Mu MCP

Mu MCP is an MCP server that connects AI assistants to a local mu mail index for fast, structured email search and retrieval. Designed for developers, researchers, and professionals managing local maildir archives, the server bridges Claude Desktop and other Model Context Protocol clients with the underlying mu CLI utility. By running over standard input and output (stdio), it provides tools to query local mail stores using flexible search criteria, view specific email message contents, and identify attachments. Users can prompt their assistant to inspect email bodies, locate correspondence across historical mailboxes, and trigger the operating system's default viewer to open downloaded file attachments directly. The system operates on Python and the official MCP SDK, offering integration through package managers like pixi. Because it runs locally against an existing mu database, email data remains entirely on the host machine rather than relying on external webmail APIs. This architecture provides a fast, offline-capable interface for inspecting personal or technical communications through conversational workflows.

Category: Communication & Messaging

Tags: email, mail-index, mu, search

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How to install and configure Mu MCP

1. Clone the repository and install dependencies using pixi: sh git clone https://github.com/danielfleischer/mu-mcp.git cd mu-mcp pixi install 2. Verify the server runs standalone by executing pixi run start or python mu_mcp/mu_mcp.py. 3. Register the server in your claude_desktop_config.json file: json "mcpServers": { "mu_mcp": { "command": "pixi", "args": [ "run", "--manifest-path", "PROJECT_PATH", "start" ] } } Replace PROJECT_PATH with the absolute path to your cloned repository, then restart Claude Desktop.

What you can do with Mu MCP

• Search local email archives for messages sent within specific date ranges containing specific sender names or keywords in the subject line. - Locate emails containing specific document attachments such as PDF reports and open those files in the operating system's default viewer. - Retrieve and review the full text content of historical email discussions directly within a Claude conversation thread. - Filter indexed maildir mailboxes to find meeting notes, technical discussions, or invoices without querying external cloud webmail services.

Key facts

• Open Source
• https://github.com/danielfleischer/mu-mcp
• Communication & Messaging, Web Search & Research
• email, mail-index, mu, search

Part of MCP Servers

How do I install Mu MCP?

To install Mu MCP, clone the repository using git and navigate into the project folder. Ensure pixi is installed on your machine, then run pixi install to set up the necessary Python environment and dependencies. Once the environment is installed, you can configure your MCP client to start the server.

What can Mu MCP do?

Mu MCP allows MCP clients to interact directly with your local mu email index. It provides three primary capabilities: querying indexed mail with custom search parameters, viewing email body contents in conversation, and finding or opening file attachments using your operating system default viewing application.

Which MCP clients work with Mu MCP?

Mu MCP works with Claude Desktop and any other Model Context Protocol client supporting stdio transport. It communicates over standard input and output, making it compatible with any local desktop client or command-line developer environment that can spawn processes defined in an MCP configuration file.

Is Mu MCP open source?

Yes, Mu MCP is open source software hosted on GitHub. It is distributed under an open source license, allowing users to inspect the Python source code, modify tools, contribute improvements, and configure custom mail-handling workflows for their personal local setups.