---
title: "Configure llms.txt support"
slug: "configure-llms-txt-support"
abstract: "Serve llms.txt content managed in SitecoreAI from a Content SDK Angular SSR server using Express middleware."
---
# Configure llms.txt support

Content SDK Angular apps can serve an `llms.txt` file whose content is managed in SitecoreAI. The file provides large language models and AI agents with a curated overview of the site's content, following the [llms.txt proposal](https://llmstxt.org).

The SDK exposes the configured content at `/llms.txt` with the `text/markdown; charset=utf-8` content type.

> [!note]
> This feature only serves the content configured in SitecoreAI for the resolved site. It doesn't generate `llms.txt` content or aggregate content automatically.

## Register the Express middleware

Use `createLlmsTxtMiddleware` from `@sitecore-content-sdk/angular` in your Angular SSR server. It requires the following:

- Compatible Content SDK packages that include `createLlmsTxtMiddleware`.
- A Sitecore client instance.
- A list of sites (`SiteInfo[]`), commonly imported from `.sitecore/sites.json`.
- `llms.txt` content configured for the site in SitecoreAI.

The Angular app template registers this middleware in `src/server.ts`, after the `robots.txt` middleware. Apps generated from a template that includes this registration require no additional server setup.

To add the endpoint to an existing app, update the SDK packages and add the following imports and registration to `src/server.ts`:

```ts
import { createLlmsTxtMiddleware } from '@sitecore-content-sdk/angular';
import { getClient } from './content-sdk/client/sitecore-client';
import sites from '.sitecore/sites.json';

// Register on the existing Express app before editing, static, and SSR handlers.
app.use(
  '/llms.txt',
  createLlmsTxtMiddleware({
    client: getClient(),
    sites,
  })
);
```

Register the middleware before the editing endpoints, `express.static(...)`, and the Angular SSR handler. Otherwise, another handler can serve a static file or an Angular page instead of the configured content. Use this server-side API in `server.ts`, not in a browser component.

For other server endpoints, see [Angular middleware](https://doc.sitecore.com/sai/en/developers/content-sdk/angular/1x/angular-middleware.html).

### Site resolution

For each request, the middleware resolves the site from the hostname using the supplied site list. It selects the hostname in the following order:

1. The `x-forwarded-host` header, when present.
2. The `host` header, with the port removed.
3. `localhost`, if neither header provides a hostname.

The selected hostname must match a site entry in the supplied list. The middleware doesn't fall back to the app's default site when no hostname matches.

For multisite apps, configure each site's hostnames in the site list so requests to different hosts resolve to the intended sites. Behind a proxy or CDN, ensure that your trusted proxy sets `x-forwarded-host` to the intended hostname. The middleware uses that header as supplied, without removing a port or splitting a list of hosts.

After resolving the site, the middleware calls `SitecoreClient.getLlmsTxt({ siteName: site.name })` to fetch its configured content.

### Responses and caching

| Situation                                       | HTTP status | Response body                                                                    |
| ----------------------------------------------- | ----------- | -------------------------------------------------------------------------------- |
| Content is configured for the resolved site.    | `200`       | The site's configured `llms.txt` content.                                        |
| No content is configured for the resolved site. | `404`       | `# llms.txt\n\n> No llms.txt content configured for this site.` |
| Fetching content throws an error.               | `500`       | `Internal Server Error. If the issue persists, please contact Sitecore Support.` |

The `500` response applies to errors caught while fetching content. An unmatched hostname fails during site resolution and isn't handled by this fetch-error response.

The middleware doesn't configure response caching or provide a `revalidate` option. Each request calls the Sitecore client to fetch content.

## Verify the endpoint

After configuring content in SitecoreAI and starting your SSR server, request `/llms.txt` using a hostname that matches your site list. For example, if `localhost` matches the intended site and the server listens on port `4200`:

```shell
curl -i http://localhost:4200/llms.txt
```

Confirm that the response has status `200`, the `Content-Type: text/markdown; charset=utf-8` header, and the expected content. In multisite apps, repeat the check for each site's hostname.

## SitecoreClient API

Call `SitecoreClient.getLlmsTxt` directly if you need the content outside the provided middleware, for example in a custom server endpoint:

```ts
const content = await getClient().getLlmsTxt({ siteName: 'my-site' });
```

The method returns the configured content as a string, or `null` when no content is configured. The underlying service queries the site's `llmsTxt` value through Experience Edge GraphQL.

## Troubleshooting

| Symptom                                    | Action                                                                                                                |
| ------------------------------------------ | --------------------------------------------------------------------------------------------------------------------- |
| `404` with the placeholder text            | Configure content for the resolved site in SitecoreAI. Check that the request hostname resolves to the intended site. |
| An Angular page or static file is returned | Move the middleware registration before `express.static(...)` and the SSR handler.                                    |
| The request hostname doesn't match a site  | Check the hostnames in `.sitecore/sites.json` and the `x-forwarded-host` value supplied by your proxy or CDN.         |
| `500` with the support message             | Check the server logs and the Sitecore client's connection to Experience Edge.                                        |

To log request timing and fetch errors, enable the `content-sdk:llmsTxt` debug namespace. Site-resolution failures occur before this handler's request logging. See [Debug logging in Content SDK apps](https://doc.sitecore.com/sai/en/developers/content-sdk/angular/1x/debug-logging-in-content-sdk-apps.html).