Scheduled Delivery

Amazon SQS supports delaying the delivery of individual messages through the per-message DelaySeconds parameter, but only up to a hard limit of 15 minutes, and only on standard (non-FIFO) queues.

Wolverine uses this native capability automatically whenever it can. There is nothing to enable — just use Wolverine's normal scheduled sending:

// Delivered through SQS native DelaySeconds (standard queue, within 15 minutes)
await bus.ScheduleAsync(new ValidateOrder(orderId), 5.Minutes());

// Also fine — an absolute time within the next 15 minutes
await bus.ScheduleAsync(new ValidateOrder(orderId), DateTimeOffset.UtcNow.AddMinutes(10));

The decision between native delay and Wolverine's own message scheduling is made per message at the time the message is routed:

Scenario	Behavior
Standard queue, delay ≤ 15 minutes	Sent immediately to SQS with DelaySeconds — the broker holds the message and delivers it after the delay
Standard queue, delay > 15 minutes	Falls back to Wolverine's own message scheduling — the message is sent to SQS when its time arrives
FIFO queue, any delay	Always falls back to Wolverine's scheduled message storage — SQS only supports a queue-level delay on FIFO queues, never per-message delays

A couple of important consequences of the native path:

• Storage-less applications (no message store configured) can now use short, retry-style scheduled sends to standard SQS queues reliably — the broker itself holds the message, so no database is needed and the delay survives an application restart.
• Because the message is handed to SQS immediately, a natively delayed message cannot be cancelled or rescheduled once sent.

For delays past the 15 minute limit (and for all FIFO queues), the fallback behavior depends on your durability setup:

• With a message store configured, the scheduled message is kept in the durable inbox and published to SQS by Wolverine's scheduling agent when the time comes — this is fully durable.
• Without a message store, the message is held by the in-process, in-memory scheduler, and will be lost if the application restarts before the scheduled time.