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

# Fix llms.txt returning 404 while llms-full.txt works

> Diagnose why your documentation site's llms.txt file returns a 404 error while llms-full.txt still loads, usually caused by the Don't index project setting.

Mintlify automatically hosts an [`llms.txt`](/docs/ai/llmstxt) file at the root of every documentation site. If `https://yourdocs.com/llms.txt` returns `404` while `https://yourdocs.com/llms-full.txt` loads normally, the most likely cause is the **Don't index project** setting.

## Check the Don't index project setting

When you enable **Don't index project** on the [Add-ons](https://app.mintlify.com/settings/deployment/addons) page of your dashboard, Mintlify returns `404` for `llms.txt` and `/.well-known/llms.txt`. The setting does not gate `llms-full.txt`, which stays available. This mismatch makes the missing `llms.txt` look like a deployment bug when it is a configured behavior.

The Markdown export of each page (the `.md` URL) also keeps its pointer to `/llms.txt` after you enable **Don't index project**, even though that URL returns `404`.

To restore `llms.txt`:

1. Open the [Add-ons](https://app.mintlify.com/settings/deployment/addons) page of your dashboard.
2. Turn off **Don't index project**.
3. Wait for the redeployment to complete. Enabling or disabling indexing redeploys your site, and the change takes effect after the redeployment finishes.

See [Disable indexing for the entire project](/docs/optimize/seo#disable-indexing-for-the-entire-project) for everything else this setting controls.

## Other causes

If **Don't index project** is off and `llms.txt` still returns `404`:

* **Authentication**: On fully authenticated sites, both `llms.txt` and `llms-full.txt` require authentication. Unauthenticated requests fail for both files, not just `llms.txt`. See [llms.txt](/docs/ai/llmstxt) for how authentication affects each file.
* **Reverse proxy routing**: If you serve your documentation through a reverse proxy with a path allowlist, confirm the proxy forwards `/llms.txt` and `/.well-known/llms.txt`. See [Reverse proxy](/docs/deploy/reverse-proxy#routing-configuration).


## Related topics

- [llms.txt](/docs/ai/llmstxt.md)
- [SEO](/docs/optimize/seo.md)
- [Mintlify CLI command reference](/docs/cli/commands.md)