> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cortex.foundation/llms.txt
> Use this file to discover all available pages before exploring further.

# upstream_timeout

> An upstream service timed out. HTTP 504.

|           |                                                            |
| --------- | ---------------------------------------------------------- |
| HTTP      | `504`                                                      |
| `code`    | `upstream_timeout`                                         |
| `type`    | `https://docs.cortex.foundation/problems/upstream_timeout` |
| Retryable | yes                                                        |

A dependency did not answer within its budget. Same product-language rule as `upstream_failure`.

```json theme={null}
{
  "type": "https://docs.cortex.foundation/problems/upstream_timeout",
  "title": "An upstream service timed out",
  "status": 504,
  "code": "upstream_timeout",
  "request_id": "req_…"
}
```

## Related

* [Errors](/reference/errors) - how to branch on `code`, and what not to render from `detail`.
* [Problem catalog](/problems) - every code, its status, and whether retrying helps.
* [Troubleshooting](/getting-started/troubleshooting) - what a message in the product means.