## 4.1.1 OAuth

The OAuth 2.0 authorization framework enables a third-party application to
obtain limited access to an HTTP service, either on behalf of a resource owner
by orchestrating an approval interaction between the resource owner and the HTTP
service, or by allowing the third-party application to obtain access on its
behalf.

Because your app accesses protected (non-public) data, you need an OAuth 2.0
client ID. This lets your app request authorization to access your
organization's location data on behalf of your app's users. Google APIs use the
OAuth 2.0 protocol for authentication and authorization. Google supports common
OAuth 2.0 scenarios such as those for web server, installed, and client-side
applications.

Learn More

We recommend bundling your ads OAuth requirements when you perform the OAuth
process for connecting your Merchant Center. Learn more about the following:

- [Setting up your Google Cloud Project for your integration](https://developers.google.com/merchant/storebuilder/online/prerequisites#oauth_and_google_cloud_platform_gcp_project_creation)
- [Review our detailed OAuth section to combine Merchant Center and Ads OAuth requirements](https://developers.google.com/merchant/storebuilder/online/sections/1_1_oauth_account_linking)
- [OAuth for the Ads API](https://developers.google.com/google-ads/api/docs/oauth/internals)

> [!IMPORTANT]
> **Important:** Ensure you have set the access_type to offline: access tokens periodically expire and become invalid credentials for a related API request. If you requested offline access to the scopes associated with the token, you can refresh an access token without prompting the user for permission (including when the user is not present).

> [!TIP]
> **Tip:** We highly recommend that you use the OAuth implementation from one of our [Client Libraries](https://developers.google.com/google-ads/api/docs/client-libs).

> [!NOTE]
> **Note:** Request your merchant to grant you read and write access to its Google Account the following OAuth scope: `https://www.googleapis.com/auth/adwords`.