Mattermost

io.github.vriesdemichaelv0.1.0Updated Oct 8, 2026

Read, search and post in Mattermost as yourself or a bot.

VerifiedSTDIODesktop onlyCommunication & Collaboration

Overview

AI-generated overview

Lets an assistant read, search and, when explicitly allowed, post and reply in Mattermost as you or as a bot.

What it does
An MCP server for Mattermost that gives an assistant access to your chat workspace. It reads channels, threads, unread posts and files, and searches posts, files, people and channels. With writes enabled it can post, reply, edit, react, pin and keep drafts. It runs as a local process over stdio, or serves Streamable HTTP on a loopback address.
When to use it
Useful when you want an assistant to catch up on unread channels, find a discussion or file, or draft and send replies without leaving your client. Worth adding if your team works in Mattermost and you want search and posting handled conversationally.
Requirements
A local runtime: install the binary via Homebrew, winget, Scoop or a release download, or open the .mcpb bundle in Claude Desktop. Requires MM_URL (your Mattermost address) and MM_TOKEN (a personal access token, bot token or session token). Optional settings: MM_MCP_ALLOW_WRITES, MM_MCP_DOWNLOAD_DIR, MM_MCP_MARK_AI_GENERATED. Network access to your Mattermost server.
Before you install
MM_TOKEN is a credential that acts as you or as a bot; anyone with it can read and write your Mattermost. Writes are off until MM_MCP_ALLOW_WRITES is true, and then posts, replies, edits, reactions and pins are visible to colleagues and ask for confirmation first, while thread following, saved posts, reminders, drafts and typing do not. Attachments are written to MM_MCP_DOWNLOAD_DIR. The project is early development and not affiliated with Mattermost, Inc.

Installation

In SourceWeft

  1. Open Mattermost in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

mm-mcp

[CI] [codecov]

An MCP server for Mattermost. It lets an AI agent read and search your Mattermost and, when you allow it, post and reply, as you or as a bot.

mm-mcp is an independent project. It is not affiliated with, endorsed by or supported by Mattermost, Inc.; Mattermost is a trademark of Mattermost, Inc.

Early development. Nothing is released yet. The tools read channels, threads, unread posts and files, search posts, files, people and channels, and, once you allow writes, post, reply, edit, react, pin and keep drafts. The tools page lists every one. Views in the chat for clients that render MCP Apps are planned; the issues are the plan.

Why it works the way it does

  • Read-only unless you say otherwise. The tools that post or change anything are not offered until MM_MCP_ALLOW_WRITES is true. Then every change others see asks you first: an agent acting with your token speaks as you to your colleagues. Following a thread, saving a post, a reminder, a draft only you see and the typing indicator are yours alone or gone in seconds, and do not ask.
  • Your token, a bot's, or your own login. A personal access token, a bot token, or the session token from logging in yourself, for servers where personal access tokens are switched off.
  • Mattermost's own client. Requests and answers use the server's own Go client and types, not a hand-written description of the API.
  • Every supported release, tested. Every tool runs against a real Mattermost Team Edition, on the Extended Support Release and the newest release on every change, and on every release between them each week.
  • stdio and Streamable HTTP. A client starts it as a local process, or it serves Streamable HTTP on a loopback address.

Quick start

Install mm-mcp with brew install vriesdemichael/tap/mm-mcp, winget install vriesdemichael.mm-mcp or scoop install vriesdemichael/mm-mcp (after scoop bucket add vriesdemichael https://github.com/vriesdemichael/scoop), or download the binary for your machine from the latest release. Then get a personal access token in Mattermost under Profile → Security → Personal Access Tokens.

json
{  "mcpServers": {    "mattermost": {      "command": "mm-mcp",      "args": ["serve"],      "env": {        "MM_URL": "https://chat.example.com",        "MM_TOKEN": "your-token"      }    }  }}

Or, for Claude Code:

bash
claude mcp add mattermost --env MM_URL=https://chat.example.com --env MM_TOKEN=your-token -- mm-mcp serve

Claude Desktop users can open the .mcpb bundle for their machine from the latest release instead.

The documentation has every setting, the tools, and the supported Mattermost releases.

Contributing

See CONTRIBUTING.md. The decisions behind how this project is built are in docs/site/adr.

License

Apache-2.0

Source: README.md at commit d224eb0

Tools

0
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Version history

1
  1. v0.1.0LatestOct 8, 2026