I’m using the admin api to update fulfilment events from our shipper’s api to Shopify.
I noticed, that the two endpoints for this accept different values:
What’s the difference between these, which is the best to use, and how do they relate to each other? I.e. if I set a status as PICKED_UP using the customer API, how does that map to the admin api, which does not allow that status?
Are you able to do it with Customer API at all? I though you can’t.
I haven’t - I said ‘if’ 
.
You’re saying the customer API is read only?
Wondering how those statuses [that only exist in the customer account api, like PICKED_UP] ever get set then - are they based on some Shopify logic where if the fulfillment went from ‘READY_FOR_PICKUP’ → DELIVERED, customer sees ‘PICKED_UP’, for example?
No, Customer API is not read-only, but there is just a handful mutations. It’s rather Customer Account API.
As for the statuses – I have no experience.
Worth setting them with Admin API and checking in Customer API?
Sorry - I think that was just a nomenclature issue - I meant the customer account api