CLI Reference


Manage and configure your Fern projects, all from the command line.

Use the Fern CLI to manage and test your documentation, SDKs, permissions, and API specification from the terminal or via an automated system.

Check out the API Reference to interact with Fern programmatically.

Installing Fern CLI

Run the following command to download and install Fern CLI from the npm registry.

$npm install -g fern-api

Updating Fern CLI

When there is a newer version of Fern CLI available, running any command will trigger an alert. To update Fern, run the same installation command yet again.

$npm install -g fern-api@latest

Run fern upgrade to update the Fern CLI and your project’s generators.

Checking the version

Use --version, shorthand -v, to check the Fern CLI version currently being used.

$$ fern -v

Authentication and CI/CD

Fern CLI requires authentication before accessing an organization’s resources. To authenticate manually, login using GitHub using fern login. To enable Fern CLI use in CI/CD environments, and for an example showing how to set up Fern and GitHub Actions, check out fern token.