Add a "launch_handler" web app manifest member that enables web apps to customize their launch behavior across all types of app launch triggers. Example usage: { "name": "Example app", "start_url": "/index.html", "launch_handler": { "client_mode": "navigate-existing" } } This will cause all launches of the Example app to focus an existing app window and navigate it (if it exists) instead of always launching a new app window.
Web apps currently cannot control whether they're launched in a new app window or whether an existing window is reused. This feature helps support web apps that wish to remain in a single window on desktop platforms.
Explainers: https://github.com/WICG/web-app-launch/blob/main/launch_handler.md