"Using npx to run tools directly without requiring an API" matching MCP connectors:
GET /v1/connectors – MCP directory API referenceMatching Connector Tools:
Retrieve YouTube transcripts with timestamps, native captions and asynchronous generation when captions are unavailable. Requires a Capslane API key.
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
Point Gecko at an OpenAPI spec; get first-call-correct, auth-hidden agent tools.
Test HTTP 429/503 retries and Retry-After with server-observed traces; share synthetic findings.
Any API, four tools: discover, call with routing and signed receipts, verify, dispute.
{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"whoami","arguments":{}}} free no key
Guide developers from setup through a verified, policy-aware, audited Alter API call.
Turn any task into the right API calls: discover, evaluate, and integrate public APIs.
Your DRF API as MCP tools — 1,800 endpoints become 16 dispatchers, permissioned by Django.
SqueezeOS MCP for live machine discovery and x402-paid USDC APIs on Base.
chaos-index MCP — wraps StupidAPIs (requires X-API-Key)
ship-on-friday MCP — wraps StupidAPIs (requires X-API-Key)
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.
npm MCP — wraps the npm Registry API (free, no auth)
Verify an agent's advertised route, price, payment details, and schemas against its live endpoint.
yc-rejection MCP — wraps StupidAPIs (requires X-API-Key)
corporate-apology MCP — wraps StupidAPIs (requires X-API-Key)
Search the JoJ API marketplace, read endpoint docs, and call any API with one key via one gateway.
Ephemeral mailboxes and a mock OAuth IdP for testing email and auth flows — 39 API-driven tools covering mailboxes, mails, attachments, domains, teams, and mock identities.
