messagequeue

type Message struct {
	// ID uniquely identifies the message for deduplication and tracing.
	ID string

	// Payload is the message body as raw bytes.
	Payload []byte

	// Metadata contains key-value pairs for headers and attributes.
	// Use for trace IDs, request IDs, and cross-service metadata.
	Metadata map[string]string

	// PartitionKey determines which partition/shard this message goes to.
	// Messages with the same PartitionKey are guaranteed ordered delivery.
	// Optional - if empty, backend may use round-robin distribution.
	PartitionKey string

	// PublishedAt is when the message was published (Unix milliseconds).
	PublishedAt int64
}