"How to Read an Excel File" 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

Conformance checker for MCP servers. Free, no key, verdicts recomputable and re-measured daily.

Point Gecko at an OpenAPI spec; get first-call-correct, auth-hidden agent tools.

ship-on-friday MCP — wraps StupidAPIs (requires X-API-Key)

chaos-index MCP — wraps StupidAPIs (requires X-API-Key)

schrodingers-boolean MCP — wraps StupidAPIs (requires X-API-Key)

JSON Schema validation MCP.

always-seven MCP — wraps StupidAPIs (requires X-API-Key)

Check an MCP endpoint resolves: liveness, live tool list, schema drift. Free.

the-committee MCP — wraps StupidAPIs (requires X-API-Key)

passive-aggression MCP — wraps StupidAPIs (requires X-API-Key)

mercury-number MCP — wraps StupidAPIs (requires X-API-Key)

excuse MCP — wraps StupidAPIs (requires X-API-Key)

corporate-apology MCP — wraps StupidAPIs (requires X-API-Key)

JSONPlaceholder MCP — wraps JSONPlaceholder fake REST API (free, no auth)

apology MCP — wraps StupidAPIs (requires X-API-Key)

yc-rejection MCP — wraps StupidAPIs (requires X-API-Key)

victorian-complaint MCP — wraps StupidAPIs (requires X-API-Key)

httpbin echo: GET/POST inspection, status codes, delay, UUID, base64. Debug aid.

DummyJSON mock REST: products, users, posts, recipes, todos. Keyless test data.