# Custom error pages

All apps have a system-generated error page that you can override. To override, simply add a page with the reserved nav slug of <mark style="color:red;">`/error`</mark> and you can create and customize your own page. Error detail data is saved to the <mark style="color:red;">`app`</mark> model as <mark style="color:red;">`app.error`</mark>, and can be accessed in the error page. The error object looks like this:

```json
{
	"error": {
		"code": "404",
		"description": "Page Not Found",
		"message": "Page not found for slug: nopage"
	}
}
```


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# Agent Instructions: 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:

```
GET https://docs.klai.studio/engineering-reference-docs/betterforms-error-pages-api/custom-error-pages.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

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.