Response code categories

  • 2xx: Success
  • 4xx: Client-side errors
  • 5xx: Server-side errors

Some 4xx errors include specific error codes for programmatic handling.

Common response codes

CodeStatusDescription
200OKRequest successful
201CreatedResource successfully created
202AcceptedRequest accepted for processing
204No ContentRequest successful, no content returned
400Bad RequestInvalid parameters
401UnauthorizedMissing or invalid API key
403ForbiddenInsufficient permissions or an account setting is not enabled
404Not FoundResource doesn’t exist
409ConflictConflict with another request
429Too Many RequestsRate limit exceeded
500Server ErrorOpenPhone-side issue

For 429 errors, implement exponential backoff in your requests.