To enable the Video Stitcher API for your project, please reach out to your Account Representative or contact Sales to learn more.

Prepare for your client application to work with Google Ad Manager

Collect the required information for your client applications

You should have the following information that is required for Google Ad Manager to create a live stream session:

Field	Description
`projectNumber`	The Google Cloud project number (`PROJECT_NUMBER`) used to create Ad Manager-enabled sessions; alternatively, you can use the project ID.
`region`	The location (`LOCATION`) where the live configuration is registered.
`liveConfigId`	The live configuration ID used to register the livestream event with the Video Stitcher API. The following shows the format for the full config resource name: projects/`PROJECT_NUMBER`/locations/`LOCATION`/liveConfigs/`LIVE_CONFIG_ID` The config ID is the last part of the full name (`LIVE_CONFIG_ID`). Keep in mind that the location of the config must be in the same location in which you create the session.
`customAssetKey`	The custom asset key (`CUSTOM_ASSET_KEY`) created during the live configuration registration; the IMA SDK needs this value to create the stream.
`networkCode`	The numeric identifier (`NETWORK_CODE`) for your Ad Manager network.
`oAuthToken`	A short-lived OAuth token for the service account with the Video Stitcher User role. See Generate short-lived OAuth tokens.

Table 1. Required information for Ad Manager-enabled live stream sessions

Generate short-lived OAuth tokens for testing

To generate a short-lived OAuth token associated with the service account with the Video Stitcher User role, follow these steps:

Replace PATH_TO_YOUR_SERVICE_KEY with the path to the JSON file you downloaded to your local machine.
```
gcloud auth activate-service-account --key-file PATH_TO_YOUR_SERVICE_KEY
```
Retrieve the OAuth 2.0 bearer token from the service account:
```
gcloud auth print-access-token
```

Because this is a short-lived token, you need to generate it again periodically with the gcloud auth print-access-token command and send the new tokens to your client applications. See the following section for more information on building a production service to provide short-lived tokens.

Create a service to provide information to your client applications

Create a service that can provide the required information to be passed to the client. When the application requests information from your service on how to play a live stream, the service should return the information described in Table 1.

In particular, the service must be able to provide OAuth tokens to client applications in a secure manner. Configure this service using two service accounts, one impersonating the other. One service account has the Service Token Creator role and creates an OAuth token for the service account that has the Video Stitcher User role. For example:

Service account 1: This is the caller service account. This account has the Service Token Creator permission on service account 2 and impersonates service account 2 to client applications.
Service account 2: This is the privilege-bearing service account that has the Video Stitcher User role to create sessions.

For information on providing an OAuth token from your service, including client library code samples, see Create a short-lived access token.

Create a configuration for a livestream event

Android