Mu MCP Server

Build agents with an inbox and tools. Chat with them in a browser, via API, CLI or by email. They have access to 100+ tools: news, mail, search, weather, markets, video, places, files, contacts, calendar, documents. It's a work in progress. It is available as a remote MCP endpoint.

Teams that want a hosted email endpoint instead of running a local process. The project is written in Go.

VERIFIED ACTIVE

LAST COMMIT 2026-08-24 · ★ 387 · #22 OF 75 MAINTAINED EMAIL · VERIFIED 2026-08-25

AGPL-3.0 · Go servers · how we verify → /methodology

01 · Install Mu

before you install - you'll need

Set MU_TOKEN, ANTHROPIC_API_KEY before connecting.

Claude Code

claude mcp add micro-mu --transport http https://micro.mu/mcp

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "micro-mu": {
      "url": "https://micro.mu/mcp"
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

https://micro.mu/mcp

transport: streamable-http

endpoint alive - responded to MCP initialize · probed 2026-08-25

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as remote - your agent's requests go to micro.mu

endpoint auth accepted our unauthenticated MCP initialize - no credentials needed to connect

license AGPL-3.0 - declared in the repository

registry vendor namespace mu.micro - domain-verified with the official MCP registry

03 · What Mu can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

Latest releases

v1.5.1 · 2026-08-24

v1.5.0 · 2026-08-23

v1.4.0 · 2026-08-18

04 · Who maintains Mu

mu is maintained by micro. It's the only MCP server we track from this author; the repo dates to Nov 2025.

05 · Facts

repository: github.com/micro/mu
website: https://micro.mu/
category: email - ranked #22 of 75 actively-maintained email servers as of 2026-08-25.
release cadence: 10+ releases in the last 90 days (latest 2026-08-24)
registry: mu.micro/mu (active, first published 2026-08-03)

06 · Mu FAQ

What is Mu?

Is Mu still maintained?

Yes - as of 2026-08-25, its last commit was 2026-08-24 and it shipped 10+ releases in the last 90 days. We re-verify nightly.

How do I install Mu?

Run `claude mcp add micro-mu --transport http https://micro.mu/mcp`. The README documents 2 environment variables (MU_TOKEN, ANTHROPIC_API_KEY) to set first. Set MU_TOKEN, ANTHROPIC_API_KEY before connecting. You can also paste the ready-made client config above.

Does Mu require authentication?

No - the endpoint accepted our unauthenticated MCP initialize when probed on 2026-08-25; you can connect without credentials.

07 · Alternatives to Mu

Alternatives to Mu

Maintained email servers if Mu isn't the fit.

More email MCP servers · e2a - email for AI agents · Outlook MCP · iCloud MCP · Multimail Dev MCP Server · Better Email MCP

More Go MCP servers · Trvl · JMAP Email · Gitcontribute · OPC-UA MCP Server · see all