openapi-to-mcp

npx skills add mcp-use/mcp-use --skill openapi-to-mcp --agent claude-code

Same command for any agent — swap --agent for codex, cursor, copilot.

# Build an MCP server from an OpenAPI spec Turn an existing REST API — described by an OpenAPI 3.x or Swagger 2.0 document — into an MCP server. Each operation in the spec becomes one MCP tool the LLM can call. The server runs locally for testing and ships to Manufact / mcp-use cloud with one command. This skill is the end-to-end recipe: scope → ingest spec → map operations → scaffold → generate tools → wire auth → test → deploy. ## Core philosophy: the spec is the contract The OpenAPI document is the source of truth. Tool names, descriptions, parameter shapes, and auth requirements all come from the spec — they should not be invented. This matters because: - **The LLM trusts descriptions.** If the spec says `summary: "Get current weather for a city"`, that's exactly what the LLM will read when deciding whether to call the tool. Hand-rolled summaries drift; spec-derived summaries stay in sync if the API changes. - **Zod schemas mirror OpenAPI schemas.** Every parameter — path, query, body — becomes a field in one zod object. Required/optional, enums, min/max, and descriptions all carry over. The LLM uses the schema to figure out what to ask the user for. - **Auth lives outside the

In the scaffolded project root
npm install @apidevtools/swagger-parser
Tools-only (the default for an OpenAPI wrapper)
npx create-mcp-use-app@latest <project-name> --template blank
Any widgets at all
npx create-mcp-use-app@latest <project-name> --template mcp-apps
cd <project-name>
npm install @apidevtools/swagger-parser dotenv
npm run dev
Save the dev server under a short name