Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Replaying retained events to a subscriber

To deliver events that the bus already holds, create a subscriber with --starting-position POINT_IN_TIME and a starting point inside the bus's retention window, for example --point-in-time-configuration '{ "PointType": "TIMESTAMP", "StartingPoint": "2026-09-01T00:00:00Z" }'. There is no separate replay API: a subscriber reads retained events from its starting position, so anything still inside the retention period can be delivered again. DescribeEventBus returns RetentionWindowStartTime, the earliest point a subscriber can read from; on a new bus that is the bus's creation time, so a recent timestamp can still fall outside the window. For the retention period itself, see Choosing the retention period.

Starting position

When you create a subscriber, --starting-position is LATEST to receive only events published after the subscriber exists, or POINT_IN_TIME to read from retained history. With POINT_IN_TIME, --point-in-time-configuration sets PointType to HORIZON, the earliest retained event, or to TIMESTAMP with a StartingPoint. The starting point must fall inside the retention window: at or after RetentionWindowStartTime and not in the future. An optional EndPoint stops the subscriber at that time. Omit EndPoint and the subscriber reads through the retained events, catches up to live events, and keeps delivering.

aws eventsv2 create-subscriber \
    --name reprocess-september \
    --event-bus-arn arn:aws:events:us-east-1:111122223333:event-busv2/orders/EXAMPLE1234567890abcdef \
    --starting-position POINT_IN_TIME \
    --point-in-time-configuration '{ "PointType": "TIMESTAMP", "StartingPoint": "2026-09-01T00:00:00Z" }' \
    --invoke-configuration '{
        "TargetArn": "arn:aws:sqs:us-east-1:111122223333:reprocess",
        "RoleArn": "arn:aws:iam::111122223333:role/EventBusDeliveryRole"
    }'

A replay has a startup delay and then runs at live speed. Allow for the delay before you conclude that a replay is not working. To pause a subscriber and later resume it with or without the backlog, see Pausing and resuming.

Telling replayed events apart

Every delivered event carries SystemMetadata."aws:DeliveryType", which is LIVE for an event delivered as it arrived and REPLAY for an event read from retained history. Use it to make consumers idempotent during a replay.