pubsubTopic property

The name of the Pub/Sub topic where budget-related messages are published, in the form projects/{project_id}/topics/{topic_id}.

Updates are sent to the topic at regular intervals; the timing of the updates is not dependent on the [threshold rules](#thresholdrule) you've set. Note that if you want your Pub/Sub JSON object to contain data for alertThresholdExceeded, you need at least one [alert threshold rule](#thresholdrule). When you set threshold rules, you must also enable at least one of the email notification options, either using the default IAM recipients or Cloud Monitoring email notification channels. To use Pub/Sub topics with budgets, you must do the following: 1. Create the Pub/Sub topic before connecting it to your budget. For guidance, see Manage programmatic budget alert notifications. 2. Grant the API caller the pubsub.topics.setIamPolicy permission on the Pub/Sub topic. If not set, the API call fails with PERMISSION_DENIED. For additional details on Pub/Sub roles and permissions, see Permissions required for this task.

Optional.