Because it reads an index that already exists on disk, there is no OAuth flow, no provider API, and nothing leaves the machine — which is a different privacy posture from every hosted mail connector. The three capabilities chain naturally: the README's own example is finding emails with a PDF attachment from a given month and opening the PDF, which is one instruction covering search, read and open.
An MCP server over the `mu` mail indexer, so an assistant can search mail that is already indexed on your machine. Nothing is uploaded and no mail provider is involved: the queries run against the local index.
- Fast, flexible search over the mu index using its own query syntax — sender, subject, date range, attachment presence
- Reading a matched email in the conversation, not just its headers
- Opening an attachment in the default OS viewer, so a PDF found by search can be opened in the same instruction
A working `mu` mail index on the machine — the server queries it and does not build it. Python with pixi: clone and run `pixi install`, then `pixi run start`, or run `python mu_mcp/mu_mcp.py` directly. The client entry uses pixi with the manifest path pointing at the project. Transport is stdio. The package is `mu_mcp` (0.3.0 in pyproject).