We'd like to use First Party Sets when enabled, and we'd like to have a way to find out if they're enabled or not in a particular user agent.

We'd like the ability to check on the client side at runtime:

• Does this browser support First Party Sets and is support enabled for this client? (whether it be via something like enterprise management or via a user setting)
• What First Party Set is associated with the current site? (specifically, what are the associated set peer sites)

Mike Fleming
YouTube/Google