Discord MCP Server with Bearer Token Authentication

A secure Discord MCP (Model Context Protocol) server that provides Discord integration tools with JWT Bearer Token authentication.

🔐 Security Features

• Bearer Token Authentication using JWT tokens
• Discord token protection - tokens are embedded in JWT claims, not passed as parameters
• Audit logging - all tool calls are logged with user information
• Temporary bot connections - no persistent Discord bot instances
• RSA key pair encryption for token signing and verification

📋 Available Tools

🚀 Setup and Installation

Prerequisites

• Python 3.8+
• Discord bot token with appropriate permissions
• Virtual environment (recommended)

Installation

1. Install dependencies (already installed in your venv):

   pip install discord.py fastapi fastmcp uvicorn python-dotenv PyJWT
   

2. Create a Discord bot and get your bot token:

   • Go to Discord Developer Portal
   • Create a new application and bot
   • Copy the bot token
   • Invite the bot to your server with necessary permissions

3. Set up environment variables (optional):

   # Create .env file
   echo "DISCORD_TOKEN=your_discord_bot_token_here" > .env
   

🏃‍♂️ Running the Server

Start the Server

python app.py

The server will start on http://localhost:8000 and display:

• Available tools
• Authentication information
• Token generation instructions

Generate Access Token

Replace YOUR_DISCORD_TOKEN with your actual Discord bot token:

python -c "from app import generate_access_token; print(generate_access_token('YOUR_DISCORD_TOKEN'))"

🔧 Using the Server

Authentication

All requests must include a JWT Bearer token in the Authorization header:

Authorization: Bearer <your_jwt_token>

Making Tool Calls

Endpoint: POST /mcp/v1/tools/invoke

Headers:

Authorization: Bearer <your_jwt_token>
Content-Type: application/json

Request Format:

{
  "method": "tool_name",
  "params": {
    "parameter1": "value1",
    "parameter2": "value2"
  }
}

Examples

Get Channel Information

curl -X POST http://localhost:8000/mcp/v1/tools/invoke \
  -H "Authorization: Bearer YOUR_JWT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "method": "get_channel_info",
    "params": {
      "channel_id": "1234567890123456789"
    }
  }'

Send a Message

curl -X POST http://localhost:8000/mcp/v1/tools/invoke \
  -H "Authorization: Bearer YOUR_JWT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "method": "send_message",
    "params": {
      "channel_id": "1234567890123456789",
      "message": "Hello from MCP server!"
    }
  }'

Search Messages

curl -X POST http://localhost:8000/mcp/v1/tools/invoke \
  -H "Authorization: Bearer YOUR_JWT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "method": "search_messages",
    "params": {
      "channel_id": "1234567890123456789",
      "query": "hello",
      "limit": 10
    }
  }'

🧪 Testing

Use the provided test script to verify your setup:

# Update YOUR_DISCORD_TOKEN in test_server.py first
python test_server.py

📊 Monitoring and Logs

• Audit logs are written to audit.log
• Server logs are displayed in the console
• Each tool call is logged with user ID, parameters, and success/failure status

🏗️ Architecture

Authentication Flow

1. Token Generation: Discord token is embedded in JWT claims
2. Request Authentication: JWT is validated using RSA public key
3. Token Extraction: Discord token is extracted from validated JWT
4. Tool Execution: Temporary Discord bot connection is created
5. Cleanup: Bot connection is properly closed after operation

Security Benefits

• No token exposure: Discord tokens never appear in request parameters
• Centralized auth: Single authentication point for all tools
• Audit trail: Complete logging of all authenticated operations
• Temporary connections: No persistent bot instances reduce attack surface

🔒 Security Considerations

Development vs Production

• Development: Uses generated RSA key pairs (current setup)
• Production: Should use external OAuth 2.1 provider or IdP

Token Security

• JWT tokens expire after 1 hour (configurable)
• Discord tokens are embedded in JWT claims, not visible in requests
• RSA encryption ensures token integrity

Best Practices

1. Rotate tokens regularly in production
2. Use HTTPS for all communications
3. Store Discord tokens securely (environment variables, secrets manager)
4. Monitor audit logs for unusual activity
5. Implement rate limiting if needed

🤝 Integration with MCP Clients

This server follows the MCP specification and can be used with:

• Claude Desktop with MCP integration
• Custom MCP clients
• API testing tools (Postman, curl, etc.)

📚 References

• FastMCP Documentation
• FastMCP Bearer Token Auth
• Discord.py Documentation
• MCP Specification

🐛 Troubleshooting

Common Issues

1. "No Discord token found in authentication"

   • Verify your JWT token contains the Discord token in claims
   • Check token generation with correct Discord bot token

2. "Bot doesn't have permission"

   • Ensure Discord bot has necessary permissions in the server
   • Check channel permissions specifically

3. "Server not reachable"

   • Verify server is running on localhost:8000
   • Check for port conflicts

4. "Invalid token"

   • Token may be expired (1 hour default)
   • Generate a new token
   • Verify token format in Authorization header