About Mermoz

Mermoz is an email app for the Mac. It connects to Gmail, keeps your whole mailbox on your Mac, and treats every thread like a task with a status: Unread, To do, Waiting, Done. New mail arrives with a suggested status and project, one key moves a thread on, and search answers instantly, even offline.

It is also built for the agents you already use. Everything the app does is available from the mermoz command line and from a built-in MCP server, so Claude, Codex or your own scripts can search, read, sort and draft mail. Sending stays with you: an agent's draft waits in your Review lane until you approve it.

Facts

• Platform: macOS 26 or later, downloaded from GitHub Releases.
• Mail: Gmail and Google Workspace accounts, several at once; Google Drive optional.
• Status: private beta (version 0.1.0) while Google reviews Mermoz's Gmail access. Join the list and you'll be invited.
• Price: free. License: open source (MIT), source on GitHub.
• Built with: a Rust daemon (mermozd) that owns sync and storage, a Rust CLI and MCP server, and a SwiftUI app.
• Privacy: no Mermoz server, no analytics; AI features are off until you turn them on. Details on the privacy page.

Who makes it

Mermoz is made by Clément Walter and developed in the open on GitHub, where every change, issue and release is public. Reach us through the contact page.

The name

In 1930, Jean Mermoz flew the Aéropostale mail across the South Atlantic, from Senegal to Brazil, in a little over twenty hours. Letters that used to take weeks by sea arrived in days. The Aéropostale pilots had a motto: « Le courrier doit passer », the mail must go through. Mermoz keeps that spirit: mail that moves, light and fast, without the heavy machinery around it.

For developers and agents

• Developer docs: the CLI, the MCP server and the JSON-RPC protocol.
• llms.txt: a summary of Mermoz for language models.