"Simple HTTP server or client implementation" matching MCP connectors:
GET /v1/connectors – MCP directory API referenceMatching Connector Tools:
Check an A2A agent before you delegate, or an MCP server's measured conduct. Free, no key.
Contract-change authorization for AI agents: preflight a change to an API or MCP contract, get a signed decision, and verify the receipt offline. Only a granted change can proceed.
Traffic Parrot simulates APIs and messaging. Request or withdraw a trial, read docs, send feedback.
Signed declarations of HTTP API exchanges for agent handoffs. Free preparation and verification; receipt issuance costs 0.002 USDC via x402 on Base. Start and connect: https://datoka.dev/api. Signatures attest declared data, not independent truth.
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
API documentation drifts away from the running service, so consumers integrate against a contract nobody keeps. Routebase keeps API design, testing, mocking and documentation on one living source of truth, and this MCP server exposes that workspace to AI agents. Agents can design endpoints, write and run test suites, manage mock servers and publish documentation, always under the permissions of the connected Routebase account.
Free *.pntr.dev dev subdomains — register subdomains, manage DNS and wildcard records, receive email on disposable inboxes, and capture HTTP requests for webhook debugging. OAuth sign-in; free tier.
AI-callable tools for API mocking, testing, monitoring, security, and automation.
Free tools: x402 endpoint directory + probe, on-chain x402 demand signal, sudoku, API pricing.
Inspect external HTTPS 429/503 retries with server-recorded attempts, Retry-After and arrival times.
What is known to be broken in an MCP server or API operation, with the check that found it.
Diagnoses whether an MCP server is reachable, by live HTTP probe.
Free agent tests (no account or payment); paid ping.
Point Claude Code, Qwen Code, Cursor, or any MCP client at https://docs.jmeter.ai/api/mcp and your agent answers JMeter questions grounded in this documentation, with a source link for every answer. Free, no API key, no signup.
Audits a sample of HTTP request URLs against explicit, documented cache-key standardization rules...
Check whether an MCP server answers, what its tools claim, and whether that claim has changed.
Experimental MCP server for current empirical verification of explicit public HTTPS endpoint claims.
Test FIX from Claude, ChatGPT, or Cursor: free sandbox FIX sessions or your own FIXSIM instances.
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
ACAO star-or-origin, value discarded