Amazon SNS Notification Message

Schema for Amazon SNS notification messages delivered to HTTP/S endpoints, SQS queues, and email-json subscribers. When a message is published to an SNS topic, SNS wraps it in a JSON notification envelope containing the message, topic ARN, timestamp, cryptographic signature for verification, and an unsubscribe URL. This schema covers all three message types: Notification, SubscriptionConfirmation, and UnsubscribeConfirmation.