== What is a AAT and How to Obtain it ?

An *Authorization API Token* or *AAT* is a special OAuth2 Access Token with the scope *uma_authorization*.

Client applications can obtain an AAT from {{book.project.name}} just like any other OAuth2 Access Token. Usually, client applications obtain AATs after the user is successfully
authenticated in {{book.project.name}}. By default the _authorizaton_code_ grant type is used to authenticate users and issue an OAuth2 Access Token to the client application acting on their behalf.

For demonstrations purposes, the example below uses Resource Owner Password Credentials Grant Type to ask for a AAT.

```bash
curl -X POST \
    -H "Authorization: Basic aGVsbG8td29ybGQtYXV0aHotc2VydmljZTpwYXNzd29yZA==" \
    -H "Content-Type: application/x-www-form-urlencoded" \
    -d 'username=${username}&password=${user_password}&grant_type=password' \
    "http://localhost:8080/auth/realms/${realm_name}/protocol/openid-connect/token"
```

As a result, you will get the following response from the server:

```json
{
  "access_token": ${AAT},
  "expires_in": 300,
  "refresh_expires_in": 1800,
  "refresh_token": ${refresh_token},
  "token_type": "bearer",
  "id_token": ${id_token},
  "not-before-policy": 0,
  "session_state": "3cad2afc-855b-47b7-8e4d-a21c66e312fb"
}
```

== About the uma_authorization scope

The *uma_authorization* scope can be created just like any other _realm role_. Or even as a _client role_. Once you created it, just grant this role to
the users of your realm.