Hi Anders

For inventory bulk update I wouldn't go with Service API, instead you can use IWarehouseInventoryService.Save(IEnumerable<IWarehouseInventory> inventories)  method that accepts a list of inventories. Alternatively, you can use IInventoryService.Save(IEnumerable<InventoryRecord> records) as well

Just as Vincent said, you can easily add a new endpoint to update inventories of multiple SKUs at once (however, arguably that's no longer RESTful). The SKU (entry) is the resource and inventories and prices are parts of that resource. It's be tricky if you design that endpoint, but if you ignore some RESTful rules then it's doable. I do think that a scheduled job is a better fit for such job - both for inventories and prices. Just one note: IWarehouseInventoryService and IWarehouseInventory are obsolete and removed in later version, you should stick with IInventoryService/InventoryRecord

Thank you for your help. I guess that is the way to go.

I guess I was just hoping that the Service API could do more than it actually can.

@Quan Mai: Well, I don't know if the Catalog Import is very RESTful. But it can be very useful :)
Can I use the Catalog Import to update inventory, by only specifying Code of the Entry and the updated WarehouseInventory element(s)?

It may not be intuitive, but if it works and performs well, this may be what we need.

We probably need to invest in understanding the Catalog.xml format anyway to update our product catalog from our PIM system. So if we can also use it to update inventory based on updates from ERP, this may be ok. But we will need separate integration flows (with separate data), since catalog and inventory updates will come from separate systems.

We don't expect to store prices in Optimizely commerce, since our price logic is completely custom for our B2B scenario. We have customer-specific prices on most of the items, and it must match the business logic from the ERP system.