Errors
Error format
Errors return a JSON body:
code
{ "error": "human-readable message" }Status codes
Status codes for POST /v1/payment-links:
| Status | Meaning |
|---|---|
| 400 | Invalid request — malformed JSON, or missing/invalid amount |
| 401 | Missing or invalid API key |
| 500 | Internal error (including an upstream PSP failure) — safe to retry |
Webhook responses
Inbound webhook processing (/webhooks/mollie) returns 200 on success, duplicate, or
unknown; 400 on a missing id; and 500 on a transient error (which we retry).