# Page Not Found

The URL `published-documentation/custom-domains/how-can-i-add-a-custom-domain-to-a-docs-site` does not exist. This page may have been moved, renamed, or deleted.

## Suggested Pages

You may be looking for one of the following:
- [How can I change the slug in the URL?](https://gitbook.com/docs/help-center/published-documentation/custom-domains/how-can-i-change-the-slug-in-the-url.md)
- [Change or update my custom domain in GitBook](https://gitbook.com/docs/help-center/published-documentation/custom-domains/change-or-update-my-custom-domain-in-gitbook.md)
- [My custom subdomain isn't working](https://gitbook.com/docs/help-center/published-documentation/custom-domains/my-custom-subdomain-isnt-working.md)
- [How can I solve the "path is already taken" error?](https://gitbook.com/docs/help-center/published-documentation/custom-domains/how-can-i-solve-the-path-is-already-taken-error.md)
- [How do I change or replace the favicon for my docs site?](https://gitbook.com/docs/help-center/published-documentation/customization/how-do-i-change-or-replace-the-favicon-for-my-docs-site.md)

## How to find the correct page

If the exact page cannot be found, you can still retrieve the information using the documentation query interface.

### Option 1 — Ask a question (recommended)

Perform an HTTP GET request on the documentation index with the `ask` parameter:

```
GET https://gitbook.com/docs/help-center/published-documentation/custom-domains/how-can-i-change-the-slug-in-the-url.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.

### Option 2 — Browse the documentation index

Full index: https://gitbook.com/docs/sitemap.md

Use this to discover valid page paths or navigate the documentation structure.

### Option 3 — Retrieve the full documentation corpus

Full export: https://gitbook.com/docs/llms-full.txt

Use this to access all content at once and perform your own parsing or retrieval. It will be more expensive.

## Tips for requesting documentation

Prefer `.md` URLs for structured content, append `.md` to URLs (e.g., `/docs/help-center/published-documentation/custom-domains/how-can-i-change-the-slug-in-the-url.md`).

You may also use `Accept: text/markdown` header for content negotiation.