Mattermost MCP Server

A Model Context Protocol (MCP) server for interacting with Mattermost workspaces. This server provides tools for managing channels, messages, threads, reactions, and user profiles through Mattermost's REST API.

Built on Cloudflare Workers using the Agents SDK.

Important: This is an MCP server without OAuth authentication, designed for trusted environments where the server runs with pre-configured API credentials.

Features

Tools (9 Total)

Read Operations (6 tools):

• list_mattermost_channels - List all channels in the team
• get_mattermost_channel_history - Get message history from a channel
• get_mattermost_thread_replies - Get all replies in a thread
• get_mattermost_users - List users in the workspace
• get_mattermost_user_profile - Get detailed profile for a specific user

Write Operations (3 tools):

• post_mattermost_message - Post a new message to a channel
• reply_to_mattermost_thread - Reply to an existing thread
• add_mattermost_reaction - Add emoji reactions to posts
• create_mattermost_direct_channel - Create a direct message channel with a user

Prompts (2 Total)

• mattermost_guide - Comprehensive guide for using Mattermost effectively
• message_template - Helpful templates for crafting effective Mattermost messages

Resources (2 Total)

• mattermost://channels - List of all channels in the team
• mattermost://users - List of all users in the workspace

Architecture

This MCP server is built using:

• Cloudflare Workers: Serverless compute
• Agents SDK: Framework for building AI agents and MCP Servers
• Durable Objects: For persistent MCP session state
• Mattermost REST API v4: For workspace integration

Prerequisites

• Node.js 18+
• A Mattermost instance (self-hosted or cloud)
• Personal Access Token from Mattermost (Profile → Security → Personal Access Tokens)
• Team ID from your Mattermost workspace

Quick Start

Local Development

1. Clone the repository:

git clone https://github.com/vnikhilbuddhavarapu/mattermost-mcp.git
cd mattermost-mcp

2. Install dependencies:

npm install

3. Configure environment variables:

cp .dev.vars.example .dev.vars

Edit .dev.vars with your Mattermost credentials:

MATTERMOST_URL=https://mattermost.your-domain.com
MATTERMOST_TOKEN=your-personal-access-token
MATTERMOST_TEAM_ID=your-team-id

Finding your Team ID:

curl -H "Authorization: Bearer YOUR_TOKEN" \
  https://mattermost.your-domain.com/api/v4/teams | jq '.[].id'

4. Run locally:

npm run dev

Deploy to Cloudflare Workers

1. Click the deploy button above or run:

npm run deploy

2. Set your secrets:

npx wrangler secret put MATTERMOST_URL
npx wrangler secret put MATTERMOST_TOKEN
npx wrangler secret put MATTERMOST_TEAM_ID

Configuration

Environment Variables

Variable	Required	Description
MATTERMOST_URL	Yes	Your Mattermost instance URL (e.g., https://mattermost.example.com)
MATTERMOST_TOKEN	Yes	Personal Access Token from Mattermost
MATTERMOST_TEAM_ID	Yes	Team ID (get via API, not team name)

Usage with MCP Clients

Claude Desktop

Add to your Claude Desktop configuration (~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "mattermost": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://mattermost-mcp.your-account.workers.dev/mcp"],
      "env": {
        "MATTERMOST_URL": "https://mattermost.your-domain.com",
        "MATTERMOST_TOKEN": "your-token-here",
        "MATTERMOST_TEAM_ID": "your-team-id"
      }
    }
  }
}

Other MCP Clients

Connect to the MCP endpoint:

https://mattermost-mcp.your-account.workers.dev/mcp

Project Structure

src/
├── index.ts                 # Main MCP server setup and Durable Object
├── mattermost-client.ts     # REST API client for Mattermost
├── shared/
│   └── utils.ts            # Logging utilities and request ID generation
├── tools/                   # MCP tool implementations
│   ├── list-channels.ts
│   ├── get-channel-history.ts
│   ├── post-message.ts
│   ├── reply-to-thread.ts
│   ├── get-thread-replies.ts
│   ├── add-reaction.ts
│   ├── get-users.ts
│   ├── get-user-profile.ts
│   ├── create-direct-channel.ts
│   └── index.ts            # Tool exports
├── prompts/                # MCP prompt templates
│   ├── mattermost-guide.ts
│   ├── message-template.ts
│   └── index.ts            # Prompt exports
└── resources/              # MCP resources
    ├── channels-list.ts
    ├── users-list.ts
    └── index.ts            # Resource exports

wrangler.jsonc              # Cloudflare Workers configuration
worker-configuration.d.ts  # TypeScript types for bindings

API Reference

Mattermost REST API v4

This server uses the Mattermost REST API v4. Key endpoints used:

Get Channels:

GET /api/v4/teams/{team_id}/channels

Get Posts:

GET /api/v4/channels/{channel_id}/posts

Create Post:

POST /api/v4/posts
{
  "channel_id": "...",
  "message": "...",
  "root_id": "..."  // optional, for threads
}

Add Reaction:

POST /api/v4/reactions
{
  "post_id": "...",
  "emoji_name": "..."
}

Documentation

• Cloudflare Agents SDK - Remote MCP Server Guide
• Cloudflare Workers Documentation
• Cloudflare MCP Server Docs
• Mattermost REST API Docs
• Model Context Protocol Spec

License

MIT

Connect to Cloudflare AI Playground

You can connect to your MCP server from the Cloudflare AI Playground, which is a remote MCP client:

1. Go to https://playground.ai.cloudflare.com/
2. Enter your deployed MCP server URL (mattermost-mcp.<your-account>.workers.dev/mcp)
3. You can now use your MCP tools directly from the playground!

Connect Claude Desktop to your MCP server

You can also connect to your remote MCP server from local MCP clients, by using the mcp-remote proxy.

To connect to your MCP server from Claude Desktop, follow Anthropic's Quickstart and within Claude Desktop go to Settings > Developer > Edit Config.

Update with this configuration:

{
  "mcpServers": {
    "mattermost": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "https://mattermost-mcp.your-account.workers.dev/mcp"
      ]
    }
  }
}

Restart Claude and you should see the tools become available.