"Finding MCP Servers with F Security Grades" matching MCP connectors:
GET /v1/connectors – MCP directory API referenceMatching Connector Tools:
Serverless 15-tool B2B email deliverability, domain security, OpenAPI breaking-change release gate, LLMO /llms.txt auditor, and quantitative trading risk MCP connector.
Behind Check and GAIP Watch, and Diagnose: A2A, MCP and OpenAPI checks with a dated change log.
Write, check, render and save sequence diagrams with the request and response on every arrow.
Simceptor is an AI-native Mock API simulation platform with a built-in MCP server. It enables AI agents to create, inspect, update, and test dynamic mock APIs, conditional response rules, stateful session simulations, and network latency directly from context.
x402 endpoint doctor: grades a paid route A-F unpaid, with paste-ready fixes. By Crypto Money Maker
Grade MCP tool definitions for agent-readiness: score, A-F grade, fixes, est. token cost.
Turn any public webpage into JSON with AI, save it as a live JSON API, and call it from your agent.
Parallel-burst abuse testing for agent APIs with replayable evidence packs.
Live-payload conformance probes with signed receipts: ABSENT/EMPTY/PARTIAL/COMPLETE/BROKEN.
Retrieve YouTube transcripts with timestamps, native captions and asynchronous generation when captions are unavailable. Requires a Capslane 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.
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-Powered Java/Spring Boot code review API with Alipay AI Pay support.
Deterministic JSON checks with signed evidence and x402-paid execution
AI-callable tools for API mocking, testing, monitoring, security, and automation.
Inspect external HTTPS 429/503 retries with server-recorded attempts, Retry-After and arrival times.
Hosted MCP infrastructure with seven typed tools: JSON repair, JSON Schema validation, JSON to TypeScript, CSV to JSON, JSON to CSV, OpenAPI security and webhook checks. Public tool discovery; execution uses scoped Bearer keys with tool allowlists, quotas and request IDs. Free deterministic calls, no LLM calls or USDC payments. Runnable repair → validate → CSV example: https://invokeport.com/agents/workflows/json-pipeline. MCP through 2025-11-25; custom headers, no OAuth.
What is known to be broken in an MCP server or API operation, with the check that found it.
Any API, four tools: discover, call with routing and signed receipts, verify, dispute.
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.
Search the JoJ API marketplace, read endpoint docs, and call any API with one key via one gateway.
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
HttpStatus MCP Server — 24 AI-callable tools for API testing, mocking, monitoring, and security. Create and manage API mocks, run chaos engineering rules, validate OpenAPI specs, scan URLs for security issues, check SSL certificates, debug CORS, analyze redirect chains, decode JWTs, inspect HAR files, trace distributed requests, capture webhooks, build automation workflows (including Postman import), and set up uptime monitors — all from your AI assistant.
Find and call verified APIs from any AI assistant, with free trial calls and previewed writes.
AI-operated. All tools paid: an unpaid tools/call answers HTTP 402 with x402 terms, USDC on Base.
AI-native mock API server with MCP. Create REST/SOAP mocks from Claude, Cursor, or Windsurf.
Search millions of x402 APIs for data, finance, validation, security, inventory, sync and automation
Validated API and app vulnerability findings with remediation guidance.
Deterministic JSON Schema validation with exact violations and conservative type normalization.