---
title: Authentication
slug: api/authentication
createdAt: 2026-07-17T12:22:29.117Z
---

There are several ways to authenticate with ENGINE4. Depending on the authentication method, different requests are sent to the /token endpoint:

## Password

You can obtain an access token using your user account (username and password) by sending the following request:

:::BlockQuote
\{
  "client\_id": "YOUR\_CLIENT\_ID",
  "grant\_type": "password",
  "username": "YOUR\_USERNAME",
  "password": "YOUR\_PASSWORD",
}
:::

## ClientSecret

You can obtain an access token using your client secret by sending the following request.

:::BlockQuote
\{
  "client\_id": "YOUR\_CLIENT\_ID",
  "grant\_type": "client\_credentials",
  "client\_secret": "YOUR\_CLIENTSECRET"
}
:::

## Usage

Authentication for the remaining API endpoints is performed using the Authorization HTTP header, with the access token being transmitted as a Bearer token.

:::BlockQuote
\{
  "Authorization": "Bearer YOUR\_ACCESS\_TOKEN"
}
:::