The Givebutter API uses the standard HTTP status response codes:

400Bad Request: The request could not be understood by the server due to malformed syntax.
401Unauthorized: The request requires user authentication. The API access token may be missing or invalid.
403Forbidden: The server understood the request, but is refusing to fulfill it. The API user does not have correct permissions.
404Not Found: The resource requested does not exist or was not found.
405Method Not Allowed: The method / verb specified in the request is not allowed for the resource.
500Internal Server Error: The request was valid, but something failed on the server.