# Errors

Failures use `application/problem+json` following RFC 9457:

```json
{"type":"https://scrape.it/problems/proxy-auth-failed","title":"Proxy authentication failed","status":422,"detail":"The selected proxy connector rejected its credentials.","requestId":"req_example"}
```

Problem documents never include raw secrets, internal hostnames, stack traces, or database errors. Authentication is in the `Authorization` header only. A repeated asynchronous request with the same account, key, idempotency value, and equivalent body returns the original job; a conflicting body returns 409.