"Home Assistant integration with Codex or ChatGPT" 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.
Developer checks and Agent Observatory: A2A, MCP and OpenAPI checks with a dated change log.
Retrieve YouTube transcripts with timestamps, native captions and asynchronous generation when captions are unavailable. Requires a Capslane API key.
AI-Powered Java/Spring Boot code review API with Alipay AI Pay support.
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
Deterministic JSON checks with signed evidence and x402-paid execution
Discovery registry for AI agents: 660+ APIs, MCP servers and CLIs, each health-checked every 6 hours with real requests — full initialize + tools/list handshakes for MCP, real calls for APIs — plus response-schema validation that catches responses which parse fine but are missing a required field.
Inspect external HTTPS 429/503 retries with server-recorded attempts, Retry-After and arrival times.
Sanctions API docs and request validation, with account-linked synthetic sandbox testing.
Free MCP, API auth, webhook and schema diagnostics with bounded checks and safe quote routing.
Any API, four tools: discover, call with routing and signed receipts, verify, dispute.
What is known to be broken in an MCP server or API operation, with the check that found it.
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.
MYCELIX agent research and read-only MCP verification with verify_mcp_endpoint.
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
Search the JoJ API marketplace, read endpoint docs, and call any API with one key via one gateway.
ACAO star-or-origin, value discarded
