"Free Network Graph Visualization Tools (No Account Required)" 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.
Read one operation from a public OpenAPI document: method, path, and required fields.
Read-only MCP server for querying OkkMax measurements of AI API relay services, including model availability, observed prices, 24-hour uptime, latency, and model- and group-level purity evidence. No sign-in or API key is required.
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.
Independent static checks for supported tag and alarm CSV import formats; no HMI or PLC access.
Audits any URL for HTTP 402 x402 V2 compliance, PAYMENT-REQUIRED headers, Bazaar schema, and MCP.
Is this x402/MPP API safe to pay? $0.001 preflight, fixes, a $0.25 test purchase. Free quick check.
Scores how well AI agents will use your API, 0-100, from its OpenAPI spec. Free and read-only.
Remote MCP that evaluates one public HTTPS URL for WebMCP readiness: intent, tools observed, what to add, what never to expose.
Annotation-survival conformance for MCP tools. Receipt $0.01, check $4.99, plans $9.99/$19.99.
Free *.pntr.dev dev subdomains — register subdomains, manage DNS and wildcard records, receive email on disposable inboxes, and capture HTTP requests for webhook debugging. OAuth sign-in; free tier.
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.
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.
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.
AI-callable tools for API mocking, testing, monitoring, security, and automation.
imonfhir.com tools: HL7 digest, Jira status, PAS validation, IG and payload compare, rule evidence.
Apideck Unified API MCP — 330 tools across 200+ SaaS connectors (accounting, CRM, HRIS, ATS).
Email inboxes, webhook URLs, mock APIs and 170+ tools for coding agents over one MCP connection.
Email, webhooks, mocks and 170 tools for AI coding agents, over one MCP connection.
Web/PDF extraction and API comparison. x402 payments or prepaid comparison credit. Free discovery.
Point Gecko at an OpenAPI spec; get first-call-correct, auth-hidden agent tools.
Free x402 endpoint linter: unpaid 402 challenge, payTo/asset/amount, CORS, directory readiness.
Trickl for AI assistants: full docs, setup plans, and sandbox tools to test purchases end to end.
Search and read the Flowie Exchange API docs and OpenAPI contract. No sign-in needed.
Research, inference, data/web/email tools, and x402 conformance, service catalog and grade feeds.
Lints whether a paid API's 402 response speaks the x402 protocol correctly.
Read-only MCP server checks and quote verification, free and keyless; results signed and publicly lo
Your DRF API as MCP tools — 1,800 endpoints become 16 dispatchers, permissioned by Django.
Free tools: x402 endpoint directory + probe, on-chain x402 demand signal, sudoku, API pricing.
Test any x402 paid URL without paying: 402, PAYMENT-REQUIRED, USDC, amounts, payTo, EIP-712, CORS.
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.
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
MCP tool observatory: do registry servers answer, and are their answers true? No key.
Test FIX from Claude, ChatGPT, or Cursor: free sandbox FIX sessions or your own FIXSIM instances.
