Error Handling

Handle errors at both the API layer and transaction-result layer.

API errors

HTTP status	Meaning	Recommended action
`400`	Validation or processing error.	Fix request fields and retry only after correcting the payload.
`401`	Missing or invalid API key.	Confirm the `X-Api-Key` header.
`403`	Account or permission issue.	Contact your account manager.
`500`	Processing-side error.	Retry later or contact support if it persists.

A processor decline may be returned inside a successful HTTP response.

If the API returns HTTP 200 but response_code is 200, treat the transaction as declined.

{
  "order_id": "700202",
  "response_code": 200,
  "gateway_response_code": "202",
  "gateway_response_description": "Insufficient funds"
}

Postback delivery fails when your endpoint does not return HTTP 200.

Common causes:

Cause	Fix
Endpoint returns `401` or `403`	Allow the postback request or adjust endpoint authentication.
Endpoint returns `404`	Confirm the configured Postback URL.
Endpoint returns `500`	Check your server logs.
Timeout	Return HTTP `200` quickly, then process complex work asynchronously.
Invalid SSL	Use a valid HTTPS certificate.

Review delivery attempts here: