YouTube Transcript API Error Codes
| Status | Code | Description |
|---|---|---|
| 400 | invalid-request | Missing or invalid URL/videoId |
| 206 | transcript-unavailable | No transcript available for video |
| 401 | unauthorized | Invalid or missing API key |
| 404 | not-found | Video not found (is private, deleted, etc.) |
| 500 | error | Generic error with message |