MessageId => Str

Unique identifier assigned to the published message.

Length Constraint: Maximum 100 characters

SequenceNumber => Str

This response element applies only to FIFO (first-in-first-out) topics.

The sequence number is a large, non-consecutive number that Amazon SNS assigns to each message. The length of "SequenceNumber" is 128 bits. "SequenceNumber" continues to increase for each "MessageGroupId".

_request_id => Str