mcp-server-builder

MCP Server Builder

Scaffolds production-ready MCP servers from OpenAPI specs. Treats the API contract as the source of truth and generates tool manifests + starter code with quality gates before publication.

Description

Converts OpenAPI paths/operations into named MCP tool definitions, generates server scaffolds in Python or TypeScript, enforces naming and description quality, validates manifests against common production failures, and applies a versioning strategy for safe evolution. Distinct from mcp-cloudflare-builder (Cloudflare-specific deployment) and mcp-builder (general MCP concepts) — this skill is spec-driven and language-agnostic.

When to Use

• Exposing an internal or external REST API to LLM agents via MCP
• Replacing brittle browser automation with typed, validated tools
• Sharing one MCP server across multiple teams or assistants
• Bootstrapping from an existing OpenAPI spec rather than hand-writing tool definitions
• Running quality checks before publishing MCP tools to a registry

Workflow

Step 1: Parse the OpenAPI Spec

Read the spec and extract:

• Paths and HTTP methods
• operationId (use as canonical tool name when available)
• Request parameters and body schemas
• Response schemas
• Authentication requirements

Step 2: Generate Tool Manifest

For each operation, create an MCP tool definition:

{
  "name": "get_user",
  "description": "Retrieve a user by ID. Returns full profile including email and role.",
  "inputSchema": {
    "type": "object",
    "properties": {
      "user_id": { "type": "string", "description": "The user's UUID" }
    },
    "required": ["user_id"]
  }
}

Naming rules:

• Use operationId when available (preferred)
• Otherwise derive from method + path: GET /users/{id} → get_user
• Use snake_case; avoid raw path segments (get__v1__users___id is wrong)
• One intent per tool; avoid mega-tools combining unrelated operations

Description rules:

• Lead with action verb + object
• Include what the tool returns, not just what it does
• Note any side effects for mutating operations