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

# Introduction

> Explore Notocat's API documentation to integrate newsletter functionality, sync contacts, and automate workflows. Learn about authentication, endpoints, and best practices for leveraging Notocat's powerful features in your applications.

## Welcome

Before you can use Notocat's API, you will need to have a Notocat account and a newsletter. You can [create a Notocat account](https://app.notocat.com/signup) and then [create a newsletter](https://app.notocat.com/add-newsletter). Each newsletter comes with a unique newsletter ID that you can use to interact with your data through the API.

## Authentication

To authenticate with the API, you need to send your API key in the `Authorization` header. The API key must be prefixed with `Bearer `. The header should look like this:

`Authorization: Bearer <token>`

[Click here to get your API key](https://app.notocat.com/user/api)

### Example request

```sh theme={null}
curl "https://api.notocat.com/v1/contacts?newsletter_id=<newsletter_id>" \
  -X GET \
  -H "Accept: application/json" \
  -H "Authorization: Bearer <token>"
```

## How to find the Newsletter ID

You can get the newsletter ID from the URL of your newsletter page in Notocat. Open your newsletter from your dashboard and check the URL in your browser. The newsletter ID starts with `wks_` and has 25 characters like in the picture below:

<img src="https://mintcdn.com/notocat/pbleOL1ROdR9kJQh/images/notocat-newsletter-id.jpg?fit=max&auto=format&n=pbleOL1ROdR9kJQh&q=85&s=8d02e871d504d4eb1fcc2dcc9b4dd3ec" height="250" alt="Noto settings" data-path="images/notocat-newsletter-id.jpg" />