TKasperczyk/thunderbird-mcp

What it solves

Thunderbird lacks an official API for AI tools, preventing AI assistants from interacting with your email, calendar, and contacts. This project provides a bridge that allows compatible AI clients (like Claude or GPT) to search, read, compose, and organize your Thunderbird data using the Model Context Protocol (MCP).

How it works

The system consists of two main parts: a Thunderbird extension that embeds a local HTTP server with session-scoped authentication, and a Node.js bridge (mcp-bridge.cjs). The bridge translates the MCP stdio protocol used by AI clients into HTTP requests that the extension's server can understand. It automatically discovers the connection details (port and token) via a local connection file, supporting various installation environments including native, Snap, and Flatpak.

Who it’s for

Users of the Mozilla Thunderbird email client who want to integrate their local mail and scheduling data with AI assistants for automated drafting, inbox organization, and calendar management.

Highlights

• Comprehensive Toolset: Exposes 40 tools for managing mail (search, read, move, delete), composing messages (send, reply, forward), managing filters, contacts, and calendar events/tasks.
• Safety First: Includes a "Block skipReview" setting enabled by default, ensuring that no emails are sent or calendar events created without explicit user review.
• Privacy-Centric: The server binds to localhost by default and uses session-scoped bearer tokens for authentication.
• Cross-Platform Support: Built-in discovery for connection files across macOS, Linux (Snap/Flatpak), and native installs.
• Granular Access Control: Users can restrict which email accounts and specific tools are visible and accessible to the AI assistant via the extension settings.