YouTube Transcript API Error Codes
| Status | Code | Description |
|---|---|---|
| 400 | invalid-request | Missing or invalid URL/videoId |
| 206 | transcript-unavailable | No transcript available for video |
| 403 | invalid-request | Invalid or missing API key |
| 404 | not-found | Video/playlist/channel not found (or is private, deleted etc.) |
| 429 | limit-exceeded | Too many requests or quota exceeded |
| 500 | error | Generic error with message |