"Free tools or resources that do not require an API" 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.
Contract-change authorization for AI agents: preflight a change to an API or MCP contract, get a signed decision, and verify the receipt offline. Only a granted change can proceed.
Traffic Parrot simulates APIs and messaging. Request or withdraw a trial, read docs, send feedback.
Scores how well AI agents will use your API, 0-100, from its OpenAPI spec. Free and read-only.
Test and debug your AI agent's Web Bot Auth (RFC 9421) signature: is it valid, and what to fix?
Signed declarations of HTTP API exchanges for agent handoffs. Free preparation and verification; receipt issuance costs 0.002 USDC via x402 on Base. Start and connect: https://datoka.dev/api. Signatures attest declared data, not independent truth.
Remote MCP that evaluates one public HTTPS URL for WebMCP readiness: intent, tools observed, what to add, what never to expose.
Webhook, email, WebSocket and tunnel testing for AI agents: capture, wait, verify, replay.
GXEON services, prepaid packs from R$0.99, purchase planning, and agent buyer guidance.
Retrieve YouTube transcripts with timestamps, native captions and asynchronous generation when captions are unavailable. Requires a Capslane API key.
AI-Powered Java/Spring Boot code review API with Alipay AI Pay support.
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
API documentation drifts away from the running service, so consumers integrate against a contract nobody keeps. Routebase keeps API design, testing, mocking and documentation on one living source of truth, and this MCP server exposes that workspace to AI agents. Agents can design endpoints, write and run test suites, manage mock servers and publish documentation, always under the permissions of the connected Routebase account.
Independent health, price and history for x402/MPP endpoints. Metered over x402; free grade on web.
Detect breaking changes, generate changelogs, diff, and validate OpenAPI specs.
Free tools: x402 endpoint directory + probe, on-chain x402 demand signal, sudoku, API pricing.
AI-callable tools for API mocking, testing, monitoring, security, and automation.
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.
Point Gecko at an OpenAPI spec; get first-call-correct, auth-hidden agent tools.
Is this x402/MPP API safe to pay? $0.001 go/no-go preflight, diagnosis and fixes. Free quick check.
