Roughly 45% of failed paid calls in this fleet fail on malformed input — a missing field, a number where a string belongs — and the buyer only finds out after the payment settles. This free check flips that around: pick an endpoint, paste the exact input you are about to send, and get every shape error up front, each with the fix and a corrected example. Nothing is executed against the paid endpoint; no payment is involved.
The validator only uses what the endpoint itself publishes, and the result names the source: the endpoint's own OpenAPI properties/parameters where it declares them; otherwise the fleet catalogue's input-field list for that endpoint; otherwise the endpoint spec's own "Input:" line. Some endpoints publish no machine-readable schema at all — for those you get an explicit schema unavailable answer instead of a made-up one. A pass means your input satisfies every declared requirement; it is a shape check, not a guarantee the endpoint will accept the values semantically.
POST https://api.mekongtradeintel.com/clinic/validate-input
{ "slug": "enrich", "input": { "domain": "example.com" } }
→ { "ok": true, "slug": "enrich", "valid": true, "errors": [], "price_usd": 0.02, "schema_tier": "openapi", ... }
→ invalid input: "valid": false, "errors": [ { "field": "domain", "issue": "missing required field", "expected": ..., "received": "(missing)", "fix": ..., "example": ... } ]
→ no published schema: "valid": null, "schema_available": false
→ unknown slug: HTTP 404 · missing slug / non-object input: HTTP 400
Already paid and got an error back? The 402 clinic explains trial-vs-paid differences and payment failures. Not sure your wallet can pay at all? Run the wallet-health pre-check.