WPT details: The API's shape and activation restrictions are tested - https://wpt.fyi/results/web-install. However, web app installs are currently not supported by automated tests, as they require user interaction to confirm the installation. Manual web app testing instructions can be published.
Starting in Chrome 158, the new Web Install API allows websites to prompt users to install a web app, given a manifest URL and optional manifest ID. The `navigator.install()` method enables cross-origin web app installation and provides a better developer experience than handling `beforeinstallprompt` events. This API is launching in parallel with the [HTML <install> element](https://chromeenterprise.google/resources/release-notes/?ver=158&featId=5152834368700416), a declarative entry point to the same installation capability. Admins can control this in either of two ways: 1. With the enterprise policy, [WebAppInstallByUserEnabled](https://chromeenterprise.google/policies/#WebAppInstallByUserEnabled), to disable user web app installs in general, including installs initiated via `navigator.install()` and `<install>`. 2. With permissions policy, [web-app-installation](https://www.w3.org/TR/permissions-policy/), to allow or disallow use of this feature on origins that the enterprise controls (for example, internal sites or iframes).
The web currently lacks the ability for a site to offer installation of a web app identified by a cross-origin manifest. Limited support exists for eligible same-origin web apps via ambient installation affordances and the beforeinstallprompt event. However, the existent browser-provided entry points are difficult for developers to use and users to discover. This capability lets developers distribute web apps across the web without proprietary protocols or platform-specific stores. It brings web app distribution closer to the reach developers expect from other application models while preserving browser-controlled safeguards and explicit user choice.
Docs: https://docs.google.com/document/d/12nSXJLm8mW0gWZ_yjlXfrV8r9gwJliVt4WVa-209-KA/edit?tab=t.0
Samples: https://microsoftedge.github.io/Demos/pwa-install-api https://kbhlee2121.github.io/pwa/web-install-manifest-url/index.html
Explainers: https://aka.ms/webinstall