Expo

Model Context Protocol (MCP) server capabilities for Expo and EAS workflows.

This repository contains:

• packages/expo-mcp: MCP tools, prompts, and docs resources for Expo projects
• packages/mcp-tunnel: stdio/tunnel proxy layer for local and remote MCP transport
• expo-mcp-server.mjs: dynamic launcher for Codex/Claude MCP config

What It Does

The Expo MCP server enables AI assistants to execute Expo and EAS operations:

Category	Capabilities
Project Setup	Initialize projects, install packages, prebuild native folders, inspect config
Cloud Builds	Create/list/view/cancel EAS builds
OTA Updates	Publish/list updates and create channels
App Submission	Submit iOS and Android builds
Diagnostics	Run expo doctor, check auth, inspect EAS project metadata
Docs Access	Search/fetch Expo docs and expose docs as MCP resources

Requirements

• Node.js 18+
• Bun (for local development scripts in this monorepo)
• Expo account
• EXPO_TOKEN for account/EAS actions in MCP tools
  • Create token: expo.dev/settings/access-tokens

Quick Start

bun install
bun run build

MCP Setup

Use the dynamic launcher so manual server start is not required:

{
  "mcpServers": {
    "expo-mcp-demo": {
      "command": "node",
      "args": [
        "D:/expo-mcp-demo/expo-mcp-server.mjs",
        "--root",
        "D:/expo-mcp-demo"
      ],
      "env": {
        "EXPO_TOKEN": "your_token_here"
      }
    }
  }
}

Optional launcher flags/env:

• --root / EXPO_PROJECT_ROOT: Expo project root
• --dev-server-url / EXPO_DEV_SERVER_URL: explicit Metro URL
• --mcp-server-url / EXPO_MCP_SERVER_URL: tunnel server URL

Dynamic behavior:

• If dev server URL is omitted, launcher auto-detects local Metro/Expo server.
• If tunnel URL is present, server runs in composite mode (stdio + tunnel).
• Otherwise server runs as stdio MCP only.

Tools

Project Management

• expo_init_project
• expo_install_packages
• expo_get_config
• expo_prebuild

EAS Build

• eas_build_create
• eas_build_list
• eas_build_status
• eas_build_cancel

EAS Update (OTA)

• eas_update_publish
• eas_update_list
• eas_channel_create

EAS Submit

• eas_submit_ios
• eas_submit_android

Utilities

• expo_doctor
• expo_whoami
• eas_project_info

Docs Tools

• expo_docs_list
• expo_docs_search
• expo_docs_get

Dev/Automation Tools

• open_devtools
• collect_app_logs
• expo_router_sitemap
• automation_tap
• automation_take_screenshot
• automation_find_view_by_testid
• automation_find_view
• automation_tap_by_testid
• automation_take_screenshot_by_testid
• automation_swipe
• automation_scroll
• automation_type_text
• automation_press_key

MCP Resources

Docs resources exposed by the server:

• expo://docs/llms
• expo://docs/llms-full
• expo://docs/llms-eas
• expo://docs/llms-sdk
• expo://docs/llms-sdk-v53.0.0
• expo://docs/llms-sdk-v52.0.0
• expo://docs/llms-sdk-v51.0.0
• expo://docs/eas-build
• expo://docs/eas-update
• expo://docs/eas-submit
• expo://docs/cli-reference

Output Formats

Expo/EAS tools support:

• markdown (default)
• json

Development

Root

bun run build
bun run lint
bun run test

Per package

cd packages/expo-mcp
bun run build
bun run lint
bun run test
bun run typecheck

How To Add a New Tool

1. Add tool implementation in packages/expo-mcp/src/mcp/tools/expo/*.ts or relevant module.
2. Register tool in packages/expo-mcp/src/mcp/tools.ts.
3. If tool needs docs references, update packages/expo-mcp/src/mcp/tools/expoDocs.ts.
4. Add/update output schema and error handling through expo-utils.
5. Run:
   • bun run typecheck in packages/expo-mcp
   • bun run build in packages/expo-mcp
   • bun run lint --max-warnings=0 in affected package(s)

Dependency Notes

• Runtime CLI execution uses npx expo and npx eas-cli.
• EAS commands require EXPO_TOKEN and run non-interactive in MCP context.
• Transport layer supports both newline JSON and Content-Length framing for MCP compatibility.

Troubleshooting

• Authentication required for EAS commands:
  • Set EXPO_TOKEN in MCP server environment.
• No dev server found:
  • Start Metro (npx expo start) or set EXPO_DEV_SERVER_URL.
• MCP startup/handshake issues:
  • Ensure launcher points to expo-mcp-server.mjs.
  • Rebuild changed packages (bun run build).

License

MIT