Inventory

Inventory keeps physical customer stock and virtual SKUU network availability
aligned. Every quantity is an absolute stock level, never a delta.

Two directions

Flow	Direction	Purpose
Physical inventory update	Your platform to SKUU	Tell SKUU that one variant changed at one physical location
Network inventory write	SKUU to your platform	Set one variant's quantity at the virtual `SKUU_Network` location

Your platform remains the source of truth for physical stock. SKUU is the only
party that writes the virtual network location.

Physical inventory updates

Send one signed event for each changed variant and location pair. The quantity
is the new absolute value. A source timestamp determines which update is newer,
while a stable event identity makes exact retries safe.

SKUU acknowledges duplicate deliveries without applying the change twice.

Network inventory writes

SKUU writes only to the assigned virtual SKUU_Network location. The supplied
quantity replaces the previous value and appears in the next Products snapshot.
An identical same-value write succeeds without creating another side effect.

This flow never changes physical customer stock.

Testing the flow

In TESTING, both teams prove one physical update, one exact replay and one
reversible network write. The final readback must show the expected virtual
quantity while every physical quantity remains unchanged.

Technical reference

Deliver a signed Connect event
defines the exact inventory.updated event.
Set virtual SKUU_Network inventory
defines the exact network write.