"Local and free services or resources" matching MCP connectors:
Matching Connector Tools:
Detect breaking changes, generate changelogs, diff, and validate OpenAPI specs.
Free platform to test MCP clients without installing anything. Create mock tools with dynamic templates, configurable delays, conditions (if/then), and response sequences. Supports JSON-RPC 2.0 over Streamable HTTP. Built-in text_echo and json_echo tools. Rate-limited tiers: anonymous (5 calls/min, 1 mock tool), registered (10 calls/min, 4 mock tools), premium (60 calls/min, unlimited). Zero setup — no install, no registration required. More info: https://www.testmcp.dev
MCP tool observatory: do registry servers answer, and are their answers true? No key.
A webhook inbox for agents: one call returns a live URL. Mock, verify, inspect and replay.
Deterministic JSON checks with signed evidence and x402-paid execution
Deploy production REST APIs from JSON schemas in seconds. Manage projects, schemas, and deployments.
Discover, pay for, execute, and publish APIs through Apiosk.
Check an MCP endpoint resolves: liveness, live tool list, schema drift. Free.
Anonymous webhook capture, inspection, waiting, and response configuration for AI agents.
JSONPlaceholder MCP — wraps JSONPlaceholder fake REST API (free, no auth)
Create hosted mock REST APIs as tools: seed fake data, import specs, query, write, snapshot. Free.
Instant no-signup webhook & HTTP-request inspector for testing webhooks and agent tool-callbacks.
Verify x402 endpoints before payment or publish service profiles for agent discovery.
Keyless webhook endpoints: capture, wait, replay, forward, and generate types from real traffic.
Debug webhooks from your AI agent: inspect and replay captured webhooks on localhost.
End-to-end API testing — generate and run tests from OpenAPI, curl, Postman, or real user traffic.
Swagger Petstore API (v1.0.27) as MCP for testing and prototyping powered by the HAPI MCP server
40+ developer tools from Context7, Code Runner, Python Execute, NPM Sentinel, PlantUML, and Microsoft Learn. Docs lookup, code execution, security scanning. Starts at $0.01/call. Get your API key at app.xpay.sh or xpay.tools
Public benchmark where agents submit Q&A answers and get scored on a leaderboard.