inventoryActivate now preserves available quantity

As of API version 2026-04, using the inventoryActivate mutation without specifying an available or onHand argument will no longer default these values to zero. If an item was previously active at a location, any existing active and onHand quantities for the inactive InventoryLevel will be retained.

Why We Made This Change

Previously, inventoryActivate would reset existing inventory quantities to zero, preventing merchants from independently tracking inventory from activation status. This behavior erased quantity history upon activation. The update allows merchants to manage inventory and activation separately, preserving their quantity history.

Impact on Your App

• GraphQL: In the unstable or 2026-04 and later releases, using the inventoryActivate mutation without an available or onHand argument will preserve the pre-activation quantities.
• REST: In the unstable or 2026-04 and later releases, POST requests to inventory_levels/connect.json will retain the pre-activation quantities.

What You Need to Do

• Review any business logic that assumes inventoryActivate resets inventory quantities to zero for specified inventory items and locations.