Add pi-harness breadcrumbs and vendored session naming

modules/_ai-tools/session-name.ts

@@ -0,0 +1,260 @@
+import type { ExtensionAPI, ExtensionContext } from "@mariozechner/pi-coding-agent";
+import {
+	createAgentSession,
+	DefaultResourceLoader,
+	getAgentDir,
+	SessionManager,
+	SettingsManager,
+} from "@mariozechner/pi-coding-agent";
+
+interface SessionNameState {
+	hasAutoNamed: boolean;
+}
+
+const TITLE_MODEL = {
+	provider: "openai-codex",
+	id: "gpt-5.4-mini",
+} as const;
+
+const MAX_TITLE_LENGTH = 50;
+const MAX_RETRIES = 2;
+const FALLBACK_LENGTH = 50;
+const TITLE_ENTRY_TYPE = "vendored-session-title";
+
+const TITLE_SYSTEM_PROMPT = `You are generating a succinct title for a coding session based on the provided conversation.
+
+Requirements:
+- Maximum 50 characters
+- Sentence case (capitalize only first word and proper nouns)
+- Capture the main intent or task
+- Reuse the user's exact words and technical terms
+- Match the user's language
+- No quotes, colons, or markdown formatting
+- No generic titles like "Coding session" or "Help with code"
+- No explanations or commentary
+
+Output ONLY the title text. Nothing else.`;
+
+function isTurnCompleted(event: unknown): boolean {
+	if (!event || typeof event !== "object") return false;
+	const message = (event as { message?: unknown }).message;
+	if (!message || typeof message !== "object") return false;
+	const stopReason = (message as { stopReason?: unknown }).stopReason;
+	return typeof stopReason === "string" && stopReason.toLowerCase() === "stop";
+}
+
+function buildFallbackTitle(userText: string): string {
+	const text = userText.trim();
+	if (text.length <= FALLBACK_LENGTH) return text;
+	const truncated = text.slice(0, FALLBACK_LENGTH - 3);
+	const lastSpace = truncated.lastIndexOf(" ");
+	return `${lastSpace > 0 ? truncated.slice(0, lastSpace) : truncated}...`;
+}
+
+function postProcessTitle(raw: string): string {
+	let title = raw;
+
+	title = title.replace(/<thinking[\s\S]*?<\/thinking>\s*/g, "");
+	title = title.replace(/^["'`]+|["'`]+$/g, "");
+	title = title.replace(/^#+\s*/, "");
+	title = title.replace(/\*{1,2}(.*?)\*{1,2}/g, "$1");
+	title = title.replace(/_{1,2}(.*?)_{1,2}/g, "$1");
+	title = title.replace(/^(Title|Summary|Session)\s*:\s*/i, "");
+	title =
+		title
+			.split("\n")
+			.map((line) => line.trim())
+			.find((line) => line.length > 0) ?? title;
+	title = title.trim();
+
+	if (title.length > MAX_TITLE_LENGTH) {
+		const truncated = title.slice(0, MAX_TITLE_LENGTH - 3);
+		const lastSpace = truncated.lastIndexOf(" ");
+		title = `${lastSpace > 0 ? truncated.slice(0, lastSpace) : truncated}...`;
+	}
+
+	return title;
+}
+
+function getLatestUserText(ctx: ExtensionContext): string | null {
+	const entries = ctx.sessionManager.getEntries();
+	for (let i = entries.length - 1; i >= 0; i -= 1) {
+		const entry = entries[i];
+		if (!entry || entry.type !== "message") continue;
+		if (entry.message.role !== "user") continue;
+
+		const { content } = entry.message as { content: unknown };
+		if (typeof content === "string") return content;
+		if (!Array.isArray(content)) return null;
+
+		return content
+			.filter(
+				(part): part is { type: string; text?: string } =>
+					typeof part === "object" && part !== null && "type" in part,
+			)
+			.filter((part) => part.type === "text" && typeof part.text === "string")
+			.map((part) => part.text ?? "")
+			.join(" ");
+	}
+
+	return null;
+}
+
+function getLatestAssistantText(ctx: ExtensionContext): string | null {
+	const entries = ctx.sessionManager.getEntries();
+	for (let i = entries.length - 1; i >= 0; i -= 1) {
+		const entry = entries[i];
+		if (!entry || entry.type !== "message") continue;
+		if (entry.message.role !== "assistant") continue;
+
+		const { content } = entry.message as { content: unknown };
+		if (typeof content === "string") return content;
+		if (!Array.isArray(content)) return null;
+
+		return content
+			.filter(
+				(part): part is { type: string; text?: string } =>
+					typeof part === "object" && part !== null && "type" in part,
+			)
+			.filter((part) => part.type === "text" && typeof part.text === "string")
+			.map((part) => part.text ?? "")
+			.join("\n");
+	}
+
+	return null;
+}
+
+function resolveModel(ctx: ExtensionContext) {
+	const available = ctx.modelRegistry.getAvailable();
+	const model = available.find(
+		(candidate) => candidate.provider === TITLE_MODEL.provider && candidate.id === TITLE_MODEL.id,
+	);
+	if (model) return model;
+
+	const existsWithoutKey = ctx.modelRegistry
+		.getAll()
+		.some((candidate) => candidate.provider === TITLE_MODEL.provider && candidate.id === TITLE_MODEL.id);
+	if (existsWithoutKey) {
+		throw new Error(
+			`Model ${TITLE_MODEL.provider}/${TITLE_MODEL.id} exists but has no configured API key.`,
+		);
+	}
+
+	throw new Error(`Model ${TITLE_MODEL.provider}/${TITLE_MODEL.id} is not available.`);
+}
+
+async function generateTitle(userText: string, assistantText: string, ctx: ExtensionContext): Promise<string> {
+	const agentDir = getAgentDir();
+	const settingsManager = SettingsManager.create(ctx.cwd, agentDir);
+	const resourceLoader = new DefaultResourceLoader({
+		cwd: ctx.cwd,
+		agentDir,
+		settingsManager,
+		noExtensions: true,
+		noPromptTemplates: true,
+		noThemes: true,
+		noSkills: true,
+		systemPromptOverride: () => TITLE_SYSTEM_PROMPT,
+		appendSystemPromptOverride: () => [],
+		agentsFilesOverride: () => ({ agentsFiles: [] }),
+	});
+	await resourceLoader.reload();
+
+	const { session } = await createAgentSession({
+		model: resolveModel(ctx),
+		thinkingLevel: "off",
+		sessionManager: SessionManager.inMemory(),
+		modelRegistry: ctx.modelRegistry,
+		resourceLoader,
+	});
+
+	let accumulated = "";
+	const unsubscribe = session.subscribe((event) => {
+		if (event.type === "message_update" && event.assistantMessageEvent.type === "text_delta") {
+			accumulated += event.assistantMessageEvent.delta;
+		}
+	});
+
+	const description = assistantText
+		? `<user>${userText}</user>\n<assistant>${assistantText}</assistant>`
+		: `<user>${userText}</user>`;
+	const userMessage = `<conversation>\n${description}\n</conversation>\n\nGenerate a title:`;
+
+	try {
+		await session.prompt(userMessage);
+	} finally {
+		unsubscribe();
+		session.dispose();
+	}
+
+	return postProcessTitle(accumulated);
+}
+
+async function generateAndSetTitle(pi: ExtensionAPI, ctx: ExtensionContext): Promise<void> {
+	const userText = getLatestUserText(ctx);
+	if (!userText?.trim()) return;
+
+	const assistantText = getLatestAssistantText(ctx) ?? "";
+	if (!assistantText.trim()) return;
+
+	let lastError: Error | null = null;
+	for (let attempt = 1; attempt <= MAX_RETRIES; attempt += 1) {
+		try {
+			const title = await generateTitle(userText, assistantText, ctx);
+			if (!title) continue;
+
+			pi.setSessionName(title);
+			pi.appendEntry(TITLE_ENTRY_TYPE, {
+				title,
+				rawUserText: userText,
+				rawAssistantText: assistantText,
+				attempt,
+				model: `${TITLE_MODEL.provider}/${TITLE_MODEL.id}`,
+			});
+			ctx.ui.notify(`Session: ${title}`, "info");
+			return;
+		} catch (error) {
+			lastError = error instanceof Error ? error : new Error(String(error));
+		}
+	}
+
+	const fallback = buildFallbackTitle(userText);
+	pi.setSessionName(fallback);
+	pi.appendEntry(TITLE_ENTRY_TYPE, {
+		title: fallback,
+		fallback: true,
+		error: lastError?.message ?? "Unknown error",
+		rawUserText: userText,
+		rawAssistantText: assistantText,
+		model: `${TITLE_MODEL.provider}/${TITLE_MODEL.id}`,
+	});
+	ctx.ui.notify(`Title generation failed, using fallback: ${fallback}`, "warning");
+}
+
+export default function setupSessionNameHook(pi: ExtensionAPI) {
+	const state: SessionNameState = {
+		hasAutoNamed: false,
+	};
+
+	pi.on("session_start", async () => {
+		state.hasAutoNamed = false;
+	});
+
+	pi.on("session_switch", async () => {
+		state.hasAutoNamed = false;
+	});
+
+	pi.on("turn_end", async (event, ctx) => {
+		if (state.hasAutoNamed) return;
+
+		if (pi.getSessionName()) {
+			state.hasAutoNamed = true;
+			return;
+		}
+
+		if (!isTurnCompleted(event)) return;
+
+		await generateAndSetTitle(pi, ctx);
+		state.hasAutoNamed = true;
+	});
+}

modules/ai-tools.nix

@@ -23,6 +23,7 @@
 			".pi/agent/extensions/no-git.ts".source = ./_ai-tools/no-git.ts;
 			".pi/agent/extensions/no-scripting.ts".source = ./_ai-tools/no-scripting.ts;
 			".pi/agent/extensions/review.ts".source = ./_ai-tools/review.ts;
+			".pi/agent/extensions/session-name.ts".source = ./_ai-tools/session-name.ts;
 			".pi/agent/skills/elixir-dev" = {
 				source = "${inputs.pi-elixir}/skills/elixir-dev";
 				recursive = true;
@@ -51,6 +52,13 @@
 							prompts = [];
 							themes = [];
 						}
+						{
+							source = "${inputs.pi-harness}";
+							extensions = ["extensions/breadcrumbs/index.ts"];
+							skills = [];
+							prompts = [];
+							themes = [];
+						}
 					];
 				};
 			".pi/agent/mcp.json".text =

modules/dendritic.nix

@@ -66,6 +66,10 @@
 			url = "github:zenobi-us/pi-rose-pine";
 			flake = false;
 		};
+		pi-harness = {
+			url = "github:aliou/pi-harness";
+			flake = false;
+		};
 		# Overlay inputs
 		himalaya.url = "github:pimalaya/himalaya";
 		jj-ryu = {