> ## Documentation Index
> Fetch the complete documentation index at: https://developers.autocaption.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Guide to start using AutoCaption API

<Tip>
  API available starting from the [Expert
  Plan](https://app.autocaption.io/pricing)
</Tip>

## How to get your API Key

On the Application: [AutoCaption](https://app.autocaption.io), top right Profile > Usage & API

<Frame style={{width: '50%', display: 'flex', alignItems: 'center', justifyContent: 'center'}}>
  <img src="https://mintcdn.com/autocaption-28/1AxvIrPCOOewlivF/images/api_key.png?fit=max&auto=format&n=1AxvIrPCOOewlivF&q=85&s=360c9333f22512e724dd39a2f66efddf" style={{ width: '100%', borderRadius: '0.5rem' }} width="862" height="544" data-path="images/api_key.png" />
</Frame>

## Authentication

All API endpoints are protected. You must use header authentication

```json theme={null}
x-api-key: your_secret_key
```