GitLab MCP Server

A Model Context Protocol (MCP) server for GitLab integration, written in TypeScript. This server allows you to interact with GitLab merge requests through MCP tools.

Features

• 🔍 Get merge request details (title, description, metadata)
• 📄 Retrieve merge request diffs
• 📋 List merge requests for a project
• 🔐 Supports self-hosted GitLab instances
• 🔑 Token-based authentication via environment variables

Installation

1. Clone or download this repository
2. Install dependencies:

   npm install

3. Build the project:

   npm run build

Configuration

Set the following environment variables:

Required

• GITLAB_HOST: Your GitLab instance URL (e.g., https://gitlab.example.com or https://gitlab.com)
• GITLAB_API_TOKEN: Your GitLab access token

Optional (for multiple instances)

• MCP_INSTANCE_ID: Unique identifier for the server instance (useful for logging and identification)

You can copy .env.example to .env and fill in your values:

cp .env.example .env
# Edit .env with your GitLab configuration

Getting a GitLab Access Token

1. Go to your GitLab instance
2. Navigate to User Settings → Access Tokens
3. Create a new token with api scope
4. Copy the token and set it as GITLAB_API_TOKEN

Usage

Running the Server

Single Instance

# Development mode
npm run dev

# Production mode
npm run build && npm start

Multiple Instances

Each instance runs as a separate process with its own configuration:

# Build first
npm run build

# Instance 1 (in terminal 1)
GITLAB_HOST=https://gitlab.example.com GITLAB_API_TOKEN=token1 MCP_INSTANCE_ID=instance1 npm start

# Instance 2 (in terminal 2)
GITLAB_HOST=https://gitlab.com GITLAB_API_TOKEN=token2 MCP_INSTANCE_ID=instance2 npm start

# Instance 3 (in terminal 3)
GITLAB_HOST=https://gitlab.internal.com GITLAB_API_TOKEN=token3 MCP_INSTANCE_ID=instance3 npm start

Each instance can connect to different GitLab hosts with different tokens, allowing multiple tools to work with different GitLab environments simultaneously.

Available Tools

get_merge_request

Get detailed information about a specific merge request, optionally including the diff/changes.

Parameters:

• projectId (string): GitLab project ID or path (e.g., "group/project" or "123")
• mergeRequestIid (number): Merge request internal ID (IID)
• includeDiff (optional boolean): Whether to include the diff/changes in the response (default: false)

list_merge_requests

List merge requests for a project.

Parameters:

• projectId (string): GitLab project ID or path
• state (optional string): Filter by state ("opened", "closed", "merged", "all"). Default: "opened"

Example Usage with MCP Client

// Get merge request details only
await callTool("get_merge_request", {
  projectId: "mygroup/myproject",
  mergeRequestIid: 42
});

// Get merge request details with diff
await callTool("get_merge_request", {
  projectId: "123",
  mergeRequestIid: 42,
  includeDiff: true
});

// List open merge requests
await callTool("list_merge_requests", {
  projectId: "mygroup/myproject",
  state: "opened"
});

Multiple Instance Setup

When running multiple instances, each tool/client can connect to a different instance:

MCP Client Configuration Example

{
  "mcpServers": {
    "gitlab-company": {
      "command": "node",
      "args": ["path/to/gitlab-mcp/dist/index.js"],
      "env": {
        "GITLAB_HOST": "https://gitlab.example.com",
        "GITLAB_API_TOKEN": "company_token",
        "MCP_INSTANCE_ID": "company"
      }
    },
    "gitlab-personal": {
      "command": "node",
      "args": ["path/to/gitlab-mcp/dist/index.js"],
      "env": {
        "GITLAB_HOST": "https://gitlab.com",
        "GITLAB_API_TOKEN": "personal_token",
        "MCP_INSTANCE_ID": "personal"
      }
    },
    "gitlab-internal": {
      "command": "node",
      "args": ["path/to/gitlab-mcp/dist/index.js"],
      "env": {
        "GITLAB_HOST": "https://gitlab.internal.company.com",
        "GITLAB_API_TOKEN": "internal_token",
        "MCP_INSTANCE_ID": "internal"
      }
    }
  }
}

This allows different tools to connect to different GitLab instances simultaneously, each with their own authentication and configuration.

Development

The project uses TypeScript and the MCP SDK. Key files:

• src/index.ts: Main MCP server implementation
• src/gitlab-client.ts: GitLab API client wrapper
• package.json: Dependencies and scripts
• tsconfig.json: TypeScript configuration

License

MIT