Name: Nuvlyx
Rating: 4.9 (124 reviews)

Error response format

All error responses share the same JSON body regardless of the endpoint:

{
  "statusCode": 403,
  "message": "This token is missing the required scopes: orders:write",
  "error": "Forbidden"
}

For validation failures (422), message may be an array of strings, one per invalid field.

HTTP codes returned by the API

Code	Meaning	Retry?
`200`	Success.	—
`201`	Resource created.	—
`400`	Bad request or business rule violated (e.g. insufficient balance).	No (fix first).
`401`	Token missing, malformed, revoked or expired.	No (regenerate token).
`403`	Token valid but missing scope for the route.	No (add scope).
`404`	Resource not found in your store.	No.
`409`	Conflict (e.g. duplicate webhook URL).	No.
`422`	Validation failed (missing field, invalid format).	No (fix the body).
`429`	Rate limit exceeded (see rate limits).	Yes, with backoff.
`500`	Internal error.	Yes, with exponential backoff.
`502 / 503 / 504`	Service temporarily unavailable.	Yes, with exponential backoff.

4xx: do not retry. Fix the request first.
429: honor the Retry-After header if present, otherwise exponential backoff starting at 1 s.
5xx: exponential backoff — 1 s, 2 s, 4 s, 8 s, 16 s — max 5 attempts.
Use Idempotency-Key on order and recharge creates to avoid duplicates on retries.