Preventing duplicate state writes during GAS server reconciliation

When utilizing the Gameplay Ability System (GAS) in Unreal Engine 5, the server maintains authority over state changes while clients use Prediction Keys to anticipate outcomes. In scenarios where a server-side reconciliation occurs due to a state mismatch, the client must roll back to the last authoritative state.

A challenge arises when integrating custom persistence layers or external databases that trigger writes based on these state changes. If a client-predicted action triggers a write and the subsequent server reconciliation triggers another update for the same event, there is a risk of duplicating entries or creating inconsistent state logs.

What is the recommended architectural approach to ensure idempotency for external writes during a GAS reconciliation event? Which mechanism should be used to correlate a predicted client action with its final server-authoritative resolution to prevent redundant data commits?