> For the complete documentation index, see [llms.txt](https://docs.overflowcms.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.overflowcms.com/api-reference/errors.md).

# Errors

## Errors

### Errors

#### Errors

Every error response, regardless of status code, is shaped the same way:

```json
{
  "error": {
    "code": "not_found",
    "message": "Collection not found"
  }
}
```

| HTTP status | `code`             | When                                                                                                                                                                                             |
| ----------- | ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| 404         | `invalid_token`    | The public token in the URL doesn't resolve to any site.                                                                                                                                         |
| 404         | `not_found`        | The collection slug doesn't exist on this site, or the requested item doesn't exist / isn't published.                                                                                           |
| 403         | `plan_required`    | The site's plan doesn't include a feature the endpoint requires — AI search/related items below Pro, or a `filter[...]`/`search` param on the list endpoint below Pro (see Collections & Items). |
| 400         | `bad_request`      | A required parameter is missing or invalid (e.g. `/search` called without `q`).                                                                                                                  |
| 502         | `embedding_failed` | The embedding model failed to embed the search query.                                                                                                                                            |

`code` is the stable, machine-checkable value — branch on it rather than on `message`, which is meant for humans and may be reworded.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.overflowcms.com/api-reference/errors.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.