| 400 | invalid_request | Body missing or malformed | Check the fields named in message |
| 401 | invalid_api_key | Key missing, wrong type, or revoked | Use the right key (sk_ vs pk_), check it wasn't revoked |
| 401 | invalid_session | Chat session expired or revoked | Create a new session (the widget does this) |
| 402 | plan_inactive | The client's plan isn't active | Start or renew the plan in the dashboard |
| 403 | browser_request | Secret key used from a browser | Move the call to your server |
| 403 | origin_not_allowed | Page origin isn't on Allowed sites | Add the exact origin, including https:// and subdomain |
| 403 | anonymous_disabled | Anonymous chat is off | Turn it on, or use signed-in sessions |
| 403 | unavailable | Persona not set up or plan inactive | Finish setup in the dashboard |
| 429 | rate_limited | Too many anonymous sessions | Back off; see limits below |
| 429 | (chat) | Monthly reply allowance used up | Shown to the user as "check back soon" |