FYI…
A lot of the internal Arc database can be viewed by following the link traversal here.
Help->Troubleshooting->Reveal Arc Data.
Buried in there is a set of JSON objects… one of which is StorableSidebar.json.
This appears to fully capture the folder/tab hierarchy of the sidebar.
This is outside the area of my expertise, but I imagine the Raycast extension uses this to identify the tabs and just invokes Arc with the selected URL.
2 Likes