> ## Documentation Index
> Fetch the complete documentation index at: https://cortex-foundation-add13747-droid-1a2462c9-cor-444-sanitize.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Errors

> RFC 9457 problem+json. Branch on code. type URIs live on this site.

Every failure is `application/problem+json`:

```json theme={null}
{
  "type": "https://docs.cortex.foundation/problems/not_found",
  "title": "Not found",
  "status": 404,
  "code": "not_found",
  "detail": "No conversation with id cnv_x.",
  "request_id": "req_…"
}
```

* **`code`** is the contract. Mirror: `@cortex/api-types` `ErrorCode`.
* **`title` / `detail`** are English, for logs and humans reading raw JSON.
  The web app renders catalog copy. Three codes may show `detail` as a
  secondary line: `validation_failed`, `bad_request`, `invalid_state`.
* **`type`** is dereferenceable: [Problem catalog](/problems).
* **`request_id`** is always present and safe to show.

User-facing `detail` names a product surface, never a vendor ("The audio
service is temporarily unavailable.", not a subprocessor's name).

Full catalog: [Problems](/problems).