Is it not possible to either add or update line item properties (aka customAttributes?) post purchase?
Usecase specific I want to add a serial number to some line items on fulfillment when the data is recieved from the WMS integration.
Can’t see this is possible when browsing the Orders API.
Don’t think it’s possible to edit the line items attributes in any capacity from the API once an order has been created.
Is there a reason why this serial number can’t be added before placing the order?
Perhaps orderEditAddCustomItem could work for your case? Though it’s not pretty.
Thats what I thought.
It’s a serial/VIN/chassis number so it is specific from fulfillment (based off the unique item they pick on the shelf) thus we dont even know it at order creation.
Considered orderEditAddCustomItem but it’s wont be relevant i this case unfortunately - thanks for the suggestion!
Will probably end up handling the data outside Shopify 
I’m looking to update order line-item attributes post-purchase. In my search I came across this thread. Add your name to it, hopefully it will help prioritize the feature request.