On macOS, the desktop app can be your default web browser. Links you open from other apps then open in T3 Code. When the thread on screen shows its browser panel, the link opens there as a new tab. Otherwise it starts a new thread without a project, with the browser panel maximized on the page, so you can ask an agent about it right away.
Choose T3 Code under System Settings → Desktop & Dock → Default web browser. To go back, choose another browser there.
HTML files you open from Finder open the same way.
A link that launches T3 Code waits until the app has connected to its environment, then opens.