MCP Builder

Use this skill when the user asks to create, configure, or debug an MCP server or tool integration.

Design Rules

• Prefer stdio MCP servers for local tools and HTTP/SSE for remote services.
• Keep tool schemas small, typed, and explicit. Return structured JSON where possible.
• Put secrets in environment variables, never in committed config.
• For HTTP/SSE clients, send Accept: application/json, text/event-stream by default unless the server explicitly requires something else.
• Add timeouts and clear error messages around external APIs.

Codewhale Setup

Common commands:

codewhale mcp init
codewhale mcp add my-server --command node --arg server.js
codewhale mcp add remote-server --url http://127.0.0.1:3000/mcp
codewhale mcp list
codewhale mcp validate
codewhale mcp tools

HTTP/SSE entries can include per-server headers in ~/.codewhale/mcp.json when credentials or custom routing headers are required.

Workflow

1. Define the service boundary and the minimum useful tools.
2. Choose transport and credential handling.
3. Implement the server using a maintained MCP SDK when available.
4. Add the server with codewhale mcp add or edit ~/.codewhale/mcp.json.
5. Run codewhale mcp validate, then codewhale mcp tools.
6. Test one happy path and one failure path before calling it done.