MCP GitHub Navigator

A Model Context Protocol (MCP) server that provides an AI agent with secure access to GitHub data, allowing it to list repositories, view issues, and read files via the GitHub API.

HLD (High-Level Design)

• Architecture: The server is built in Node.js/TypeScript and implements the standard MCP @modelcontextprotocol/sdk. It uses a StdioServerTransport to communicate directly with any MCP-compatible AI client via standard input/output.
• External Integration: Uses Axios to connect to the GitHub REST API (https://api.github.com).
• Authentication: Relies on a Personal Access Token provided via the GITHUB_TOKEN environment variable.

LLD (Low-Level Design)

• Entry Point: src/index.ts is the main entry point which initializes the Server instance and maps MCP capabilities.
• Tools Registered:
  • get_user: Uses GET /user to return the authenticated GitHub profile.
  • list_repos: Uses GET /user/repos?sort=updated&per_page=10 to return recently active repositories.
• Data Flow: When an AI client sends a CallToolRequestSchema for list_repos, the MCP server validates the tool name, invokes the corresponding GitHub API endpoint via Axios, formats the JSON response into a text block, and returns it to the client.

TDD (Test-Driven Development) Strategy

• Frameworks: We recommend using Jest for executing test suites.
• Mocking: Testing relies on mocking the axiosInstance using libraries like nock or axios-mock-adapter to simulate GitHub API responses without requiring an active internet connection or hitting API rate limits.
• Integration Tests: Creating a mock MCP Client using @modelcontextprotocol/sdk/client to test the end-to-end flow of standard CallTool requests.

Setup Instructions

Prerequisites

• Node.js (v16 or higher)
• A GitHub Personal Access Token (PAT)

Installation

1. Clone the repository:

   git clone https://github.com/RachitJava/mcp-github.git
   cd mcp-github
   

2. Install dependencies:

   npm install
   

3. Build the project:

   npm run build
   

Running the Server

The server requires the GITHUB_TOKEN environment variable to be set. You can run it directly:

export GITHUB_TOKEN="your_personal_access_token_here"
npm start

Note: Since this is an MCP server, it is meant to be run by an MCP client (like Claude Desktop) rather than manually.