# session-invalid

`https://ckrets.ai/problems/session-invalid` is a problem type of the ckrets.ai API (RFC 9457: the body is
`application/problem+json` with `type`, `title`, `status` and `detail`; every problem from `/v1` also carries `requestId`).

| Status | Also in the answer | What to do |
|---|---|---|
| 401 | - | an anonymous puzzle create needs a session ticket: `POST /v1/sessions` with a Turnstile token, then send `Ckrets-Proof: session=<ticket>` |

Every type, with its retry rule and headers: [limits.md, "Errors, retries and headers"](/limits.md#errors-retries-and-headers).