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  • CLI Reference
    • Get Started with Fern CLI
    • Global Options
    • Commands
    • Changelog
  • API Reference
    • Overview
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On this page
  • Installing Fern CLI
  • CLI Quick Start
  • Common Workflows
CLI Reference

Overview

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

Explore Fern CLI global options.
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Installing Fern CLI

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

$npm install -g fern-api # install Fern CLI
$fern -v # ensure Fern was successfully installed

CLI Quick Start

Get started with these commonly used commands:

Common Commands
$# Docs Development
$fern init --docs                  # Create a new documentation project
$fern docs dev                     # Preview docs locally at localhost:3000
$fern generate --docs --preview    # Preview documentation changes
$fern generate --docs              # Generate and publish documentation
$
$# SDK Development
$fern init                        # Start new SDK project
$fern check                       # Validate API definition
$fern generate --preview          # Preview SDKs in .preview/ folder
$fern generate                    # Generate default SDK group
$fern generate --group ts-sdk     # Generate specific SDK group

The “default SDK group” refers to the group marked as default in your generators.yml. Learn more about default groups.

Common Workflows

Setting up Docs
  1. Initialize a new docs project:
$fern init --docs
  1. Preview locally while making changes:
$fern docs dev
  1. When ready to preview or publish:
$fern generate --docs --preview  # Generate a shareable preview link
$fern generate --docs            # Publish to production
Setting up SDK generation
  1. Initialize a new SDK project:
$fern init

  1. Configure your generators in configuration options

  2. Generate SDKs:

$fern generate --preview                     # Preview changes locally
$fern generate --group python-sdk --preview  # Preview specific SDK group
$fern generate                               # Publish to production

During development, use --preview to test your changes locally before publishing. The preview SDK will be generated into the .preview/ folder.