Desktop MCP

MCP servers for desktop applications — give AI assistants access to Thunderbird (email, calendar, contacts) and Firefox (browser automation).

Packages

Package	Description	npm
thunderbird-mcp	Email, calendar, tasks, contacts, feeds via Thunderbird	npm i thunderbird-mcp
firefox-mcp	Browser automation via Firefox	npm i firefox-mcp
@desktop-mcp/shared	Shared backend: native messaging, MCP server factory, install helpers	internal

Architecture

Both packages follow the same pattern:

MCP Client  <--HTTP-->  Node.js Server  <--native messaging-->  Browser Extension

• Streamable HTTP transport (MCP SDK) between AI client and server
• Native messaging (stdin/stdout, 4-byte framed) between server and extension
• Shared BaseBrowserAPI class handles correlation-ID-based request/response
• Shared createServer factory sets up McpServer + HTTP + plugin loading

Quick start

git clone https://github.com/hmblair/desktop-mcp.git
cd desktop-mcp
npm install
npm run build -w packages/shared

# Thunderbird
npm run build -w packages/thunderbird
cd packages/thunderbird && make && make install

# Firefox
npm run build -w packages/firefox
cd packages/firefox && make && make install

See each package's README for detailed setup instructions.

Development

npm run build -w packages/shared      # Build shared (required first)
npm run build -w packages/firefox     # Build firefox server + extension
npm run build -w packages/thunderbird # Build thunderbird server
npm run test -w packages/firefox      # Smoke test firefox
npm run test -w packages/thunderbird  # Smoke test thunderbird

Acknowledgments

This project began as two separate forks, both substantially rewritten since:

• thunderbird-mcp — forked from TKasperczyk/thunderbird-mcp by Tomasz Kasperczyk.
• firefox-mcp — forked from eyalzh/browser-control-mcp by eyalzh (named firefox-mcp at the time of the fork).

License

MIT. See LICENSE and individual package licenses.