Well-known files & llms.txt

Well-known files enable features like Apple app site association, Apple Pay, Android link verification, llms.txt. You can also use them to publish a security.txt file, which provides contact details for reporting website security vulnerabilities.

This feature is available on Pro, Business and Enterprise plans. You can host up to 30 well-known files per project, stored in the /.well-known/ path, or for llms.txt on the root (/). Both TXT and JSON formats are supported. Subfolders within this path are not allowed.

File naming conventions

While uploading, make sure the files meet naming conventions required by third-party services. For example:

• Apple app site association: The file must be named apple-app-site-association (no file extension) so it’s accessible at example.com/.well-known/apple-app-site-association.

• Android asset links: The file must be named assetlinks.json so it’s accessible at example.com/.well-known/assetlinks.json.

• llms.txt: The file must be named llms.txt so it’s accessible at example.com/llms.txt.

Incorrect naming—such as omitting the .json extension—can cause functionality issues.

If a file is uploaded with trailing spaces or special characters (e.g., security .txt), these are automatically removed. The corrected name, such as security.txt, will be used.

How to upload well-known files

To upload well-known files:

1. Open your project settings.

2. Locate the “Well-Known Files” section.

3. Upload your TXT or JSON files.

4. Publish your site

   1. If your site has Staging enabled, deploy the latest version

Once your site is published, the files will be available at the /.well-known/* / /llms.txt path.

Common Examples

You can find more examples on Wikipedia or well-known.dev.