# Introduction

> Welcome to the Fern API Reference.

<Warning title="Pro and Enterprise feature">
  This feature is available only for the [Pro and Enterprise plans](https://buildwithfern.com/pricing). To get started, reach out to [support@buildwithfern.com](mailto:support@buildwithfern.com).
</Warning>

The Fern AI API allows you to manage your Ask Fern configuration using Fern's public RESTful API. You can use the API to:

* Build your own support integrations that leverage Ask Fern's AI-powered search
* Add custom context and FAQs to your documentation
* Source usage and analytics data from your Ask Fern instances

## Authentication

Fern API requests require a bearer token for authentication. Use the CLI command [`fern token`](/learn/cli-api/cli-reference/commands#fern-token) to generate a bearer token. Tokens don't expire.