expo-mcp: Instructions file for Codex

Agent Guidelines for expo-mcp-monorepo

Build, Lint, and Test Commands

Root Level

# Build all packages
bun run build

# Lint all packages
bun run lint

# Test all packages
bun run test

Per Package

# Navigate to package directory
cd packages/mcp-tunnel  # or cd packages/expo-mcp

# Build
bun run build
# Equivalent: tsc --project tsconfig.build.json

# Lint
bun run lint
# Equivalent: eslint src

# Test
bun run test
# Equivalent: bun test

# Type check
bun run typecheck
# Equivalent: tsc --noEmit

Running Single Tests

# Run all tests in a specific file
bun test packages/mcp-tunnel/src/__tests__/ReverseTunnelClientTransport.test.ts

# Run a single test by line number
bun test packages/mcp-tunnel/src/__tests__/ReverseTunnelClientTransport.test.ts:72

# Run specific test in a file
bun test packages/mcp-tunnel/src/__tests__/ReverseTunnelClientTransport.test.ts:72-95

Code Style Guidelines

General

• Runtime: Bun runtime (ECMAScript modules)
• Language: TypeScript 5.9.2+
• Type checking: Strict mode enabled (tsconfig.base.json:strict: true)
• Format: Prettier 3.6.2 (uses catalog defaults)

Imports and Modules

• Use ES modules: "type": "module" in package.json
• Import with .js extensions in import statements for files within monorepo
• Use import.meta.url and createRequire for CommonJS compatibility
• Sort imports with sort-imports rule (ignoreDeclarationSort, check memberSort)

import { type Transport } from '@modelcontextprotocol/sdk/shared/transport.js';
import type { JSONRPCMessage } from '@modelcontextprotocol/sdk/types.js';
import WebSocket from 'ws';
import { createRequire } from 'node:module';

const require = createRequire(import.meta.url);

Formatting

• Follow Prettier defaults (no explicit config found, uses catalog version)
• Run bun run lint to format automatically

TypeScript

• Target: ESNext with bundler module resolution
• Use modern TypeScript syntax
• Prefer const assertions and nullish coalescing
• Use type aliases for complex types