🚀 MCP Server with Authentication and Testing with Inspector

This project implements a Model Context Protocol (MCP) server with two authentication mechanisms: API Key Authentication and JWT (JSON Web Token) Authentication. It provides a robust framework for handling authenticated requests with comprehensive error handling and logging, suitable for production environments. The server supports tools like echo, login, secure_action, and admin_action, with authentication enforced where required.

📚 Table of Contents

1. 🚀 Project Overview

2. 🎯 Purpose

3. ✨ Features

4. 🗂️ Project Structure

5. ✅ Prerequisites

6. ⚙️ Installation

   • 📥 Clone the Repository

   • 🪄 Set Up a Virtual Environment

   • 📦 Install Dependencies

7. 🧩 Packages

8. 🚦 Usage

   • 1️⃣ MCP Server with Stdio and API Key

     • ▶️ Run the MCP Server

     • ▶️ Run the MCP Inspector

     • 🌐 Open the MCP Inspector

     • 🧪 Using the MCP Inspector

   • 2️⃣ MCP Server with Stdio and JWT

     • ▶️ Run the MCP Server

     • ▶️ Run the MCP Inspector

     • 🌐 Open the MCP Inspector

     • 🧪 Using the MCP Inspector

   • 3️⃣ MCP Server with Stdio and Auth2 (To Do)

9. 🔄 Workflow

10. 🩵 Troubleshooting

• 🚫 Invalid API Key

• ⚠️ Invalid JWT Token

• 🔒 Permission Errors

• 📝 Log Files

🎯 Purpose

The purpose of this project is to demonstrate secure MCP server implementations with two distinct authentication methods:

• 🔑 API Key Authentication: Validates requests using predefined API keys.

• 🛡️ JWT Authentication: Uses JSON Web Tokens for user authentication and permission-based access control.

This project is designed for developers who need a secure, scalable, and extensible MCP server with robust debugging and logging capabilities.

Related MCP server: Echo MCP Server

✨ Features

• 🔑 API Key Authentication:

  • Validates requests using a set of predefined API keys.

  • Supports key extraction from arguments, metadata, or environment variables.

  • Simple echo tool for demonstration.

• 🛡️ JWT Authentication:

  • Supports user authentication via username/password to generate JWT tokens.

  • Enforces permission-based access control (read, write, admin).

  • Includes tools: login, echo, secure_action, and admin_action.

  • Configurable token expiry (default: 24 hours).

  • Token extraction from arguments, metadata, or environment variables.

• ⚠️ Robust Error Handling:

  • Custom McpError for consistent error responses.

  • Detailed logging of errors and server events.

• 📝 Logging:

  • Configurable logging to both console and rotating log files.

  • Log rotation based on file size (5MB, with 5 backups).

  • Automatic cleanup of old log files based on age.

• 🔍 MCP Inspector Integration:

  • Compatible with MCP Inspector for testing and debugging.

  • Supports debugging via --debug flag.

🗂️ Project Structure

/
├── src/
│   ├── config/
│   │   ├── __init__.py
│   │   ├── app_settings.py                     # Configuration for environment variables and settings
│   │   └── logging_config.py                   # Logging setup with file rotation
│   ├── mcp-server-with-stdio-api-key-auth.py   # API Key Authentication server
│   ├── mcp-server-with-stdio-auth2-auth.py     # To Do
│   └── mcp-server-with-stdio-jwt-key-auth.py   # JWT Authentication server
├── pyproject.toml                              # Project documentation
└── README.md                                   # Python dependencies

✅ Prerequisites

• Python: Version 3.13 or higher

• uv: Used for managing Python virtual environments

• Node.js: Required for running MCP Inspector

• NPM: Required to run MCP Inspector

• Operating System: Windows, macOS, or Linux

⚙️ Installation

1. 📥 Clone the Repository:

   git clone https://github.com/ahmad-act/MCP-Server-with-Authentication-and-Testing-with-Inspector.git
   cd MCP-Server-with-Authentication-and-Testing-with-Inspector

2. 🪄 Set Up a Virtual Environment (recommended):

   uv venv
   source venv/bin/activate  # On Windows: venv\Scripts\activate

3. 📦 Install Dependencies:

   uv sync

🧩 Packages

The following Python packages are required:

mcp[cli]>=1.10.1
PyJWT>=2.8.0
python-dotenv>=1.0.0

👉 Install them using:

uv add mcp[cli] PyJWT python-dotenv

🚦 Usage

1️⃣ MCP Server with Stdio and API Key (mcp-server-with-stdio-api-key-auth.py)

▶️ Run the MCP Server:

⚠️ You do not need to manually run the MCP server for stdio transport. MCP Inspector runs the MCP Server for stdio transport.

▶️ Run the MCP Inspector:

The stdio server is typically launched by the MCP Inspector, not manually. Run the Inspector with the following command, add -e environment variable and adjusting the --directory path to your src/ directory:

npx @modelcontextprotocol/inspector uv -e MCP_API_KEY=sk-1234567890abcdef --directory '<your-src-directory>/src' run mcp-server-with-stdio-api-key-auth.py --debug

🌐 Open the MCP Inspector:

Open the link http://localhost:6274/?MCP_PROXY_AUTH_TOKEN=XXXXXXXXXXXXXXXXXX with its token in your browser:

🧪 Using the MCP Inspector

1. After running the above command, the Inspector will start and automatically connect to the stdio-based server.

2. In the Inspector UI (http://127.0.0.1:6274), inspect the available tools (e.g., echo).

3. Test the echo tool:

   • Input:

   {
     "method": "call_tool",
     "params": {
       "name": "echo",
       "arguments": {
         "message": "test",
         "_api_key": "sk-1234567890abcdef"
       }
     }
   }

   Expected Response:

   {
     "result": [
       {
         "type": "text",
         "text": "Echo: test"
       }
     ]
   }

   

2️⃣ MCP Server with Stdio and API Key (mcp-server-with-stdio-jwt-key-auth.py)

▶️ Run the MCP Server:

⚠️ You do not need to manually run the MCP server for stdio transport. MCP Inspector will launch the server automatically.

▶️ Run the MCP Inspector:

The stdio server is typically launched by the MCP Inspector, not manually. Run the Inspector with the following command, adjusting the --directory path to your src/ directory:

npx @modelcontextprotocol/inspector uv --directory '<your-src-directory>\src' run mcp-server-with-stdio-jwt-key-auth.py --debug

🌐 Open the MCP Inspector:

Open the link http://localhost:6274/?MCP_PROXY_AUTH_TOKEN=XXXXXXXXXXXXXXXXXX with its token in your browser:

🧪 Using the MCP Inspector

1. After running the above command, the Inspector will start and automatically connect to the stdio-based server.

2. Usage Flow:

   • Step 1: Login to Get JWT Token:

     {
       "method": "call_tool",
       "params": {
         "name": "login",
         "arguments": {
           "username": "user1",
           "password": "password123"
         }
       }
     }

     Response:

     {
       "result": [
         {
           "type": "text",
           "text": "Login successful! JWT Token: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
         }
       ]
     }

   • Step 2: Use JWT Token for Authenticated Requests:

     {
       "method": "call_tool",
       "params": {
         "name": "echo",
         "arguments": {
           "message": "test",
           "_jwt_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
         }
       }
     }

     Response:

     {
       "result": [
         {
           "type": "text",
           "text": "Echo (authenticated as user1): test"
         }
       ]
     }

   

3️⃣ MCP Server with Stdio and Auth2 (mcp-server-with-stdio-auth2-auth.py)

🚧 To Do

🔄 Workflow

1. 🔑 API Key Authentication:

   • The server checks for a valid API key in the request arguments, metadata, or environment variables.

   • If valid, the request is processed; otherwise, an error is returned.

   • The echo tool demonstrates basic functionality.

2. 🛡️ JWT Authentication:

   • Users first call the login tool with valid credentials to obtain a JWT token.

   • The token is used in subsequent requests for tools like echo, secure_action, or admin_action.

   • Permissions (read, write, admin) are checked for each tool.

   • Tokens expire after 24 hours (configurable).

3. 📝 Logging:

   • Logs are written to both the console and a rotating log file in the logs directory.

   • Old log files are cleaned up based on a specified retention period.

4. 🔍 Testing with MCP Inspector:

   • Use MCP Inspector to interact with the server via a web interface.

   • Debug mode (--debug) provides detailed output for troubleshooting.

🩵 Troubleshooting

• 🚫 Invalid API Key:

  • Ensure the API key is one of: sk-1234567890abcdef, sk-abcdef1234567890, sk-test123456789.

  • Check environment variable MCP_API_KEY or request arguments.

• ⚠️ Invalid JWT Token:

  • Verify the token is not expired (valid for 24 hours).

  • Ensure the correct JWT_SECRET is set.

  • Check username/password for login tool.

• 🔒 Permission Errors:

  • Ensure the user has the required permissions (read, write, or admin) for the requested tool.

• 📝 Log Files:

  • Check the logs directory for detailed error messages.

  • Logs are named in the format YYYYMM.log.