up

flake.lock

@@ -848,6 +848,22 @@
         "type": "github"
       }
     },
+    "pi-harness": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1774210293,
+        "narHash": "sha256-YzQn5r5KAORu6FI7dIkKWTU5f/HYinYu7i8QwPKCYik=",
+        "owner": "aliou",
+        "repo": "pi-harness",
+        "rev": "720db4f57cafd732953fae14ecb5eb50ff4d808c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "aliou",
+        "repo": "pi-harness",
+        "type": "github"
+      }
+    },
     "pi-rose-pine": {
       "flake": false,
       "locked": {
@@ -911,6 +927,7 @@
         "nixvim": "nixvim",
         "pi-agent-stuff": "pi-agent-stuff",
         "pi-elixir": "pi-elixir",
+        "pi-harness": "pi-harness",
         "pi-rose-pine": "pi-rose-pine",
         "sops-nix": "sops-nix",
         "zjstatus": "zjstatus"

flake.nix

@@ -76,6 +76,10 @@
 			url = "github:dannote/pi-elixir";
 			flake = false;
 		};
+		pi-harness = {
+			url = "github:aliou/pi-harness";
+			flake = false;
+		};
 		pi-rose-pine = {
 			url = "github:zenobi-us/pi-rose-pine";
 			flake = false;

modules/_ai-tools/no-git.ts

@@ -0,0 +1,190 @@
+/**
+ * No Git Extension
+ *
+ * Blocks direct git invocations and tells the LLM to use jj (Jujutsu) instead.
+ * Mentions of the word "git" in search patterns, strings, comments, etc. are allowed.
+ */
+
+import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
+import { isToolCallEventType } from "@mariozechner/pi-coding-agent";
+
+type ShellToken =
+	| { type: "word"; value: string }
+	| { type: "operator"; value: string };
+
+const COMMAND_PREFIXES = new Set(["env", "command", "builtin", "time", "sudo", "nohup", "nice"]);
+const SHELL_KEYWORDS = new Set(["if", "then", "elif", "else", "do", "while", "until", "case", "in"]);
+const SHELL_INTERPRETERS = new Set(["bash", "sh", "zsh", "fish", "nu"]);
+
+function isAssignmentWord(value: string): boolean {
+	return /^[A-Za-z_][A-Za-z0-9_]*=.*/.test(value);
+}
+
+function tokenizeShell(command: string): ShellToken[] {
+	const tokens: ShellToken[] = [];
+	let current = "";
+	let quote: "'" | '"' | null = null;
+
+	const pushWord = () => {
+		if (!current) return;
+		tokens.push({ type: "word", value: current });
+		current = "";
+	};
+
+	for (let i = 0; i < command.length; i++) {
+		const char = command[i];
+
+		if (quote) {
+			if (quote === "'") {
+				if (char === "'") {
+					quote = null;
+				} else {
+					current += char;
+				}
+				continue;
+			}
+
+			if (char === '"') {
+				quote = null;
+				continue;
+			}
+
+			if (char === "\\") {
+				if (i + 1 < command.length) {
+					current += command[i + 1];
+					i += 1;
+				}
+				continue;
+			}
+
+			current += char;
+			continue;
+		}
+
+		if (char === "'" || char === '"') {
+			quote = char;
+			continue;
+		}
+
+		if (char === "\\") {
+			if (i + 1 < command.length) {
+				current += command[i + 1];
+				i += 1;
+			}
+			continue;
+		}
+
+		if (/\s/.test(char)) {
+			pushWord();
+			if (char === "\n") {
+				tokens.push({ type: "operator", value: "\n" });
+			}
+			continue;
+		}
+
+		const twoCharOperator = command.slice(i, i + 2);
+		if (twoCharOperator === "&&" || twoCharOperator === "||") {
+			pushWord();
+			tokens.push({ type: "operator", value: twoCharOperator });
+			i += 1;
+			continue;
+		}
+
+		if (char === ";" || char === "|" || char === "(" || char === ")") {
+			pushWord();
+			tokens.push({ type: "operator", value: char });
+			continue;
+		}
+
+		current += char;
+	}
+
+	pushWord();
+	return tokens;
+}
+
+function findCommandWord(words: string[]): { word?: string; index: number } {
+	for (let i = 0; i < words.length; i++) {
+		const word = words[i];
+		if (SHELL_KEYWORDS.has(word)) {
+			continue;
+		}
+		if (isAssignmentWord(word)) {
+			continue;
+		}
+		if (COMMAND_PREFIXES.has(word)) {
+			continue;
+		}
+
+		return { word, index: i };
+	}
+
+	return { index: words.length };
+}
+
+function getInlineShellCommand(words: string[], commandIndex: number): string | null {
+	for (let i = commandIndex + 1; i < words.length; i++) {
+		const word = words[i];
+		if (/^(?:-[A-Za-z]*c[A-Za-z]*|--command)$/.test(word)) {
+			return words[i + 1] ?? null;
+		}
+	}
+
+	return null;
+}
+
+function segmentContainsBlockedGit(words: string[]): boolean {
+	const { word, index } = findCommandWord(words);
+	if (!word) {
+		return false;
+	}
+
+	if (word === "git") {
+		return true;
+	}
+
+	if (word === "jj") {
+		return false;
+	}
+
+	if (SHELL_INTERPRETERS.has(word)) {
+		const inlineCommand = getInlineShellCommand(words, index);
+		return inlineCommand ? containsBlockedGitInvocation(inlineCommand) : false;
+	}
+
+	return false;
+}
+
+function containsBlockedGitInvocation(command: string): boolean {
+	const tokens = tokenizeShell(command);
+	let words: string[] = [];
+
+	for (const token of tokens) {
+		if (token.type === "operator") {
+			if (segmentContainsBlockedGit(words)) {
+				return true;
+			}
+			words = [];
+			continue;
+		}
+
+		words.push(token.value);
+	}
+
+	return segmentContainsBlockedGit(words);
+}
+
+export default function (pi: ExtensionAPI) {
+	pi.on("tool_call", async (event, _ctx) => {
+		if (!isToolCallEventType("bash", event)) return;
+
+		const command = event.input.command.trim();
+
+		if (containsBlockedGitInvocation(command)) {
+			return {
+				block: true,
+				reason: "git is not used in this project. Use jj (Jujutsu) instead.",
+			};
+		}
+	});
+}

modules/_ai-tools/no-scripting.ts

@@ -0,0 +1,28 @@
+/**
+ * No Scripting Extension
+ *
+ * Blocks python, perl, ruby, php, lua, and inline bash/sh scripts.
+ * Tells the LLM to use `nu -c` instead.
+ */
+
+import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
+import { isToolCallEventType } from "@mariozechner/pi-coding-agent";
+
+const SCRIPTING_PATTERN =
+	/(?:^|[;&|]\s*|&&\s*|\|\|\s*|\$\(\s*|`\s*)(?:python[23]?|perl|ruby|php|lua|bash\s+-c|sh\s+-c)\s/;
+
+export default function (pi: ExtensionAPI) {
+	pi.on("tool_call", async (event, _ctx) => {
+		if (!isToolCallEventType("bash", event)) return;
+
+		const command = event.input.command.trim();
+
+		if (SCRIPTING_PATTERN.test(command)) {
+			return {
+				block: true,
+				reason:
+					"Do not use python, perl, ruby, php, lua, or inline bash/sh for scripting. Use `nu -c` instead.",
+			};
+		}
+	});
+}

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/_overlays/ast-grep.nix

@@ -0,0 +1,6 @@
+{inputs, ...}: final: prev: {
+	ast-grep =
+		prev.ast-grep.overrideAttrs (old: {
+				doCheck = false;
+			});
+}

modules/_overlays/cog-cli.nix

@@ -0,0 +1,44 @@
+{inputs, ...}: final: prev: let
+	version = "0.22.1";
+	srcs = {
+		x86_64-linux =
+			prev.fetchurl {
+				url = "https://github.com/trycog/cog-cli/releases/download/v${version}/cog-linux-x86_64.tar.gz";
+				hash = "sha256-ET+sNXisUrHShR1gxqdumegXycXcxGzJcQOdTr5005w=";
+			};
+		aarch64-darwin =
+			prev.fetchurl {
+				url = "https://github.com/trycog/cog-cli/releases/download/v${version}/cog-darwin-arm64.tar.gz";
+				hash = "sha256-jcN+DtOqr3or5C71jp7AIAz0wh73FYybCC4FRBykKO4=";
+			};
+	};
+in {
+	cog-cli =
+		prev.stdenvNoCC.mkDerivation {
+			pname = "cog-cli";
+			inherit version;
+			src =
+				srcs.${prev.stdenv.hostPlatform.system}
+				or (throw "Unsupported system for cog-cli: ${prev.stdenv.hostPlatform.system}");
+
+			dontUnpack = true;
+			dontConfigure = true;
+			dontBuild = true;
+
+			installPhase = ''
+				runHook preInstall
+				tar -xzf "$src"
+				install -Dm755 cog "$out/bin/cog"
+				runHook postInstall
+			'';
+
+			meta = with prev.lib; {
+				description = "Memory, code intelligence, and debugging for AI agents";
+				homepage = "https://github.com/trycog/cog-cli";
+				license = licenses.mit;
+				mainProgram = "cog";
+				platforms = builtins.attrNames srcs;
+				sourceProvenance = [sourceTypes.binaryNativeCode];
+			};
+		};
+}

modules/_overlays/himalaya.nix

@@ -0,0 +1,3 @@
+{inputs, ...}: final: prev: {
+	himalaya = inputs.himalaya.packages.${prev.stdenv.hostPlatform.system}.default;
+}

modules/_overlays/jj-ryu.nix

@@ -0,0 +1,15 @@
+{inputs, ...}: final: prev: let
+	naersk-lib = prev.callPackage inputs.naersk {};
+	manifest = (prev.lib.importTOML "${inputs.jj-ryu}/Cargo.toml").package;
+in {
+	jj-ryu =
+		naersk-lib.buildPackage {
+			pname = manifest.name;
+			version = manifest.version;
+			src = inputs.jj-ryu;
+			nativeBuildInputs = [prev.pkg-config];
+			buildInputs = [prev.openssl];
+			OPENSSL_NO_VENDOR = 1;
+			doCheck = false;
+		};
+}

modules/_overlays/jj-starship.nix

@@ -0,0 +1 @@
+{inputs, ...}: inputs.jj-starship.overlays.default

modules/_overlays/pi-agent-stuff.nix

@@ -0,0 +1,10 @@
+{inputs, ...}: final: prev: {
+	pi-agent-stuff =
+		prev.buildNpmPackage {
+			pname = "pi-agent-stuff";
+			version = "1.5.0";
+			src = inputs.pi-agent-stuff;
+			npmDepsHash = "sha256-pyXMNdlie8vAkhz2f3GUGT3CCYuwt+xkWnsijBajXIo=";
+			dontNpmBuild = true;
+		};
+}

modules/_overlays/pi-harness.nix

@@ -0,0 +1,33 @@
+{inputs, ...}: final: prev: {
+	pi-harness =
+		prev.stdenvNoCC.mkDerivation {
+			pname = "pi-harness";
+			version = "0.0.0";
+			src = inputs.pi-harness;
+
+			pnpmDeps =
+				prev.fetchPnpmDeps {
+					pname = "pi-harness";
+					version = "0.0.0";
+					src = inputs.pi-harness;
+					pnpm = prev.pnpm_10;
+					fetcherVersion = 1;
+					hash = "sha256-FgtJnmJ0/udz2A9N2DQns+a2CspMDEDk0DPUAxmCVY4=";
+				};
+
+			nativeBuildInputs = [
+				prev.pnpmConfigHook
+				prev.pnpm_10
+				prev.nodejs
+			];
+
+			dontBuild = true;
+
+			installPhase = ''
+				runHook preInstall
+				mkdir -p $out/lib/node_modules/@aliou/pi-harness
+				cp -r . $out/lib/node_modules/@aliou/pi-harness
+				runHook postInstall
+			'';
+		};
+}

modules/_overlays/pi-mcp-adapter.nix

@@ -0,0 +1,16 @@
+{inputs, ...}: final: prev: {
+	pi-mcp-adapter =
+		prev.buildNpmPackage {
+			pname = "pi-mcp-adapter";
+			version = "2.2.0";
+			src =
+				prev.fetchFromGitHub {
+					owner = "nicobailon";
+					repo = "pi-mcp-adapter";
+					rev = "v2.2.0";
+					hash = "sha256-E6Kf+OyTN/pF8pKADJO0B1+buAPqNcXnZl9ssZwSP8U=";
+				};
+			npmDepsHash = "sha256-myJ9h/zC/KDddt8NOVvJjjqbnkdEN4ZR+okCR5nu7hM=";
+			dontNpmBuild = true;
+		};
+}

modules/_overlays/zjstatus.nix

@@ -0,0 +1,3 @@
+{inputs, ...}: final: prev: {
+	zjstatus = inputs.zjstatus.packages.${prev.stdenv.hostPlatform.system}.default;
+}

modules/ai-tools.nix

@@ -2,6 +2,7 @@
 	den.aspects.ai-tools.homeManager = {
 		pkgs,
 		inputs',
+		lib,
 		...
 	}: {
 		home.packages = [
@@ -20,77 +21,171 @@
 				source = "${pkgs.pi-mcp-adapter}/lib/node_modules/pi-mcp-adapter";
 				recursive = true;
 			};
+			".pi/agent/extensions/no-git.ts".source = ./_ai-tools/no-git.ts;
+			".pi/agent/extensions/no-scripting.ts".source = ./_ai-tools/no-scripting.ts;
 			".pi/agent/extensions/review.ts".source = ./_ai-tools/review.ts;
+			".pi/agent/extensions/session-name.ts".source = ./_ai-tools/session-name.ts;
 			".pi/agent/skills/elixir-dev" = {
 				source = "${inputs.pi-elixir}/skills/elixir-dev";
 				recursive = true;
 			};
+			".pi/agent/skills/jujutsu/SKILL.md".text =
+				lib.removePrefix "\n" (builtins.replaceStrings ["\t"] [""] ''
+						---
+						name: jujutsu
+						description: Manages version control with Jujutsu (jj), including rebasing, conflict resolution, and Git interop. Use when tracking changes, navigating history, squashing/splitting commits, or pushing to Git remotes.
+						---
+
+						# Jujutsu
+
+						Git-compatible VCS focused on concurrent development and ease of use.
+
+						> ⚠️ **Not Git!** Jujutsu syntax differs from Git:
+						>
+						> - Parent: `@-` not `@~1` or `@^`
+						> - Grandparent: `@--` not `@~2`
+						> - Child: `@+` not `@~-1`
+						> - Use `jj log` not `jj changes`
+
+						## Key Commands
+
+						| Command                    | Description                                  |
+						| -------------------------- | -------------------------------------------- |
+						| `jj st`                    | Show working copy status                     |
+						| `jj log`                   | Show change log                              |
+						| `jj diff`                  | Show changes in working copy                 |
+						| `jj new`                   | Create new change                            |
+						| `jj desc`                  | Edit change description                      |
+						| `jj squash`                | Move changes to parent                       |
+						| `jj split`                 | Split current change                         |
+						| `jj rebase -s src -d dest` | Rebase changes                               |
+						| `jj absorb`                | Move changes into stack of mutable revisions |
+						| `jj bisect`                | Find bad revision by bisection               |
+						| `jj fix`                   | Update files with formatting fixes           |
+						| `jj sign`                  | Cryptographically sign a revision            |
+						| `jj metaedit`              | Modify metadata without changing content     |
+
+						## Basic Workflow
+
+						```bash
+						jj new                   # Create new change
+						jj desc -m "feat: add feature"  # Set description
+						jj log                   # View history
+						jj edit change-id        # Switch to change
+						jj new --before @        # Time travel (create before current)
+						jj edit @-               # Go to parent
+						```
+
+						## Time Travel
+
+						```bash
+						jj edit change-id        # Switch to specific change
+						jj next --edit           # Next child change
+						jj edit @-               # Parent change
+						jj new --before @ -m msg # Insert before current
+						```
+
+						## Merging & Rebasing
+
+						```bash
+						jj new x yz -m msg       # Merge changes
+						jj rebase -s src -d dest # Rebase source onto dest
+						jj abandon              # Delete current change
+						```
+
+						## Conflicts
+
+						```bash
+						jj resolve              # Interactive conflict resolution
+						# Edit files, then continue
+						```
+
+						## Revset Syntax
+
+						**Parent/child operators:**
+
+						| Syntax | Meaning          | Example              |
+						| ------ | ---------------- | -------------------- |
+						| `@-`   | Parent of @      | `jj diff -r @-`      |
+						| `@--`  | Grandparent      | `jj log -r @--`      |
+						| `x-`   | Parent of x      | `jj diff -r abc123-` |
+						| `@+`   | Child of @       | `jj log -r @+`       |
+						| `x::y` | x to y inclusive | `jj log -r main::@`  |
+						| `x..y` | x to y exclusive | `jj log -r main..@`  |
+						| `x\|y` | Union (or)       | `jj log -r 'a \| b'` |
+
+						**⚠️ Common mistakes:**
+
+						- ❌ `@~1` → ✅ `@-` (parent)
+						- ❌ `@^` → ✅ `@-` (parent)
+						- ❌ `@~-1` → ✅ `@+` (child)
+						- ❌ `jj changes` → ✅ `jj log` or `jj diff`
+						- ❌ `a,b,c` → ✅ `a | b | c` (union uses pipe, not comma)
+
+						**Functions:**
+
+						```bash
+						jj log -r 'heads(all())'        # All heads
+						jj log -r 'remote_bookmarks()..'  # Not on remote
+						jj log -r 'author(name)'        # By author
+						jj log -r 'description(regex)'  # By description
+						jj log -r 'mine()'              # My commits
+						jj log -r 'committer_date(after:"7 days ago")'  # Recent commits
+						jj log -r 'mine() & committer_date(after:"yesterday")'  # My recent
+						```
+
+						## Templates
+
+						```bash
+						jj log -T 'commit_id ++ "\n" ++ description'
+						```
+
+						## Git Interop
+
+						```bash
+						jj bookmark create main -r @  # Create bookmark
+						jj git push --bookmark main   # Push bookmark
+						jj git fetch                 # Fetch from remote
+						jj bookmark track main@origin # Track remote
+						```
+
+						## Advanced Commands
+
+						```bash
+						jj absorb               # Auto-move changes to relevant commits in stack
+						jj bisect start         # Start bisection
+						jj bisect good          # Mark current as good
+						jj bisect bad           # Mark current as bad
+						jj fix                  # Run configured formatters on files
+						jj sign -r @            # Sign current revision
+						jj metaedit -r @ -m "new message"  # Edit metadata only
+						```
+
+						## Tips
+
+						- No staging: changes are immediate
+						- Use conventional commits: `type(scope): desc`
+						- `jj undo` to revert operations
+						- `jj op log` to see operation history
+						- Bookmarks are like branches
+						- `jj absorb` is powerful for fixing up commits in a stack
+
+						## Related Skills
+
+						- **gh**: GitHub CLI for PRs and issues
+						- **review**: Code review before committing
+					'');
 			".pi/agent/themes" = {
 				source = "${inputs.pi-rose-pine}/themes";
 				recursive = true;
 			};
-			".pi/agent/extensions/no-git.ts".text = ''
-				/**
-				 * No Git Extension
-				 *
-				 * Blocks git commands and tells the LLM to use jj (Jujutsu) instead.
-				 */
-
-				import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
-				import { isToolCallEventType } from "@mariozechner/pi-coding-agent";
-
-				export default function (pi: ExtensionAPI) {
-					pi.on("tool_call", async (event, _ctx) => {
-						if (!isToolCallEventType("bash", event)) return;
-
-						const command = event.input.command.trim();
-
-						if (/\bgit\b/.test(command) && !/\bjj\s+git\b/.test(command)) {
-							return {
-								block: true,
-								reason: "git is not used in this project. Use jj (Jujutsu) instead.",
-							};
-						}
-					});
-				}
-			'';
-			".pi/agent/extensions/no-scripting.ts".text = ''
-				/**
-				 * No Scripting Extension
-				 *
-				 * Blocks python, perl, ruby, php, lua, and inline bash/sh scripts.
-				 * Tells the LLM to use `nu -c` instead.
-				 */
-
-				import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
-				import { isToolCallEventType } from "@mariozechner/pi-coding-agent";
-
-				const SCRIPTING_PATTERN =
-					/(?:^|[;&|]\s*|&&\s*|\|\|\s*|\$\(\s*|`\s*)(?:python[23]?|perl|ruby|php|lua|bash\s+-c|sh\s+-c)\s/;
-
-				export default function (pi: ExtensionAPI) {
-					pi.on("tool_call", async (event, _ctx) => {
-						if (!isToolCallEventType("bash", event)) return;
-
-						const command = event.input.command.trim();
-
-						if (SCRIPTING_PATTERN.test(command)) {
-							return {
-								block: true,
-								reason:
-									"Do not use python, perl, ruby, php, lua, or inline bash/sh for scripting. Use `nu -c` instead.",
-							};
-						}
-					});
-				}
-			'';
 			".pi/agent/settings.json".text =
 				builtins.toJSON {
-					lastChangelogVersion = "0.61.1";
 					theme = "rose-pine-dawn";
+					quietStartup = true;
 					hideThinkingBlock = true;
-					defaultProvider = "anthropic";
+					defaultProvider = "openai-codex";
-					defaultModel = "claude-opus-4-6";
+					defaultModel = "gpt-5.4";
 					defaultThinkingLevel = "high";
 					packages = [
 						{
@@ -105,6 +200,13 @@
 							prompts = [];
 							themes = [];
 						}
+						{
+							source = "${pkgs.pi-harness}/lib/node_modules/@aliou/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 = {

modules/overlays.nix

@@ -1,112 +1,23 @@
 {inputs, ...}: let
 	overlays = [
 		# himalaya
-		(final: prev: {
+		(import ./_overlays/himalaya.nix {inherit inputs;})
-				himalaya = inputs.himalaya.packages.${prev.stdenv.hostPlatform.system}.default;
-			})
 		# ast-grep (test_scan_invalid_rule_id fails on darwin in sandbox)
-		(final: prev: {
+		(import ./_overlays/ast-grep.nix {inherit inputs;})
-				ast-grep =
-					prev.ast-grep.overrideAttrs (old: {
-							doCheck = false;
-						});
-			})
 		# jj-ryu
-		(final: prev: let
+		(import ./_overlays/jj-ryu.nix {inherit inputs;})
-				naersk-lib = prev.callPackage inputs.naersk {};
-				manifest = (prev.lib.importTOML "${inputs.jj-ryu}/Cargo.toml").package;
-			in {
-				jj-ryu =
-					naersk-lib.buildPackage {
-						pname = manifest.name;
-						version = manifest.version;
-						src = inputs.jj-ryu;
-						nativeBuildInputs = [prev.pkg-config];
-						buildInputs = [prev.openssl];
-						OPENSSL_NO_VENDOR = 1;
-						doCheck = false;
-					};
-			})
-
 		# cog-cli
-		(final: prev: let
+		(import ./_overlays/cog-cli.nix {inherit inputs;})
-				version = "0.22.0";
-				srcs = {
-					x86_64-linux =
-						prev.fetchurl {
-							url = "https://github.com/trycog/cog-cli/releases/download/v${version}/cog-linux-x86_64.tar.gz";
-							hash = "sha256-GKCO8kUUPl1OQSVhefRy3CIitdkm//nI7LKifyOx+lk=";
-						};
-					aarch64-darwin =
-						prev.fetchurl {
-							url = "https://github.com/trycog/cog-cli/releases/download/v${version}/cog-darwin-arm64.tar.gz";
-							hash = "sha256-uFkOoy2uFtRvuS7Cqb7ivKdvuDzV9ERNgMq2wiOHI7k=";
-						};
-				};
-			in {
-				cog-cli =
-					prev.stdenvNoCC.mkDerivation {
-						pname = "cog-cli";
-						inherit version;
-						src =
-							srcs.${prev.stdenv.hostPlatform.system}
-						or (throw "Unsupported system for cog-cli: ${prev.stdenv.hostPlatform.system}");
-
-						dontUnpack = true;
-						dontConfigure = true;
-						dontBuild = true;
-
-						installPhase = ''
-							runHook preInstall
-							tar -xzf "$src"
-							install -Dm755 cog "$out/bin/cog"
-							runHook postInstall
-						'';
-
-						meta = with prev.lib; {
-							description = "Memory, code intelligence, and debugging for AI agents";
-							homepage = "https://github.com/trycog/cog-cli";
-							license = licenses.mit;
-							mainProgram = "cog";
-							platforms = builtins.attrNames srcs;
-							sourceProvenance = [sourceTypes.binaryNativeCode];
-						};
-					};
-			})
 		# pi-agent-stuff (mitsuhiko)
-		(final: prev: {
+		(import ./_overlays/pi-agent-stuff.nix {inherit inputs;})
-				pi-agent-stuff =
+		# pi-harness (aliou)
-					prev.buildNpmPackage {
+		(import ./_overlays/pi-harness.nix {inherit inputs;})
-						pname = "pi-agent-stuff";
-						version = "1.5.0";
-						src = inputs.pi-agent-stuff;
-						npmDepsHash = "sha256-pyXMNdlie8vAkhz2f3GUGT3CCYuwt+xkWnsijBajXIo=";
-						dontNpmBuild = true;
-					};
-			})
 		# pi-mcp-adapter
-		(final: prev: {
+		(import ./_overlays/pi-mcp-adapter.nix {inherit inputs;})
-				pi-mcp-adapter =
-					prev.buildNpmPackage {
-						pname = "pi-mcp-adapter";
-						version = "2.2.0";
-						src =
-							prev.fetchFromGitHub {
-								owner = "nicobailon";
-								repo = "pi-mcp-adapter";
-								rev = "v2.2.0";
-								hash = "sha256-E6Kf+OyTN/pF8pKADJO0B1+buAPqNcXnZl9ssZwSP8U=";
-							};
-						npmDepsHash = "sha256-myJ9h/zC/KDddt8NOVvJjjqbnkdEN4ZR+okCR5nu7hM=";
-						dontNpmBuild = true;
-					};
-			})
 		# jj-starship (passes through upstream overlay)
-		inputs.jj-starship.overlays.default
+		(import ./_overlays/jj-starship.nix {inherit inputs;})
 		# zjstatus
-		(final: prev: {
+		(import ./_overlays/zjstatus.nix {inherit inputs;})
-				zjstatus = inputs.zjstatus.packages.${prev.stdenv.hostPlatform.system}.default;
-			})
 	];
 in {
 	den.default.nixos.nixpkgs.overlays = overlays;