There should be a way to inform the Kafka attribute "key" in the responses based in Safer Payments attributes other than URID that is what is used with no other option.

Currently, IBM Safer Payments generates Kafka response events informing the message "key" with the Safer Payments URID with no chance to change this behavior.

There should be a way to change it and use an optional attribute selected in the GUI for example.

Why is it useful to assign a specific key to a Kafka message?

1. Ensures message ordering per key
   • Kafka guarantees the order of messages within a partition. When you assign a key, Kafka uses it to determine the target partition.
   • This means that all messages with the same key go to the same partition, and therefore, they are processed in order. This is crucial for maintaining consistency in event streams related to the same entity (e.g., a user, order, or session).
2. Enables logical load distribution
   • Keys help distribute messages more predictably and evenly across partitions.
   • This allows consumers to scale horizontally while preserving logical grouping by key.
3. Facilitates debugging and replay
   • If you need to reprocess events for a specific key (e.g., a customer ID), you can easily locate the partition and replay the relevant messages efficiently.
4. Improves performance and storage locality
   • Keeping related data together in the same partition improves data locality, which can reduce latency and enhance read performance.
5. Essential for patterns like Event Sourcing or CQRS
   • These architectural patterns rely on event streams to reconstruct state. Maintaining the correct order of events per entity (via the key) is critical for accurate state reconstruction.