"Popular MCP tools commonly used by programmers" matching MCP connectors:
GET /v1/connectors – MCP directory API referenceMatching Connector Tools:
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.
Remote MCP that evaluates one public HTTPS URL for WebMCP readiness: intent, tools observed, what to add, what never to expose.
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
AI-callable tools for API mocking, testing, monitoring, security, and automation.
Point Gecko at an OpenAPI spec; get first-call-correct, auth-hidden agent tools.
Lints whether a paid API's 402 response speaks the x402 protocol correctly.
Apideck Unified API MCP — 330 tools across 200+ SaaS connectors (accounting, CRM, HRIS, ATS).
Research, inference, SEC filings, QR codes, digests, web/email tools and x402 service checks.
Free tools: x402 endpoint directory + probe, on-chain x402 demand signal, sudoku, API pricing.
Send and debug webhooks — applications, endpoints, messages, delivery attempts and replays.
Any API, four tools: discover, call with routing and signed receipts, verify, dispute.
Diagnoses whether an MCP server is reachable, by live HTTP probe.
Free agent tests (no account or payment); paid ping.
Check whether an MCP server answers, what its tools claim, and whether that claim has changed.
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.
{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"whoami","arguments":{}}} free no key
Your DRF API as MCP tools — 1,800 endpoints become 16 dispatchers, permissioned by Django.
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
An MCP server that provides tools to validate an email address using Dilli Email Validation API.
Swagger Petstore API (v1.0.27) as MCP for testing and prototyping powered by the HAPI MCP server
