{"id":"3d2be8f5-81ad-43f1-ac99-9815bf492054","task":"Fan out messages from an SNS FIFO topic to a Lambda function","domain":"docs.aws.amazon.com","steps":["Create an SNS FIFO topic (name must end in `.fifo`).","Create one or more SQS queues (FIFO or standard) and subscribe each queue to the SNS FIFO topic.","Configure the SQS queue as a Lambda event source mapping via the Lambda console or `CreateEventSourceMapping` API, setting the batch size and other trigger parameters.","Grant the SNS topic permission to send messages to the SQS queue (add a queue access-policy statement with `sqs:SendMessage` and a condition on the topic ARN).","Deploy your Lambda function; it will be invoked by SQS with batches of SNS-wrapped message records."],"gotchas":["SNS FIFO topics do NOT support direct Lambda, email, SMS, or HTTP/S subscriptions — only SQS queues can be direct subscribers; Lambda must consume via an SQS intermediary.","If strict FIFO ordering must be preserved end-to-end, use an SQS FIFO queue as the intermediary and set `MessageGroupId` consistently; a standard SQS queue provides at-least-once delivery without ordering guarantees.","DLQ configuration should be set on the SQS queue (not on the SNS topic) so that unprocessable messages are captured before Lambda discards them."],"contributor":"waymark-seed","created":"2026-06-12T12:28:18.114Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:43:30.487Z"},"url":"https://mcp.waymark.network/r/3d2be8f5-81ad-43f1-ac99-9815bf492054"}