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

# Step 1: Authenticate

> Authenticate with the GBG GO API by exchanging your client credentials for an access token required for all subsequent API calls.

Before you can use the GBG GO API, you must authenticate your request. This involves exchanging your API client credentials for an access token.

## What you need

Before requesting an access token, make sure you have created an API client and have the following credentials:

* **Client ID**: Identifies your API client.
* **Client secret**: A secure key generated when you create the API client.

<Note>
  You create API clients in the **Clients** tab of the Account management portal. See [Manage API clients](/docs/go-v2/platform/account-management/manage-api-clients) for instructions.
</Note>

## Request an access token

To get your access token, send a `POST` request to the token endpoint using the `client_credentials` grant type.

You can send a request like this:

```bash BASH theme={null}
curl --request POST \
  --url https://api.auth.gbgplc.com/as/token.oauth2 \
  --header 'Content-Type: application/x-www-form-urlencoded' \
  --data 'grant_type=client_credentials' \
  --data 'client_id=your-client-id' \
  --data 'client_secret=your-client-secret' \
  --data 'scope=gbg.token'
```

If your request is successful, the API will return a response in this format:

```json JSON theme={null}
{
  "access_token": "your-access-token",
  "token_type": "Bearer",
  "expires_in": 3600
}
```

Store your access token securely and refresh it when it expires.

Refer to the [Generate access token](/docs/go-v2/api-reference/endpoint/generate-access-token) API reference for details on the request and response definitions.

## FAQ

<Accordion title="What is the authentication URL and how do I get a token?">
  To authenticate, send a `POST` request to the token endpoint:

  ```json JSON theme={null}
  https://api.auth.gbgplc.com/as/token.oauth2
  ```

  The request must be sent with the following parameters:

  | Parameter       | Description                  |
  | --------------- | ---------------------------- |
  | `grant_type`    | Set to `client_credentials`. |
  | `client_id`     | The client ID.               |
  | `client_secret` | The client secret.           |
  | `scope`         | Set to `gbg.token`.          |

  Example request:

  ```bash BASH theme={null}
  curl --request POST \
    --url https://api.auth.gbgplc.com/as/token.oauth2 \
    --header 'Content-Type: application/x-www-form-urlencoded' \
    --data 'grant_type=client_credentials' \
    --data 'client_id=your-client-id' \
    --data 'client_secret=your-client-secret' \
    --data 'scope=gbg.token'
  ```

  A successful response returns:

  ```json theme={null}
  {
    "access_token": "your-access-token",
    "token_type": "Bearer",
    "expires_in": 3600
  }
  ```

  Include the token in the `Authorization` header of subsequent API request as `Bearer your-access-token`. Store the token securely and refresh it before it expires.

  You create API clients yourself in the **Clients** tab of the Account management portal, where you generate the client ID and client secret used to authenticate. For details, see **Manage API clients** in Account management.
</Accordion>

## Next step

Go to [Step 2: Start a journey](/docs/go-v2/developer-integration/execute-customer-journeys/start-a-journey-step) to create a new journey instance.