v139 · capabilities (fugu)

Web Install API

Allows a website to install a web app. The API provides 3 signatures, with 0, 1, and 2 parameters, respectively. When invoked, the website installs either itself, or another site from a different origin, as a web app (depending on the provided parameters). All 3 signatures will be experimented with in parallel.

concepts

  1. Install Call

    Programmatic install for web apps. Replaces the bespoke beforeinstallprompt event handler with an explicit await. Cross-origin install is gated on user activation.

  2. Cross-Origin Storefront

    The 2-arg signature of the API: a storefront page installs other people's PWAs via navigator.install(url). Click cards, see the install result or failure reason in the log.

  3. The Three Signatures

    The 0, 1, and 2 argument call shapes side by side, each with its snippet, runnable button, and the actual API result printed back. Type your own URLs into the cross-origin and id variants.

  4. Install Button Component

    A production-ready install button with all 5 states: not-installable → ready → installing → installed → launch. Simulated state machine with a live PWA install criteria checklist (HTTPS, service worker, manifest, start_url). Feature-detects 'install' in navigator with a ✓/✗ badge.

why it shipped

The web is currently unable to install web apps. The capability must be baked into the platform to allow for websites to distribute content without relying on proprietary protocols or invoking platform specific stores.

references