Optional installed-app recipes

These recipes add OS-facing PWA capabilities only when a product has a concrete use case. They are not part of the generated starter and unsupported browsers keep the normal web experience.

Available

• Inbound and outbound Web Share — share text or links through the OS sheet and receive an untrusted draft through an optional installed-app share target.
• Launch handling and client reuse — safely focus or navigate an existing installed window while preserving ordinary launch behavior elsewhere.
• File handling and import previews — validate explicitly associated files into transient drafts before the user confirms persistence.
• Custom-protocol item links — parse one product-owned web+ scheme into allow-listed collaborative-list identifiers without arbitrary redirects.
• Related-application discovery — hide redundant companion onboarding from exact verified-app matches without changing authentication or PWA installability.
• Cross-origin app-window scope — keep product-owned secondary-origin paths inside an installed window after reciprocal deployment verification.
• Desktop window controls overlay — use noncritical titlebar space without obscuring system controls, while preserving the standalone layout.

Contract for every recipe

• Keep the capability absent until the application opts in.
• State the product use case and current browser/OS support.
• Feature-detect and preserve a useful ordinary-web fallback.
• Ask for permission only after a user action that explains the value.
• Treat launch payloads, files, URLs, messages, and subscription data as untrusted input.
• Explain whether an install, reinstall, manifest refresh, or worker update is required.
• Test direct browser navigation, installed launch, offline startup, unsupported browsers, malformed input, and removal of the capability.

Foreground recovery remains lofi's portable baseline. A recipe never moves Jazz sync or OPFS into the service worker without a separate architecture decision.