"Free PostgreSQL Database Solutions" 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.
Generate structurally valid test IBANs for 91 countries (MOD-97 and national check digits), validate any IBAN and export lists. Free, no sign-up.
Validate and clean CSV before import. Find duplicates, missing values and invalid dates with row-level reports. Apply only the cleanup you request; files are not retained. Run view_csv_demo free without a key. Custom CSV: EUR 9 for 100 operations, valid 90 days, no subscription. Setup: https://check.orvel.dev/docs/
Lint a SKILL.md for frontmatter, structure, secrets and size. All 6 tools free.
Free AI test helpers: injection inputs, OWASP mapping, release plans, response and tool-call packs.
Diagnose why an AI agent failed and get the verified fix instantly. Free, no token.
Validate CSV columns, find duplicates and invalid values, and clean files with explicit rules. Row-level reports, no stored files. Run the fixed free sample without a key. Custom CSV: EUR 9 for 100 operations, valid 90 days, no subscription. Setup: https://import-check-production.up.railway.app/docs/
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.
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
Free WCAG 2.2/ADA/508 accessibility MCP: scan, AI fixes, verify, vision audit, localhost tunnel
Checks a public website in six areas and returns scores from 0 to 100. Free, no key needed.
Does an MCP server work for a stock client? By registry name or URL. Tool drift too. Free, no key.
Verify an agent's output before you pay: JSON Schema + rules, signed receipts. Free during launch.
Free MCP, API auth, webhook and schema diagnostics with bounded checks and safe quote routing.
Free, no-key, read-only MCP endpoint verification and diagnostics.
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.
Verify claims, citations & agent actions. Free receipt trial; paid prices via live R/IV quotes.
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.
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 tools: 2026 API shutdown scanner, small-business website auditor, photo resale estimator.
