API Development MCP Servers

Swagger Petstore API (v1.0.27) as MCP for testing and prototyping powered by the HAPI MCP server

JSONPlaceholder MCP — wraps JSONPlaceholder fake REST API (free, no auth)

Range bytes start-end shape, value discarded

Send and receive webhooks, manage customer endpoints, and inspect and retry deliveries.

Retry-After integer-or-date, value discarded

MCP server for secureFlows: token-free URL builders and integration-linting tools for AI agents.

AI-native mock API server with MCP. Create REST/SOAP mocks from Claude, Cursor, or Windsurf.

SSE Accept hint

Send and debug webhooks — applications, endpoints, messages, delivery attempts and replays.

Spring Boot example that exposes SpringDoc OpenAPI operations as safe MCP tools.

Production proofs for breaking JSON Schema/MCP changes; UNKNOWN/NO_WITNESS_FOUND not compatible.

Traffic Parrot simulates APIs and messaging. Request or withdraw a trial, read docs, send feedback.

Keyless webhook endpoints: capture, wait, replay, forward, and generate types from real traffic.

Anonymous webhook capture, inspection, waiting, and response configuration for AI agents.

Discover and call 10,000+ production APIs from one MCP server. Pay-per-call billing for AI agents.

Cloudflare Workers MCP server: api-contract-validator

Sixteen years of API research as MCP tools — stories, areas, governance blocks & services

Cloudflare Workers MCP server: api-mock-server

Cloudflare Workers MCP server: api-response-cost-analyzer

Cloudflare Workers MCP server: api-schema-drift-detector

Discover, rate and compare APIs and providers in the APIs.io catalog; manage a listing you own.