs: 30000,
+			maxRetries: 2,
+			maxRetryDelayMs: 45000,
+		});
+	});
+});

packages/coding-agent/test/suite/regressions/7731-tui-method-wrapping.test.ts

@@ -0,0 +1,31 @@
+import type { TUI } from "@earendil-works/pi-tui";
+import { describe, expect, it, vi } from "vitest";
+import { createInteractiveTuiReference } from "../../../src/modes/interactive/interactive-mode.ts";
+
+describe("TUI method wrapping", () => {
+	it("calls the method captured before a replacement", () => {
+		const renderer = {
+			render: (width: number) => [`width: ${width}`],
+		} as unknown as TUI;
+		const tui = createInteractiveTuiReference(() => renderer);
+		const originalRender = tui.render;
+		tui.render = (width: number) => originalRender(width);
+
+		expect(tui.render(80)).toEqual(["width: 80"]);
+	});
+
+	it("routes a captured method to a replacement renderer", () => {
+		const regularRequestRender = vi.fn();
+		const fullscreenRequestRender = vi.fn();
+		let renderer = { requestRender: regularRequestRender } as unknown as TUI;
+		const tui = createInteractiveTuiReference(() => renderer);
+		const requestRender = tui.requestRender;
+
+		requestRender();
+		renderer = { requestRender: fullscreenRequestRender } as unknown as TUI;
+		requestRender();
+
+		expect(regularRequestRender).toHaveBeenCalledOnce();
+		expect(fullscreenRequestRender).toHaveBeenCalledOnce();
+	});
+});

packages/coding-agent/test/suite/regressions/7829-invalid-settings-warning.test.ts

@@ -0,0 +1,56 @@
+import { Container } from "@earendil-works/pi-tui";
+import { beforeAll, describe, expect, it, vi } from "vitest";
+import type { AgentSessionRuntimeDiagnostic } from "../../../src/core/agent-session-services.ts";
+import { InteractiveMode } from "../../../src/modes/interactive/interactive-mode.ts";
+import { initTheme } from "../../../src/modes/interactive/theme/theme.ts";
+import { createHarness } from "../harness.ts";
+
+function render(container: Container): string {
+	return container.children.flatMap((child) => child.render(120)).join("\n");
+}
+
+describe("issue #7829 invalid settings warning", () => {
+	beforeAll(() => initTheme("dark"));
+
+	it("renders startup diagnostics inside the transcript", async () => {
+		const harness = await createHarness();
+		const previousOffline = process.env.PI_OFFLINE;
+		process.env.PI_OFFLINE = "1";
+		try {
+			const chatContainer = new Container();
+			const startupDiagnostics: AgentSessionRuntimeDiagnostic[] = [
+				{
+					type: "warning",
+					message: "Invalid settings file /tmp/settings.json: malformed JSON",
+				},
+			];
+			const context = {
+				init: vi.fn(async () => {}),
+				options: { startupDiagnostics },
+				chatContainer,
+				outputPad: 1,
+				ui: { requestRender: vi.fn() },
+				version: "test",
+				showWarning: (InteractiveMode.prototype as unknown as { showWarning(message: string): void }).showWarning,
+				session: harness.session,
+				checkForPackageUpdates: vi.fn().mockResolvedValue([]),
+				checkTmuxKeyboardSetup: vi.fn().mockResolvedValue(undefined),
+				maybeWarnAboutAnthropicSubscriptionAuth: vi.fn(),
+				getUserInput: vi.fn(() => new Promise<string>(() => {})),
+			};
+			const run = (InteractiveMode.prototype as unknown as { run(this: typeof context): Promise<void> }).run;
+
+			void run.call(context);
+
+			await vi.waitFor(() => {
+				expect(render(chatContainer)).toContain(
+					"Warning: Invalid settings file /tmp/settings.json: malformed JSON",
+				);
+			});
+		} finally {
+			if (previousOffline === undefined) delete process.env.PI_OFFLINE;
+			else process.env.PI_OFFLINE = previousOffline;
+			harness.cleanup();
+		}
+	});
+});

packages/coding-agent/test/suite/regressions/7911-json-stream-usage.test.ts

@@ -0,0 +1,32 @@
+import { fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import { toJsonEvent } from "../../../src/modes/json-event.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+describe("regression #7911: JSON message updates retain usage", () => {
+	let harness: Harness | undefined;
+
+	afterEach(() => {
+		harness?.cleanup();
+	});
+
+	it("includes cumulative usage without cumulative message snapshots", async () => {
+		harness = await createHarness();
+		harness.setResponses([fauxAssistantMessage("hello")]);
+
+		await harness.session.prompt("respond");
+
+		// #7290's delta-only wire projection dropped this fixed-size metadata with the snapshots.
+		const update = harness
+			.eventsOfType("message_update")
+			.find((event) => event.message.role === "assistant" && event.message.usage.totalTokens > 0);
+		if (!update || update.message.role !== "assistant") {
+			throw new Error("Expected an assistant update with populated usage");
+		}
+
+		const wireUpdate = toJsonEvent(update);
+		expect(wireUpdate.usage).toEqual(update.message.usage);
+		expect(wireUpdate).not.toHaveProperty("message");
+		expect(wireUpdate.assistantMessageEvent).not.toHaveProperty("partial");
+	});
+});

packages/coding-agent/test/suite/regressions/7925-toolcall-start-metadata.test.ts

@@ -0,0 +1,43 @@
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import { toJsonEvent } from "../../../src/modes/json-event.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+describe("regression #7925: tool-call metadata is available when streaming starts", () => {
+	let harness: Harness | undefined;
+
+	afterEach(() => {
+		harness?.cleanup();
+	});
+
+	it("includes the tool call id and name without cumulative snapshots", async () => {
+		harness = await createHarness();
+		harness.setResponses([
+			fauxAssistantMessage(
+				fauxToolCall("write", { path: "output.txt", content: "x".repeat(100) }, { id: "call_7925" }),
+				{ stopReason: "toolUse" },
+			),
+			fauxAssistantMessage("done"),
+		]);
+
+		await harness.session.prompt("write a file");
+
+		const update = harness
+			.eventsOfType("message_update")
+			.find((event) => event.assistantMessageEvent.type === "toolcall_start");
+		if (!update || update.message.role !== "assistant") {
+			throw new Error("Expected toolcall_start assistant update");
+		}
+
+		expect(toJsonEvent(update)).toEqual({
+			type: "message_update",
+			usage: update.message.usage,
+			assistantMessageEvent: {
+				type: "toolcall_start",
+				contentIndex: 0,
+				id: "call_7925",
+				toolName: "write",
+			},
+		});
+	});
+});

packages/coding-agent/test/suite/regressions/8237-node-sea-extension-loading.test.ts

@@ -0,0 +1,50 @@
+import { afterAll, describe, expect, it, vi } from "vitest";
+
+const state = vi.hoisted(() => {
+	const originalGetBuiltinModule = Object.getOwnPropertyDescriptor(process, "getBuiltinModule");
+	const getBuiltinModule = process.getBuiltinModule.bind(process);
+	Object.defineProperty(process, "getBuiltinModule", {
+		configurable: true,
+		value: (id: string) => (id === "node:sea" ? { isSea: () => true } : getBuiltinModule(id)),
+	});
+	return {
+		originalGetBuiltinModule,
+		createJiti: vi.fn((_id: unknown, _options: unknown) => ({
+			import: vi.fn(async () => () => {}),
+		})),
+	};
+});
+
+vi.mock("jiti/static", () => ({ createJiti: state.createJiti }));
+
+import { loadExtensions } from "../../../src/core/extensions/loader.ts";
+
+interface JitiOptionsProbe {
+	alias?: unknown;
+	tryNative?: boolean;
+	virtualModules?: Record<string, unknown>;
+}
+
+afterAll(() => {
+	if (state.originalGetBuiltinModule) {
+		Object.defineProperty(process, "getBuiltinModule", state.originalGetBuiltinModule);
+	}
+});
+
+describe("Node SEA extension loading", () => {
+	it("uses bundled virtual modules instead of filesystem aliases", async () => {
+		const result = await loadExtensions(["/extension.ts"], "/");
+
+		expect(result.errors).toEqual([]);
+		expect(result.extensions).toHaveLength(1);
+		expect(state.createJiti).toHaveBeenCalledOnce();
+
+		const options = state.createJiti.mock.calls[0][1] as JitiOptionsProbe;
+		// Source TypeScript also uses virtual modules, so tryNative: false is what
+		// proves the compiled-binary branch took precedence over the source branch.
+		expect(options.tryNative).toBe(false);
+		expect(options.alias).toBeUndefined();
+		expect(options.virtualModules?.typebox).toBeDefined();
+		expect(options.virtualModules?.["@earendil-works/pi-coding-agent"]).toBeDefined();
+	});
+});

packages/coding-agent/test/suite/regressions/8261-subagent-project-trust.test.ts

@@ -0,0 +1,82 @@
+import { mkdirSync, writeFileSync } from "node:fs";
+import { join } from "node:path";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { describe, expect, it, vi } from "vitest";
+import subagentExtension from "../../../examples/extensions/subagent/index.ts";
+import type { ExtensionUIContext } from "../../../src/core/extensions/index.ts";
+import { createHarness, getMessageText } from "../harness.ts";
+
+vi.mock("@earendil-works/pi-coding-agent", () => ({
+	CONFIG_DIR_NAME: ".pi",
+	getAgentDir: () => "/missing-user-agent-dir",
+	getMarkdownTheme: () => ({}),
+	parseFrontmatter: (content: string) => ({
+		frontmatter: { name: "project-agent", description: "Project test agent" },
+		body: content,
+	}),
+	withFileMutationQueue: async (_path: string, fn: () => Promise<unknown>) => fn(),
+}));
+
+interface RunOptions {
+	trusted: boolean;
+	confirmResult?: boolean;
+}
+
+async function runProjectAgent(options: RunOptions): Promise<{ confirmCalls: number; toolResult: string }> {
+	const harness = await createHarness({ extensionFactories: [subagentExtension] });
+	const confirm = vi.fn(async () => options.confirmResult ?? false);
+
+	try {
+		const agentsDir = join(harness.tempDir, ".pi", "agents");
+		mkdirSync(agentsDir, { recursive: true });
+		writeFileSync(
+			join(agentsDir, "project-agent.md"),
+			"---\nname: project-agent\ndescription: Project test agent\n---\n\nHandle the delegated task.\n",
+		);
+		harness.settingsManager.setProjectTrusted(options.trusted);
+
+		await harness.session.bindExtensions({
+			uiContext: { confirm } as unknown as ExtensionUIContext,
+			mode: "tui",
+		});
+
+		harness.setResponses([
+			fauxAssistantMessage(
+				fauxToolCall("subagent", {
+					agent: "project-agent",
+					task: "Test project trust",
+					agentScope: "project",
+					cwd: join(harness.tempDir, "missing-cwd"),
+				}),
+				{ stopReason: "toolUse" },
+			),
+			fauxAssistantMessage("done"),
+		]);
+
+		await harness.session.prompt("Delegate this task");
+
+		const toolResult = harness.session.messages.find((message) => message.role === "toolResult");
+		return {
+			confirmCalls: confirm.mock.calls.length,
+			toolResult: getMessageText(toolResult),
+		};
+	} finally {
+		harness.cleanup();
+	}
+}
+
+describe("regression #8261: subagent project trust", () => {
+	it("skips per-call confirmation for trusted projects", async () => {
+		const result = await runProjectAgent({ trusted: true });
+
+		expect(result.confirmCalls).toBe(0);
+		expect(result.toolResult).not.toContain("Canceled:");
+	});
+
+	it("keeps confirmation for untrusted interactive projects", async () => {
+		const result = await runProjectAgent({ trusted: false, confirmResult: false });
+
+		expect(result.confirmCalls).toBe(1);
+		expect(result.toolResult).toContain("Canceled: project-local agents not approved.");
+	});
+});

packages/coding-agent/test/suite/regressions/8328-zero-usage-auto-compaction.test.ts

@@ -0,0 +1,80 @@
+import type { AssistantMessage } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { createHarness, type Harness } from "../harness.ts";
+
+type SessionWithCompactionInternals = {
+	_checkCompaction: (assistantMessage: AssistantMessage) => Promise<boolean>;
+	_runAutoCompaction: (reason: "overflow" | "threshold", willRetry: boolean) => Promise<boolean>;
+};
+
+function createZeroUsageAssistant(harness: Harness): AssistantMessage {
+	const model = harness.getModel();
+	return {
+		role: "assistant",
+		content: [{ type: "text", text: "response" }],
+		api: model.api,
+		provider: model.provider,
+		model: model.id,
+		usage: {
+			input: 0,
+			output: 0,
+			cacheRead: 0,
+			cacheWrite: 0,
+			totalTokens: 0,
+			cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+		},
+		stopReason: "stop",
+		timestamp: Date.now(),
+	};
+}
+
+describe("issue #8328 zero-usage auto-compaction", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		vi.restoreAllMocks();
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	async function createCompactionHarness(): Promise<Harness> {
+		const harness = await createHarness({
+			models: [{ id: "faux-1", contextWindow: 100, maxTokens: 20 }],
+			settings: { compaction: { enabled: true, reserveTokens: 10 } },
+		});
+		harnesses.push(harness);
+		return harness;
+	}
+
+	it("uses the message estimate when no assistant has reported usage", async () => {
+		const harness = await createCompactionHarness();
+		const assistant = createZeroUsageAssistant(harness);
+		harness.session.agent.state.messages = [
+			{ role: "user", content: [{ type: "text", text: "x".repeat(400) }], timestamp: Date.now() - 1 },
+			assistant,
+		];
+		const sessionInternals = harness.session as unknown as SessionWithCompactionInternals;
+		const runAutoCompactionSpy = vi.spyOn(sessionInternals, "_runAutoCompaction").mockResolvedValue(false);
+
+		await sessionInternals._checkCompaction(assistant);
+
+		expect(runAutoCompactionSpy).toHaveBeenCalledOnce();
+		expect(runAutoCompactionSpy).toHaveBeenCalledWith("threshold", false);
+	});
+
+	it("does not compact when the zero-usage message estimate is below the threshold", async () => {
+		const harness = await createCompactionHarness();
+		const assistant = createZeroUsageAssistant(harness);
+		harness.session.agent.state.messages = [
+			{ role: "user", content: [{ type: "text", text: "short" }], timestamp: Date.now() - 1 },
+			assistant,
+		];
+		const sessionInternals = harness.session as unknown as SessionWithCompactionInternals;
+		const runAutoCompactionSpy = vi.spyOn(sessionInternals, "_runAutoCompaction").mockResolvedValue(false);
+
+		await sessionInternals._checkCompaction(assistant);
+
+		expect(runAutoCompactionSpy).not.toHaveBeenCalled();
+	});
+});

packages/coding-agent/test/suite/regressions/8337-utf8-bom-parsing.test.ts

@@ -0,0 +1,49 @@
+import { existsSync, mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { SettingsManager } from "../../../src/core/settings-manager.ts";
+import { parseFrontmatter } from "../../../src/utils/frontmatter.ts";
+import { splitBom } from "../../../src/utils/text.ts";
+
+describe("issue #8337 UTF-8 BOM parsing", () => {
+	let testDir: string;
+
+	beforeEach(() => {
+		testDir = mkdtempSync(join(tmpdir(), "pi-8337-"));
+	});
+
+	afterEach(() => {
+		if (existsSync(testDir)) {
+			rmSync(testDir, { recursive: true, force: true });
+		}
+	});
+
+	it("loads frontmatter and settings with a leading BOM", async () => {
+		expect(splitBom("\uFEFFcontent")).toEqual({ bom: "\uFEFF", text: "content" });
+		const document = "---\nname: demo\ndescription: Test\n---\nBody";
+		expect(parseFrontmatter(`\uFEFF${document}`)).toEqual({
+			frontmatter: { name: "demo", description: "Test" },
+			body: "Body",
+		});
+
+		const agentDir = join(testDir, "agent");
+		const projectDir = join(testDir, "project");
+		mkdirSync(join(projectDir, ".pi"), { recursive: true });
+		mkdirSync(agentDir, { recursive: true });
+		const globalSettingsPath = join(agentDir, "settings.json");
+		writeFileSync(globalSettingsPath, `\uFEFF${JSON.stringify({ defaultModel: "global-model" })}`);
+		writeFileSync(
+			join(projectDir, ".pi", "settings.json"),
+			`\uFEFF${JSON.stringify({ defaultProvider: "project-provider" })}`,
+		);
+
+		const settings = SettingsManager.create(projectDir, agentDir);
+		expect(settings.getDefaultModel()).toBe("global-model");
+		expect(settings.getDefaultProvider()).toBe("project-provider");
+
+		settings.setTheme("dark");
+		await settings.flush();
+		expect(readFileSync(globalSettingsPath, "utf-8")).not.toMatch(/^\uFEFF/);
+	});
+});

packages/coding-agent/test/suite/regressions/8423-extension-factory-failure.test.ts

@@ -0,0 +1,88 @@
+import { describe, expect, it } from "vitest";
+import { createEventBus } from "../../../src/core/event-bus.ts";
+import { createExtensionRuntime, loadExtensionFromFactory } from "../../../src/core/extensions/loader.ts";
+import type { ExtensionAPI, ProviderConfig } from "../../../src/core/extensions/types.ts";
+
+const providerConfig = {
+	baseUrl: "https://provider.test/v1",
+	apiKey: "provider-test-key",
+} satisfies ProviderConfig;
+
+describe("issue #8423 extension factory failure", () => {
+	it("discards runtime changes and disables the failed API", async () => {
+		const runtime = createExtensionRuntime();
+		const eventBus = createEventBus();
+		let capturedApi: ExtensionAPI | undefined;
+		let eventCalls = 0;
+		let flagDuringLoad: boolean | string | undefined;
+
+		await loadExtensionFromFactory(
+			(pi) => pi.registerProvider("working-provider", providerConfig),
+			process.cwd(),
+			eventBus,
+			runtime,
+			"<working>",
+		);
+		await expect(
+			loadExtensionFromFactory(
+				(pi) => {
+					capturedApi = pi;
+					pi.events.on("factory-failure", () => {
+						eventCalls++;
+					});
+					pi.registerFlag("failed-flag", { type: "boolean", default: true });
+					flagDuringLoad = pi.getFlag("failed-flag");
+					pi.unregisterProvider("working-provider");
+					pi.registerProvider("failed-provider", providerConfig);
+					throw new Error("factory failed");
+				},
+				process.cwd(),
+				eventBus,
+				runtime,
+				"<failing>",
+			),
+		).rejects.toThrow("factory failed");
+
+		eventBus.emit("factory-failure", undefined);
+		expect(flagDuringLoad).toBe(true);
+		expect(runtime.flagValues.has("failed-flag")).toBe(false);
+		expect(runtime.pendingProviderRegistrations.map(({ name }) => name)).toEqual(["working-provider"]);
+		expect(eventCalls).toBe(0);
+		expect(capturedApi).toBeDefined();
+		expect(() => capturedApi?.registerFlag("late-flag", { type: "boolean", default: true })).toThrow(
+			'Extension "<failing>" failed to load and its API is no longer active.',
+		);
+	});
+
+	it("does not discard a concurrently loaded factory's provider", async () => {
+		const runtime = createExtensionRuntime();
+		const eventBus = createEventBus();
+		let releaseFailure!: () => void;
+		const waitBeforeFailure = new Promise<void>((resolve) => {
+			releaseFailure = resolve;
+		});
+		const failingLoad = loadExtensionFromFactory(
+			async (pi) => {
+				pi.registerProvider("failed-provider", providerConfig);
+				await waitBeforeFailure;
+				throw new Error("factory failed");
+			},
+			process.cwd(),
+			eventBus,
+			runtime,
+			"<failing>",
+		);
+
+		await loadExtensionFromFactory(
+			(pi) => pi.registerProvider("working-provider", providerConfig),
+			process.cwd(),
+			eventBus,
+			runtime,
+			"<working>",
+		);
+		releaseFailure();
+
+		await expect(failingLoad).rejects.toThrow("factory failed");
+		expect(runtime.pendingProviderRegistrations.map(({ name }) => name)).toEqual(["working-provider"]);
+	});
+});

packages/coding-agent/test/suite/regressions/8537-custom-message-tool-result-ordering.test.ts

@@ -0,0 +1,144 @@
+import type { AgentMessage, AgentTool } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import { convertToLlm } from "../../../src/core/messages.ts";
+import { createHarness, type Harness } from "../harness.ts";
+
+function roles(messages: AgentMessage[]): string[] {
+	return messages.map((message) => message.role);
+}
+
+describe("#8537 custom messages injected during tool execution", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("appends the message after the turn's tool results instead of between call and result", async () => {
+		let notify: (() => Promise<void>) | undefined;
+		const slowTool: AgentTool = {
+			name: "wait",
+			label: "Wait",
+			description: "Wait for a background task",
+			parameters: Type.Object({}),
+			execute: async () => {
+				// A background task (e.g. a subagent reply) notifies the session while the
+				// tool is still running.
+				await notify?.();
+				return { content: [{ type: "text", text: "tool done" }], details: {} };
+			},
+		};
+
+		const harness = await createHarness({ tools: [slowTool] });
+		harnesses.push(harness);
+		notify = () =>
+			harness.session.sendCustomMessage(
+				{ customType: "subagent-reply", content: "subagent replied", display: true },
+				{ triggerTurn: false },
+			);
+
+		harness.setResponses([
+			fauxAssistantMessage([fauxToolCall("wait", {})], { stopReason: "toolUse" }),
+			fauxAssistantMessage("done"),
+		]);
+
+		await harness.session.prompt("hi");
+
+		expect(roles(harness.session.messages)).toEqual(["user", "assistant", "toolResult", "custom", "assistant"]);
+	});
+
+	it("keeps session entries and message events in the same order as agent state", async () => {
+		let notify: (() => Promise<void>) | undefined;
+		const slowTool: AgentTool = {
+			name: "wait",
+			label: "Wait",
+			description: "Wait for a background task",
+			parameters: Type.Object({}),
+			execute: async () => {
+				await notify?.();
+				return { content: [{ type: "text", text: "tool done" }], details: {} };
+			},
+		};
+
+		const harness = await createHarness({ tools: [slowTool] });
+		harnesses.push(harness);
+		notify = () =>
+			harness.session.sendCustomMessage(
+				{ customType: "subagent-reply", content: "subagent replied", display: true },
+				{ triggerTurn: false },
+			);
+
+		harness.setResponses([
+			fauxAssistantMessage([fauxToolCall("wait", {})], { stopReason: "toolUse" }),
+			fauxAssistantMessage("done"),
+		]);
+
+		await harness.session.prompt("hi");
+
+		const entryKinds = harness.sessionManager
+			.getBranch()
+			.flatMap((entry) =>
+				entry.type === "message" ? [entry.message.role] : entry.type === "custom_message" ? ["custom"] : [],
+			);
+		expect(entryKinds).toEqual(["user", "assistant", "toolResult", "custom", "assistant"]);
+
+		// message events must never describe a message the session tree does not contain yet
+		const messageStarts = harness.events.flatMap((event) =>
+			event.type === "message_start" ? [event.message.role] : [],
+		);
+		expect(messageStarts).toEqual(["user", "assistant", "toolResult", "custom", "assistant"]);
+	});
+
+	it("produces an llm history where every tool result follows its tool call", async () => {
+		let notify: (() => Promise<void>) | undefined;
+		const slowTool: AgentTool = {
+			name: "wait",
+			label: "Wait",
+			description: "Wait for a background task",
+			parameters: Type.Object({}),
+			execute: async () => {
+				await notify?.();
+				return { content: [{ type: "text", text: "tool done" }], details: {} };
+			},
+		};
+
+		const harness = await createHarness({ tools: [slowTool] });
+		harnesses.push(harness);
+		notify = () =>
+			harness.session.sendCustomMessage(
+				{ customType: "subagent-reply", content: "subagent replied", display: true },
+				{ triggerTurn: false },
+			);
+
+		harness.setResponses([
+			fauxAssistantMessage([fauxToolCall("wait", {})], { stopReason: "toolUse" }),
+			fauxAssistantMessage("done"),
+			fauxAssistantMessage("second turn"),
+		]);
+
+		await harness.session.prompt("hi");
+		await harness.session.prompt("and now?");
+
+		const llmMessages = convertToLlm(harness.session.messages);
+		const openToolCallIds = new Set<string>();
+		for (const message of llmMessages) {
+			if (message.role === "assistant") {
+				openToolCallIds.clear();
+				for (const block of message.content) {
+					if (block.type === "toolCall") openToolCallIds.add(block.id);
+				}
+				continue;
+			}
+			if (message.role === "toolResult") {
+				expect(openToolCallIds.has(message.toolCallId)).toBe(true);
+				openToolCallIds.delete(message.toolCallId);
+				continue;
+			}
+			openToolCallIds.clear();
+		}
+	});
+});

packages/coding-agent/test/suite/regressions/8611-thinking-toggle-pending-bash-output.test.ts

@@ -0,0 +1,68 @@
+import { Container, type TUI } from "@earendil-works/pi-tui";
+import { beforeAll, describe, expect, test, vi } from "vitest";
+import { ToolExecutionComponent } from "../../../src/modes/interactive/components/tool-execution.ts";
+import { InteractiveMode } from "../../../src/modes/interactive/interactive-mode.ts";
+import { initTheme } from "../../../src/modes/interactive/theme/theme.ts";
+import { stripAnsi } from "../../../src/utils/ansi.ts";
+
+type UpdateThinkingBlockVisibility = (this: { chatContainer: Container; ui: TUI }) => void;
+
+type ToggleThinkingBlockVisibility = (this: {
+	hideThinkingBlock: boolean;
+	settingsManager: { setHideThinkingBlock(hidden: boolean): void };
+	updateThinkingBlockVisibility(): void;
+	showStatus(message: string): void;
+}) => void;
+
+function renderChat(container: Container): string {
+	return stripAnsi(container.render(120).join("\n"));
+}
+
+describe("thinking visibility while a bash tool is running (#8611)", () => {
+	beforeAll(() => {
+		initTheme("dark");
+	});
+
+	test("preserves partial bash output", () => {
+		const ui = { requestRender: vi.fn() } as unknown as TUI;
+		const chatContainer = new Container();
+		const component = new ToolExecutionComponent(
+			"bash",
+			"tool-8611",
+			{ command: "echo first; sleep 10" },
+			{ showImages: false },
+			undefined,
+			ui,
+			process.cwd(),
+		);
+		component.markExecutionStarted();
+		component.updateResult({ content: [{ type: "text", text: "first" }], isError: false }, true);
+		chatContainer.addChild(component);
+
+		const updateThinkingBlockVisibility = Reflect.get(
+			InteractiveMode.prototype,
+			"updateThinkingBlockVisibility",
+		) as UpdateThinkingBlockVisibility;
+		const toggleThinkingBlockVisibility = Reflect.get(
+			InteractiveMode.prototype,
+			"toggleThinkingBlockVisibility",
+		) as ToggleThinkingBlockVisibility;
+		const fakeThis = {
+			hideThinkingBlock: false,
+			settingsManager: { setHideThinkingBlock: vi.fn() },
+			chatContainer,
+			ui,
+			updateThinkingBlockVisibility() {
+				updateThinkingBlockVisibility.call(this);
+			},
+			showStatus: vi.fn(),
+		};
+
+		expect(renderChat(chatContainer)).toContain("first");
+		toggleThinkingBlockVisibility.call(fakeThis);
+
+		expect(fakeThis.settingsManager.setHideThinkingBlock).toHaveBeenCalledWith(true);
+		expect(chatContainer.children).toContain(component);
+		expect(renderChat(chatContainer)).toContain("first");
+	});
+});

packages/coding-agent/test/suite/regressions/8724-in-memory-fork-active-tool.test.ts

@@ -0,0 +1,100 @@
+import type { AgentTool, AgentToolResult } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import {
+	AgentSessionRuntime,
+	type AgentSessionServices,
+	type CreateAgentSessionRuntimeFactory,
+	createAgentSessionFromServices,
+} from "../../../src/core/agent-session-runtime.ts";
+import { createHarness } from "../harness.ts";
+
+describe("regression #8724: in-memory fork during an active tool turn", () => {
+	const cleanups: Array<() => Promise<void> | void> = [];
+
+	afterEach(async () => {
+		while (cleanups.length > 0) {
+			await cleanups.pop()?.();
+		}
+	});
+
+	it("does not append the aborted turn to the replacement session", async () => {
+		let markToolStarted = () => {};
+		const toolStarted = new Promise<void>((resolve) => {
+			markToolStarted = resolve;
+		});
+		const blockingTool: AgentTool = {
+			name: "block",
+			label: "Block",
+			description: "Wait until aborted",
+			parameters: Type.Object({}),
+			execute: (_toolCallId, _params, signal) =>
+				new Promise<AgentToolResult<unknown>>((resolve) => {
+					markToolStarted();
+					signal?.addEventListener(
+						"abort",
+						() => resolve({ content: [{ type: "text", text: "tool aborted" }], details: {} }),
+						{ once: true },
+					);
+				}),
+		};
+		const harness = await createHarness({ tools: [blockingTool] });
+		const services: AgentSessionServices = {
+			cwd: harness.tempDir,
+			agentDir: harness.tempDir,
+			modelRuntime: harness.session.modelRuntime,
+			settingsManager: harness.settingsManager,
+			resourceLoader: harness.session.resourceLoader,
+			diagnostics: [],
+		};
+		const createRuntime: CreateAgentSessionRuntimeFactory = async ({ sessionManager, sessionStartEvent }) => ({
+			...(await createAgentSessionFromServices({
+				services,
+				sessionManager,
+				sessionStartEvent,
+				model: harness.getModel(),
+				noTools: "all",
+			})),
+			services,
+			diagnostics: [],
+		});
+		const runtime = new AgentSessionRuntime(harness.session, services, createRuntime);
+		cleanups.push(async () => {
+			if (runtime.session !== harness.session) {
+				await runtime.dispose();
+			}
+			harness.cleanup();
+		});
+
+		harness.setResponses([
+			fauxAssistantMessage("first response"),
+			fauxAssistantMessage(fauxToolCall("block", {}), { stopReason: "toolUse" }),
+			fauxAssistantMessage("unused after abort"),
+		]);
+		await runtime.session.prompt("first prompt");
+		const firstUserEntryId = runtime.session.getUserMessagesForForking()[0]?.entryId;
+		expect(firstUserEntryId).toBeDefined();
+
+		const outgoingPrompt = runtime.session.prompt("start blocking tool");
+		await toolStarted;
+		const forkResult = await runtime.fork(firstUserEntryId!);
+		await outgoingPrompt;
+		await runtime.session.bindExtensions({});
+
+		expect(forkResult).toEqual({ cancelled: false, selectedText: "first prompt" });
+		expect(runtime.session.messages).toEqual([]);
+		expect(runtime.session.sessionManager.getEntries().filter((entry) => entry.type === "message")).toEqual([]);
+
+		let capturedRoles: string[] = [];
+		harness.setResponses([
+			(context) => {
+				capturedRoles = context.messages.map((message) => message.role);
+				return fauxAssistantMessage("next response");
+			},
+		]);
+		await runtime.session.prompt("next prompt");
+
+		expect(capturedRoles).toEqual(["user"]);
+	});
+});

packages/coding-agent/test/suite/regressions/8935-parallel-preflight-abort.test.ts

@@ -0,0 +1,72 @@
+import type { AgentTool } from "@earendil-works/pi-agent-core";
+import { fauxAssistantMessage, fauxToolCall } from "@earendil-works/pi-ai";
+import { Type } from "typebox";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, getMessageText, type Harness } from "../harness.ts";
+
+describe("#8935 parallel preflight abort", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("does not start prepared tools after a later preflight aborts", async () => {
+		const executions: string[] = [];
+		const preflights: string[] = [];
+		const resultHooks: string[] = [];
+		const externalWrite: AgentTool = {
+			name: "external_write",
+			label: "External write",
+			description: "Perform an external write",
+			parameters: Type.Object({ value: Type.String() }),
+			execute: async (_toolCallId, params) => {
+				const value =
+					typeof params === "object" && params !== null && "value" in params ? String(params.value) : "";
+				executions.push(value);
+				return { content: [{ type: "text", text: value }], details: { value } };
+			},
+		};
+		const harness = await createHarness({
+			tools: [externalWrite],
+			extensionFactories: [
+				(pi) => {
+					pi.on("tool_call", async (event, ctx) => {
+						const value = "value" in event.input ? String(event.input.value) : "";
+						preflights.push(value);
+						if (value === "second") ctx.abort();
+					});
+					pi.on("tool_result", async (event) => {
+						resultHooks.push(event.toolCallId);
+					});
+				},
+			],
+		});
+		harnesses.push(harness);
+		harness.setResponses([
+			fauxAssistantMessage(
+				[fauxToolCall("external_write", { value: "first" }), fauxToolCall("external_write", { value: "second" })],
+				{ stopReason: "toolUse" },
+			),
+		]);
+
+		await harness.session.prompt("run both writes");
+
+		expect(preflights).toEqual(["first", "second"]);
+		expect(executions).toEqual([]);
+		expect(resultHooks).toEqual([]);
+
+		const starts = harness.eventsOfType("tool_execution_start");
+		const ends = harness.eventsOfType("tool_execution_end");
+		expect(starts).toHaveLength(2);
+		expect(ends).toHaveLength(2);
+		expect(new Set(ends.map((event) => event.toolCallId))).toEqual(new Set(starts.map((event) => event.toolCallId)));
+		expect(ends.every((event) => event.isError)).toBe(true);
+
+		const toolResults = harness.session.messages.filter((message) => message.role === "toolResult");
+		expect(toolResults.map((message) => message.toolCallId)).toEqual(starts.map((event) => event.toolCallId));
+		expect(toolResults.map(getMessageText)).toEqual(["Operation aborted", "Operation aborted"]);
+	});
+});

packages/coding-agent/test/suite/regressions/8989-fork-compaction-label-boundary.test.ts

@@ -0,0 +1,24 @@
+import { describe, expect, it } from "vitest";
+import { type CompactionEntry, SessionManager } from "../../../src/core/session-manager.ts";
+import { userMsg } from "../../utilities.ts";
+
+describe("regression #8989", () => {
+	it("preserves compaction context when a fork removes the boundary label", () => {
+		const session = SessionManager.inMemory();
+		const oldId = session.appendMessage(userMsg("old"));
+		// findCutPoint() can move a compaction boundary back to this context-invisible label.
+		const labelId = session.appendLabelChange(oldId, "checkpoint");
+		const keptId = session.appendMessage(userMsg("kept"));
+		const compactionId = session.appendCompaction("summary", labelId, 100);
+		const leafId = session.appendMessage(userMsg("after"));
+
+		session.createBranchedSession(leafId);
+
+		expect((session.getEntry(compactionId) as CompactionEntry).firstKeptEntryId).toBe(keptId);
+		expect(session.buildSessionContext().messages).toMatchObject([
+			{ role: "compactionSummary", summary: "summary" },
+			{ role: "user", content: "kept" },
+			{ role: "user", content: "after" },
+		]);
+	});
+});

packages/coding-agent/test/suite/regressions/extension-factory-cache.test.ts

@@ -0,0 +1,131 @@
+import { existsSync, mkdirSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { clearExtensionCache, loadExtensions, loadExtensionsCached } from "../../../src/core/extensions/loader.ts";
+import { DefaultResourceLoader } from "../../../src/core/resource-loader.ts";
+
+interface TestState {
+	moduleLoads?: number;
+	factoryRuns?: number;
+}
+
+function state(): TestState {
+	const global = globalThis as typeof globalThis & { __extensionFactoryCacheTest?: TestState };
+	if (!global.__extensionFactoryCacheTest) {
+		global.__extensionFactoryCacheTest = {};
+	}
+	return global.__extensionFactoryCacheTest;
+}
+
+function resetState(): void {
+	delete (globalThis as typeof globalThis & { __extensionFactoryCacheTest?: TestState }).__extensionFactoryCacheTest;
+}
+
+function writeCountingExtension(filePath: string): void {
+	writeFileSync(
+		filePath,
+		`
+const state = (globalThis.__extensionFactoryCacheTest ??= {});
+state.moduleLoads = (state.moduleLoads ?? 0) + 1;
+
+export default function () {
+	state.factoryRuns = (state.factoryRuns ?? 0) + 1;
+}
+`,
+		"utf-8",
+	);
+}
+
+describe("extension factory cache", () => {
+	const roots: string[] = [];
+
+	function fixture(name: string) {
+		const root = join(tmpdir(), `pi-extension-cache-${name}-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		const cwd = join(root, "project");
+		const agentDir = join(root, "agent");
+		mkdirSync(cwd, { recursive: true });
+		mkdirSync(agentDir, { recursive: true });
+		roots.push(root);
+		return { root, cwd, agentDir };
+	}
+
+	beforeEach(() => {
+		resetState();
+		clearExtensionCache();
+	});
+
+	afterEach(() => {
+		while (roots.length > 0) {
+			const root = roots.pop();
+			if (root && existsSync(root)) {
+				rmSync(root, { recursive: true, force: true });
+			}
+		}
+		resetState();
+		clearExtensionCache();
+	});
+
+	it("caches extension modules for cached same-cwd loads but reruns factories", async () => {
+		const { root, cwd } = fixture("same-cwd");
+		const extensionPath = join(root, "counting.ts");
+		writeCountingExtension(extensionPath);
+
+		const first = await loadExtensionsCached([extensionPath], cwd);
+		const second = await loadExtensionsCached([extensionPath], cwd);
+
+		expect(state().moduleLoads).toBe(1);
+		expect(state().factoryRuns).toBe(2);
+		expect(first.extensions[0]).not.toBe(second.extensions[0]);
+		expect(first.runtime).not.toBe(second.runtime);
+	});
+
+	it("does not cache direct loadExtensions calls", async () => {
+		const { root, cwd } = fixture("direct");
+		const extensionPath = join(root, "counting.ts");
+		writeCountingExtension(extensionPath);
+
+		await loadExtensions([extensionPath], cwd);
+		await loadExtensions([extensionPath], cwd);
+
+		expect(state().moduleLoads).toBe(2);
+		expect(state().factoryRuns).toBe(2);
+	});
+
+	it("clears the cache on resource loader reload", async () => {
+		const { cwd, agentDir } = fixture("reload");
+		const extensionDir = join(agentDir, "extensions");
+		mkdirSync(extensionDir, { recursive: true });
+		writeCountingExtension(join(extensionDir, "counting.ts"));
+		const loader = new DefaultResourceLoader({
+			cwd,
+			agentDir,
+			noSkills: true,
+			noPromptTemplates: true,
+			noThemes: true,
+		});
+
+		await loader.reload();
+		await loader.reload();
+
+		expect(state().moduleLoads).toBe(2);
+		expect(state().factoryRuns).toBe(2);
+	});
+
+	it("keeps the cache scoped to one cwd", async () => {
+		const { root } = fixture("cross-cwd");
+		const firstCwd = join(root, "first");
+		const secondCwd = join(root, "second");
+		mkdirSync(firstCwd, { recursive: true });
+		mkdirSync(secondCwd, { recursive: true });
+		const extensionPath = join(root, "counting.ts");
+		writeCountingExtension(extensionPath);
+
+		await loadExtensionsCached([extensionPath], firstCwd);
+		await loadExtensionsCached([extensionPath], secondCwd);
+		await loadExtensionsCached([extensionPath], secondCwd);
+
+		expect(state().moduleLoads).toBe(2);
+		expect(state().factoryRuns).toBe(3);
+	});
+});

packages/coding-agent/test/suite/regressions/pre-prompt-compaction-no-continue.test.ts

@@ -0,0 +1,75 @@
+import { type AssistantMessage, fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { createHarness, getUserTexts, type Harness } from "../harness.ts";
+
+function createUsage(totalTokens: number) {
+	return {
+		input: totalTokens,
+		output: 0,
+		cacheRead: 0,
+		cacheWrite: 0,
+		totalTokens,
+		cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+	};
+}
+
+describe("pre-prompt compaction regression", () => {
+	const harnesses: Harness[] = [];
+
+	afterEach(() => {
+		vi.restoreAllMocks();
+		while (harnesses.length > 0) {
+			harnesses.pop()?.cleanup();
+		}
+	});
+
+	it("compacts length-stop overflow before a new prompt without continuing from an assistant message", async () => {
+		const harness = await createHarness({
+			models: [{ id: "faux-1", contextWindow: 100, maxTokens: 100 }],
+			settings: { compaction: { enabled: true, keepRecentTokens: 1, reserveTokens: 0 } },
+			extensionFactories: [
+				(pi) => {
+					pi.on("session_before_compact", async (event) => ({
+						compaction: {
+							summary: "pre-prompt summary",
+							firstKeptEntryId: event.preparation.firstKeptEntryId,
+							tokensBefore: event.preparation.tokensBefore,
+							details: {},
+						},
+					}));
+				},
+			],
+		});
+		harnesses.push(harness);
+
+		const now = Date.now();
+		const model = harness.getModel();
+		harness.sessionManager.appendMessage({
+			role: "user",
+			content: [{ type: "text", text: "previous prompt" }],
+			timestamp: now - 1000,
+		});
+		const lengthStopAssistant: AssistantMessage = {
+			...fauxAssistantMessage("length-stop assistant response", { stopReason: "length", timestamp: now - 500 }),
+			api: model.api,
+			provider: model.provider,
+			model: model.id,
+			usage: createUsage(100),
+		};
+		harness.sessionManager.appendMessage(lengthStopAssistant);
+		harness.session.agent.state.messages = harness.sessionManager.buildSessionContext().messages;
+		harness.setResponses([fauxAssistantMessage("answered next prompt")]);
+		const continueSpy = vi.spyOn(harness.session.agent, "continue");
+
+		await expect(harness.session.prompt("next prompt")).resolves.toBeUndefined();
+
+		expect(continueSpy).not.toHaveBeenCalled();
+		expect(harness.eventsOfType("compaction_end").at(-1)).toMatchObject({
+			reason: "overflow",
+			aborted: false,
+			willRetry: true,
+		});
+		expect(getUserTexts(harness)).toContain("next prompt");
+		expect(harness.faux.state.callCount).toBe(1);
+	});
+});

packages/coding-agent/test/suite/regressions/startup-session-rebind-duplicate-subscription.test.ts

@@ -0,0 +1,77 @@
+import { describe, expect, it, vi } from "vitest";
+import { InteractiveMode } from "../../../src/modes/interactive/interactive-mode.ts";
+
+type RebindContext = {
+	session: object;
+	unsubscribe?: () => void;
+	applyRuntimeSettings: () => void;
+	renderCurrentSessionState: () => void;
+	bindCurrentSessionExtensions: () => Promise<void>;
+	subscribeToAgent: () => void;
+	updateAvailableProviderCount: () => Promise<void>;
+	updateEditorBorderColor: () => void;
+	updateTerminalTitle: () => void;
+};
+
+type InteractiveModePrototype = {
+	rebindCurrentSession(this: RebindContext, options?: { renderBeforeBind?: boolean }): Promise<void>;
+};
+
+const interactiveModePrototype = InteractiveMode.prototype as unknown as InteractiveModePrototype;
+
+describe("overlapping startup and replacement session rebinds", () => {
+	it("does not subscribe from the stale startup rebind", async () => {
+		const startupSession = {};
+		const replacementSession = {};
+		let resolveStartupBind!: () => void;
+		let resolveReplacementBind!: () => void;
+
+		const startupBind = new Promise<void>((resolve) => {
+			resolveStartupBind = resolve;
+		});
+		const replacementBind = new Promise<void>((resolve) => {
+			resolveReplacementBind = resolve;
+		});
+
+		const subscribeToAgent = vi.fn();
+		const updateTerminalTitle = vi.fn();
+		let bindCount = 0;
+
+		const context: RebindContext = {
+			session: startupSession,
+			applyRuntimeSettings: () => {},
+			renderCurrentSessionState: () => {},
+			bindCurrentSessionExtensions: () => {
+				bindCount += 1;
+				return bindCount === 1 ? startupBind : replacementBind;
+			},
+			subscribeToAgent,
+			updateAvailableProviderCount: async () => {},
+			updateEditorBorderColor: () => {},
+			updateTerminalTitle,
+		};
+
+		const startupRebind = interactiveModePrototype.rebindCurrentSession.call(context);
+		expect(bindCount).toBe(1);
+
+		context.session = replacementSession;
+		const replacementRebind = interactiveModePrototype.rebindCurrentSession.call(context, {
+			renderBeforeBind: true,
+		});
+
+		expect(bindCount).toBe(2);
+		expect(subscribeToAgent).toHaveBeenCalledTimes(1);
+
+		resolveStartupBind();
+		await startupRebind;
+
+		expect(subscribeToAgent).toHaveBeenCalledTimes(1);
+		expect(updateTerminalTitle).not.toHaveBeenCalled();
+
+		resolveReplacementBind();
+		await replacementRebind;
+
+		expect(subscribeToAgent).toHaveBeenCalledTimes(1);
+		expect(updateTerminalTitle).toHaveBeenCalledTimes(1);
+	});
+});

packages/coding-agent/test/suite/regressions/tree-during-streaming.test.ts

@@ -0,0 +1,35 @@
+import { fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { describe, expect, it } from "vitest";
+import { userMsg } from "../../utilities.ts";
+import { createHarness } from "../harness.ts";
+
+describe("tree navigation during an active response", () => {
+	it("rejects navigation without changing the active leaf", async () => {
+		const harness = await createHarness();
+		const targetId = harness.sessionManager.appendMessage(userMsg("first"));
+		let navigationResult: unknown;
+		let leafUnchanged = false;
+
+		try {
+			// Navigate from inside the response factory, while the run is active.
+			harness.setResponses([
+				async () => {
+					const activeLeafId = harness.sessionManager.getLeafId();
+					navigationResult = await harness.session
+						.navigateTree(targetId, { summarize: false })
+						.catch((error) => error);
+					leafUnchanged = activeLeafId !== targetId && harness.sessionManager.getLeafId() === activeLeafId;
+					return fauxAssistantMessage("response");
+				},
+			]);
+			await harness.session.prompt("second");
+
+			expect(navigationResult).toEqual(
+				new Error("Wait for the current response to finish before navigating the session tree."),
+			);
+			expect(leafUnchanged).toBe(true);
+		} finally {
+			harness.cleanup();
+		}
+	});
+});