> This page is for Docs.

> For clean Markdown content of this page, append .md to this URL. For the complete documentation index, see https://buildwithfern.com/learn/llms.txt.

## Custom `llms-full.txt` files are deprecated

ai, docs.yml, deprecated

Fern no longer generates `llms-full.txt`, and the `llms-full-txt` configuration in `docs.yml` is deprecated. Concatenating an entire site into one file exceeded most model context windows, added heavy serving overhead, and saw little use next to `llms.txt` combined with per-page Markdown.

Use `llms.txt` to discover page URLs and fetch individual pages via their [`.md` URLs](/learn/docs/ai-features/markdown).

To serve a custom `llms.txt`, see [Serve custom files](/learn/docs/ai-features/customize-llm-output#serve-custom-files).

Read the docs

## API catalog respects site authentication and RBAC

security

The `/.well-known/api-catalog` endpoint now mirrors what the viewer can see. Sites with authentication configured return an empty catalog to unauthenticated requests, and API references hidden through role-based access control no longer appear in the catalog.

Read the docs