The missing macOS web app wrapper: a tiny native Swift shell that opens a specific URL in a WebKit window with as little visible chrome as macOS will allow. No address bar, no tab strip, no bookmark bar — just the page in a native window. Safari Web Apps bring too much browser furniture; Web App Viewer brings none.
Each window is a WKWebView that fills the frame. An invisible draggable strip at the top (right of the traffic lights) lets you move the window even with the titlebar suppressed. Traffic-light controls hide when the window isn't active. The default URL comes from DefaultWebAppURL in Info.plist — change it and rebuild. A Share Extension, a macOS Service, and a webappviewer://open?url= URI scheme round out the integration surface.
No toolbar, no address bar, no fullscreen frame — just the page.
Set DefaultWebAppURL in Info.plist once; it opens on launch.
"Open in Web App Viewer" appears in the Services menu and the system Share sheet.
webappviewer://open?url=… for external integrations and scripts.
Narrow draggable area lets you move the window without visible titlebar chrome.
One command; app bundle at .build/WebAppViewer.app.