mcp-builder — Building Production-Grade MCP Servers

Size budget: 25 KB. Check: wc -c. Gate: node ~/.claude/scripts/token-budget.mjs --check

Principal-level guide for authoring MCP servers. Auto-fires when work touches mcp-server/**, mcp_servers/**, *.mcp.json, files importing @modelcontextprotocol/sdk (TypeScript) or mcp / fastmcp (Python), or any task described as "build an MCP server / MCP tool / MCP integration".

Reference map

The detail lives in references/, loaded only when the topic is needed. Read the row that matches the task rather than the whole directory.