Interface SnsLambdaConsumerArgs

SNS topic for the DLQ's message-age alarm. Required, not optional, for the same reason as LambdaApp.alarmTopicArn: a dead-letter queue that silently ships without this alarm is precisely the failure the alarm exists to catch — the queue looks healthy and the event is deleted at retention.

Passed in rather than read from ALARM_TOPIC_ARN inside this file, which is the standing convention for everything in this package. A shared component that resolves a stack output itself makes the coupling invisible at every call site: when alarmTopicArn moved to cfx-ecs (now cfx-vpc) on 2026-08-03, ~20 lambda stacks broke at once in a file none of them mention. Every caller here already imports ALARM_TOPIC_ARN.

More topics the same function consumes, each with its own permission and subscription, all parking in the one DLQ. A second consumer on the function would instead fight over its single on-failure destination and dlq-send policy. key names the resources; never rename it.

SNS message-filter policy, already serialized. Omit to receive everything.

Filtering is a real decision, not a default: SNS ANDs its filter keys, so a predicate that is an OR across two attributes cannot be expressed here at all and has to move into the consumer (see the reward consumer). An event allow-list must be the list the handler's dispatch is typed on, as every internal-bus consumer's is (InternalEventHandlers), or it drifts.

The consuming function. aws.lambda.Permission identifies it by NAME, aws.sns.TopicSubscription needs its ARN, and role (the execution role ARN) is the principal that sends a failed invocation to the DLQ.

DLQ retention. Defaults to 14 days.

Topic to subscribe to, e.g. CUSTOMER_EVENTS_TOPIC_ARN.