oh-my-pi/AGENTS.md

Development Rules

First Message

If the user did not give you a concrete task in their first message, read README.md, then ask which module(s) to work on. Based on the answer, read the relevant README.md files in parallel.

• packages/ai/README.md
• packages/tui/README.md
• packages/agent/README.md
• packages/coding-agent/README.md
• packages/mom/README.md
• packages/web-ui/README.md

Code Quality

• No any types unless absolutely necessary
• Check node_modules for external API type definitions instead of guessing
• NEVER use inline imports - no await import("./foo.js"), no import("pkg").Type in type positions, no dynamic imports for types. Always use standard top-level imports.
• NEVER remove or downgrade code to fix type errors from outdated dependencies; upgrade the dependency instead
• Always ask before removing functionality or code that appears to be intentional

Bun Over Node

This project uses Bun as its runtime. Always prefer Bun APIs over Node.js equivalents.

Process Spawning

// GOOD: Bun.spawn with ReadableStream API
import type { Subprocess } from "bun";

const child: Subprocess = Bun.spawn(["cmd", ...args], {
   stdin: "ignore",
   stdout: "pipe",
   stderr: "pipe",
});

const reader = (child.stdout as ReadableStream<Uint8Array>).getReader();
while (true) {
   const { done, value } = await reader.read();
   if (done) break;
   // process Buffer.from(value)
}
const exitCode = await child.exited;

// BAD: Node child_process
import { spawn } from "node:child_process";
const child = spawn("cmd", args);
child.stdout.on("data", (chunk) => { ... });
child.on("close", (code) => { ... });

Sync Process Execution

// GOOD: Bun.spawnSync
const result = Bun.spawnSync(["cmd", ...args], {
   stdin: "ignore",
   stdout: "pipe",
   stderr: "pipe",
});
if (result.exitCode === 0) { ... }

// BAD: Node execSync/spawnSync
import { spawnSync } from "node:child_process";

File I/O

// GOOD: Bun.file and Bun.write
const content = await Bun.file("path.txt").text();
const binary = await Bun.file("image.png").arrayBuffer();
const exists = await Bun.file("maybe.txt").exists();
await Bun.write("path.txt", content);

// BAD: Node fs
import { readFileSync, writeFileSync, existsSync } from "node:fs";

Scripts and package.json

// GOOD: Use bun in scripts
{
   "scripts": {
      "start": "bun run src/index.ts",
      "test": "bun test",
      "check": "bunx tsc --noEmit"
   }
}

// BAD: Use node/npm/npx
{
   "scripts": {
      "start": "node dist/index.js",
      "test": "npm test",
      "check": "npx tsc --noEmit"
   }
}

Running Commands

# GOOD
bun run script.ts
bun test
bunx tsc --noEmit
bun install

# BAD
node script.js
npm test
npx tsc --noEmit
npm install

Type Imports for Bun APIs

// Import Bun types when needed
import type { Subprocess } from "bun";

// Bun globals are available without import
Bun.spawn(...)
Bun.file(...)
Bun.write(...)
Bun.stdin.stream()

Casting Bun Subprocess Streams

Bun's Subprocess.stdout/stderr types can be number | ReadableStream | undefined. Cast when using pipe mode:

const child = Bun.spawn(["cmd"], { stdout: "pipe", stderr: "pipe" });
const stdoutReader = (child.stdout as ReadableStream<Uint8Array>).getReader();
const stderrReader = (child.stderr as ReadableStream<Uint8Array>).getReader();

Binary Existence Checks

// GOOD: Bun.which (cross-platform)
const gitPath = Bun.which("git");
if (!gitPath) throw new Error("git not found");

// BAD: Spawning which/where (platform-specific)
Bun.spawnSync(["which", "git"]);  // Unix only
Bun.spawnSync(["where", "git"]);  // Windows only

Path Resolution

// GOOD: import.meta (Bun ESM)
const thisDir = import.meta.dir;      // equivalent to __dirname
const thisFile = import.meta.path;    // equivalent to __filename

// BAD: fileURLToPath dance
import { fileURLToPath } from "url";
import { dirname } from "path";
const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);

Crypto

// GOOD: Web Crypto (standard) or Bun.hash
const uuid = crypto.randomUUID();
const bytes = crypto.getRandomValues(new Uint8Array(32));
const hash = Bun.hash("sha256", data);

// BAD: Node crypto
import { randomBytes, randomUUID } from "node:crypto";

Environment Variables

Bun auto-loads .env files. Do NOT import dotenv.

// GOOD: Direct access
const apiKey = process.env.API_KEY;

// BAD: dotenv
import dotenv from "dotenv";
dotenv.config();

HTTP Servers

// GOOD: Bun.serve
const server = Bun.serve({
   port: 3000,
   fetch(req) {
      return new Response("OK");
   },
});
// later: server.stop();

// BAD: Node http
import http from "node:http";
const server = http.createServer((req, res) => { ... });

HTTP Requests

// GOOD: Native fetch (built into Bun)
const response = await fetch("https://api.example.com/data");
const json = await response.json();

// BAD: External packages
import fetch from "node-fetch";
import axios from "axios";

Password Hashing

// GOOD: Bun.password (bcrypt/argon2 built-in)
const hash = await Bun.password.hash("password", "bcrypt");
const valid = await Bun.password.verify("password", hash);

// BAD: External packages
import bcrypt from "bcrypt";
import argon2 from "argon2";

Watch Mode

# GOOD: Bun built-in watch/hot reload
bun --watch src/index.ts    # Restart on changes
bun --hot src/index.ts      # Hot reload without restart

# BAD: External tools
npx nodemon src/index.ts
npx ts-node-dev src/index.ts

SQLite

// GOOD: Bun built-in SQLite
import { Database } from "bun:sqlite";
const db = new Database("mydb.sqlite");
db.run("CREATE TABLE IF NOT EXISTS users (id INTEGER PRIMARY KEY, name TEXT)");

// BAD: External packages
import Database from "better-sqlite3";

Testing

# GOOD: Bun built-in test runner
bun test

# BAD: External test runners
npx jest
npx vitest
npx mocha

See docs/bun-migration-guide.md for full migration reference.

Commands

• After code changes: bun run check (get full output, no tail)
• For auto-fixable lint issues: bun run fix (includes unsafe fixes)
• NEVER run: bun run dev, bun run build, bun test
• Only run specific tests if user instructs: bun test test/specific.test.ts
• NEVER commit unless user asks
• Do NOT use tsc or npx tsc - always use bun run check which runs the correct type checker

GitHub Issues

When reading issues:

• Always read all comments on the issue

When creating issues:

• Add pkg:* labels to indicate which package(s) the issue affects
  • Available labels: pkg:agent, pkg:ai, pkg:coding-agent, pkg:mom, pkg:tui, pkg:web-ui
• If an issue spans multiple packages, add all relevant labels

When closing issues via commit:

• Include fixes #<number> or closes #<number> in the commit message
• This automatically closes the issue when the commit is merged

Tools

• GitHub CLI for issues/PRs
• Add package labels to issues/PRs: pkg:agent, pkg:ai, pkg:coding-agent, pkg:mom, pkg:tui, pkg:web-ui
• TUI interaction: use tmux

Style

• Keep answers short and concise
• No emojis in commits, issues, PR comments, or code
• No fluff or cheerful filler text
• Technical prose only, be kind but direct (e.g., "Thanks @user" not "Thanks so much @user!")

Changelog

Location: packages/*/CHANGELOG.md (each package has its own)

Format

Use these sections under ## [Unreleased]:

• ### Breaking Changes - API changes requiring migration
• ### Added - New features
• ### Changed - Changes to existing functionality
• ### Fixed - Bug fixes
• ### Removed - Removed features

Rules

• New entries ALWAYS go under ## [Unreleased] section
• NEVER modify already-released version sections (e.g., ## [0.12.2])
• Each version section is immutable once released

Attribution

• Internal changes (from issues): Fixed foo bar ([#123](https://github.com/badlogic/pi-mono/issues/123))
• External contributions: Added feature X ([#456](https://github.com/badlogic/pi-mono/pull/456) by [@username](https://github.com/username))

Releasing

1. Update CHANGELOGs: Ensure all changes since last release are documented in the [Unreleased] section of each affected package's CHANGELOG.md

2. Run release script:

   npm run release:patch    # Bug fixes
   npm run release:minor    # New features
   npm run release:major    # Breaking changes
   

The script handles: version bump, CHANGELOG finalization, commit, tag, publish, and adding new [Unreleased] sections.