develop-mcp-server

description: Boilerplate Instructions to develop MCP Servers. globs: alwaysApply: false

MCP Plugin Development Protocol

⚠️ CRITICAL: DO NOT USE attempt_completion BEFORE TESTING ⚠️

Step 1: Planning (PLAN MODE)

• What problem does this tool solve?
• What API/service will it use?
• What are the authentication requirements? □ Standard API key □ OAuth (requires separate setup script) □ Other credentials

Step 2: Implementation (ACT MODE)

1. Bootstrap

   • For web services, JavaScript integration, or Node.js environments:

     npx @modelcontextprotocol/create-server my-server
     cd my-server
     npm install
     

   • For data science, ML workflows, or Python environments:

     pip install mcp
     # Or with uv (recommended)
     uv add "mcp[cli]"
     

2. Core Implementation

   • Use MCP SDK
   • Implement comprehensive logging
     • TypeScript (for web/JS projects):

       console.error('[Setup] Initializing server...');
       console.error('[API] Request to endpoint:', endpoint);
       console.error('[Error] Failed with:', error);
       

     • Python (for data science/ML projects):

       import logging
       logging.error('[Setup] Initializing server...')
       logging.error(f'[API] Request to endpoint: {endpoint}')
       logging.error(f'[Error] Failed with: {str(error)}')
       

   • Add type definitions
   • Handle errors with context
   • Implement rate limiting if needed

3. Configuration

   • Get credentials from user if needed
   • Add to MCP settings:
     • For TypeScript projects:

       {
         "mcpServers": {
           "my-server": {
             "command": "node",
             "args": ["path/to/build/index.js"],
             "env": {
               "API_KEY": "key"
             },
             "disabled": false,
             "autoApprove": []
           }
         }
       }
       

     • For Python projects:

       # Directly with command line
       mcp install server.py -v API_KEY=key
       
       # Or in settings.json
       {
         "mcpServers": {
           "my-server": {
             "command": "python",
             "args": ["server.py"],
             "env": {
               "API_KEY": "key"
             },
             "disabled": false,
             "autoApprove": []
           }
         }
       }