"Wikipedia - The Free Online Encyclopedia" matching MCP connectors:

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

Check that your AI is being logical. Free tool that mathematically catches contradictions in agent reasoning. No account needed. Also offers paid guardrails that converts natural language to formal verification proofs, that anyone can check succinctly.

Estimated game fps for any GPU or Apple Silicon chip, with the limiter and tweaks.

Check if your MCP server is ready to publish on the MCP Registry, Smithery, or npm.

Grade MCP servers A to F with the open behavioral litmus. npm: full toolset; hosted: lookups only.

Runs your code against a contract; returns HELD or BROKE at the exact input. Deterministic.

Test the voice agents you run: scored transcripts, pass/fail verdicts, latency and WER metrics.

Generate realistic relational test data — 156 field types, 22 locales, JSON/CSV/SQL, free previews.

Read-only MCP server for the OPERANT AI operating-agent calibration benchmark.

MCP server for the Fail Modes taxonomy — a knowledge base of AI system failure modes

Multi-Agent AI Validation: X-Z-CS Trinity. 13 tools FREE. Auditable reasoning. v0.5.54

PQS scores any prompt before the model runs. 8 dimensions. 5 frameworks. Pre-flight, not post-hoc.

Pay-per-call MCP server. Vetted human experts review AI-generated content (text, images, video, audio, social posts), audit reasoning chains, run prepublish safety checks, and gate high-stakes actions for human approval. 7 paid tools at $1.00 each plus 4 free tools (list_offerings, list_expert_profiles, get_result, verify_certificate). Payment via x402, USDC on Base mainnet. Approved outputs receive an on-chain Taste content certificate downstream agents verify before consuming.

130+ QA & dev tools for AI agents: prompt injection, RAG testing, VLM eval, guardrails. Free.

The world's first named AI prompt quality score. Score, optimize, and compare LLM prompts before they hit any model. Free tier available. Built on PEEM, RAGAS, G-Eval, and MT-Bench frameworks. x402-native on Base.

Test-inbox API for email and SMS: create inboxes, long-poll messages, extract OTPs and links. 34 tools; bearer auth with an mfx_ API key (free tier).

MCP server providing access to the Scorecard API to evaluate and optimize LLM systems.

Check AI work against requirements and return structured verdicts, findings, and repair steps.

Programmatic email deliverability testing for AI agents. Create inbox placement tests across Gmail, Outlook, Yahoo, Mail.ru, Yandex — get per-provider placement (Inbox/Spam/Promotions), SPF/DKIM/DMARC auth, Rspamd & SpamAssassin verdicts, DNS health, and live SSE results.

Scores any MCP server before you trust it: free quick check, full paid report, 2-5 way compare.