I see this: https://cloud.google.com/pubsub/subscriber https://cloud.google.com/pubsub/subscriber In the "Delivery contract" section: "For the most part Pub/S

I see this: https://cloud.google.com/pubsub/subscriber https://cloud.google.com/pubsub/subscriber In the "Delivery contract" section: "For the most part Pub/Sub delivers each message once, and in the order in which it was published. However, once-only and in-order delivery are not guaranteed: it may happen that a message is delivered more than once, and out of order." So it is at-least-once delivery as far as I see.