@startuml
!pragma teoz true
skinparam backgroundColor white
skinparam shadowing false
skinparam defaultFontName SansSerif
hide footbox
participant "Caller" as Caller
participant "Stage-in" as Stage
participant "STAC provider" as Provider
participant "Local product directory" as Local
participant "Application" as App
Caller -> Stage: STAC Item URI record
Stage -> Provider: Read Item and download assets
Provider --> Stage: Item metadata and files
Stage -> Local: Save catalog.json, Item JSON and assets\nwith local hrefs
Stage --> App: CWL Directory
App -> Local: Read catalog and resolve asset hrefs
@enduml