Connecting Nostr apps to external wallets is accomplished via the Nostr Wallet Connect protocol. It utilizes Nostr’s public relay infrastructure to enable communication between apps and wallets. You can learn more about this protocol here, and access developer docs here.

The smooth, two-click connection setup UX is implemented through deep links between Primal and the external app. Here’s the deep link that the external app needs to call to invoke this feature:

nostrnwc+primal://connect?appicon=[icon_url]&appname=[app_name]&callback=[callback_string]

After the user clicks “Create Wallet Connection” in Primal, the Primal app calls the deep link defined in the callback, and passes the NWC connection string. That’s all that the external app needs to make the wallet connection.