openapi-mcp-server

A production-oriented TypeScript library and runtime that converts OpenAPI documents into MCP services.

Features

• Tools generated from OpenAPI operations

• Prompts generated from API metadata and operations

• Resources generated from the OpenAPI catalog

• HTTP and STDIO MCP transports

• Admin Web UI

• Persistent runtime state

• Stronger validation and safer request execution

• Production-oriented structure for future SaaS evolution

Related MCP server: OpenMCP

Install

npm install

Build

npm run build

Start web runtime

npm run start -- serve --port 3000 --host 127.0.0.1

Start STDIO runtime

node dist/cli.js serve --transport stdio --spec ./openapi.yaml

Demo

npm run demo

Library usage

import {
  parseSpecContent,
  generateTools,
  generatePrompts,
  generateResources,
  buildMcpServer,
} from "openapi-mcp-production";

CLI usage

Web mode

openapi-mcp serve \
  --transport web \
  --port 3000 \
  --host 127.0.0.1 \
  --api-key your-admin-key

STDIO mode

openapi-mcp serve \
  --transport stdio \
  --spec ./openapi.yaml \
  --base-url https://api.example.com

Production notes

This version is production-oriented, but you should still add the following for SaaS deployment:

• tenant isolation

• database-backed project registry

• rate limits

• audit logs

• RBAC

• secure secret storage

• upstream host allowlists

• comprehensive test suites

• full OpenAPI parameter serialization coverage

• full requestBody content negotiation support

Project structure

• src/core: spec parsing, operation traversal, tool generation, request building, execution

• src/mcp: MCP server creation and transports

• src/registry: prompts and resources registries

• src/runtime: runtime service registry

• src/server: admin HTTP server

• src/webui: browser UI

• src/config: persistence helpers

Web UI

The UI supports:

• upload and paste OpenAPI documents

• view tools, prompts, and resources

• inspect runtime services

• stop services

• basic MCP debugging hints

• SSE endpoint discovery

• STDIO tooltip guidance

Important implementation policy

All source comments are written in American English.