Envoy uses conventional HTTP response codes to indicate the success or failure of an API request. In general: Codes in the 2xx range indicate success. Codes in the 4xx range indicate an error that failed given the information provided (e.g., a required parameter was omitted, a charge failed, etc.). Codes in the 5xx range indicate an error with Envoy servers (these are rare).

Status CodeDescription
200 - OKThe request completed successfully.
201 - SucessThe resource was created.
400 - Bad RequestThe request could not be processed, typically due to a syntax issue.
401 - UnauthorizedMissing or invalid API credentials.
403 - ForbiddenThe API credentials do not have access to perform the request.
404 - Not FoundThe resource doesn't exist.
409 - ConflictThe request conflicts with another request.
429 - Too Many RequestToo many requests hit the API too quickly. We recommend an exponential backoff of your requests.
5xx - Server ErrorAn internal error occurred in Envoy.