parameter_unknown
HTTP 422, type invalid_request_error.
The request body carried a field this endpoint does not define.
Why it happened
Unknown fields are rejected rather than ignored. Silently dropping a field is how a typo in a field name becomes a payment that behaves differently from the one you thought you sent, and you would not find out until you reconciled.
The param in the error names the field we did not recognise.
How to fix it
Remove the field, or correct its spelling.
{ "error": { "code": "parameter_unknown", "param": "descriptor" } }
If you meant to attach your own data, use metadata, which takes arbitrary keys by design, on the requests that accept it: creating a payment, a checkout session, a customer, a saved card, a plan or a subscription, and updating a customer, a plan or a subscription. Captures, voids, refunds, cancellations, pauses and resumes take no metadata.
Retrying: retry only after fixing the request, by removing the field named in param. This request is refused before its Idempotency-Key is claimed, so send the corrected request with the same Idempotency-Key.
Related codes
parameter_missing-- a required field absentamount_invalid_type-- a known field with the wrong type