> For the complete documentation index, see [llms.txt](https://circleci.com/docs/llms.txt)

# User authentication

CircleCI server currently supports OAuth through GitHub or GitHub Enterprise.

The default method for user account authentication in CircleCI server is through GitHub.com/GitHub Enterprise OAuth.

After your installation is up and running, provide users with a link to access the CircleCI application - for example, `<your-circleci-hostname>.com` – and they will be prompted to set up an account by running through the GitHub/GitHub Enterprise OAuth flow before being redirected to the CircleCI login screen.