[Sendbird docs, Chat Platform API error codes]: Read the detail code, not just the HTTP status. 400920 covers several distinct cases: RequestDenied (API call from an unauthorized IP), ReadOnlyMode (app is in read-only mode so only GETs work), NotAccessible (push is off in the app, invalid announcement parameter, or deleting a message that has a child message). 403100 ApplicationNotAvailable means the application identified by the request is not available. 500910 RateLimitExceeded on a 429 means you exceeded rate limits; 500901 InternalError and 500601/500602 push-token errors are retryable, and 503 ServiceUnavailable is temporary so retry.

Context: Sendbird Platform API calls fail with numeric error codes like 400920, 403100, or 500910 instead of plain HTTP statuses.