When a batch has completed processing, you'll get the event payload as below:
{
event_type: "batch.finished",
resource_type: "shipment_batch",
resource_id: "3ed3d05f-7ba8-404d-97b1-5a50de300001",
batch: {
started_at: "2023-01-25T11:30:00.000Z",
finished_at: "2023-01-25T11:31:00.000Z",
state: "processed",
items: 2,
failed_items: 0
}
}