Fallback Policies

Control where visitors go when app handling is unavailable.

Link mobile behavior#

Every Link has an explicit mobile experience contract:

web_only — always redirect to the web destination. No app-open choice.
app_preferred — show app-open choice with web continuation when a matching target exists.
app_required — never use mobile web. Show install/store actions only.

Note

Link intent cannot be weakened by a Fallback Policy. An app_required Link never falls back to mobile web.

Mobile fallback modes#

web_redirect — redirect to the Link or Fallback Policy web destination.
store_redirect — redirect to the platform store URL from the Domain + App Platform binding.
install_page — render a branded page with explicit Open App and Store actions.

Desktop behavior#

web_redirect — redirect to the configured web URL.
not_found — return 404 for desktop traffic.

Versioned policy rules#

Fallback Policies can match on platform, source, country, SDK App ID, App Platform ID, or named query parameters. Rules support exact equals and not_equals comparisons only.

Warning

Regular expressions, executable expressions, and arbitrary client-supplied redirect destinations are not supported. This prevents open redirects.

Store ownership#

Store URLs belong to the Domain + App Platform binding, not to individual Links. This keeps store identity reusable and consistent. A Link stores behavior, never App Store or Play Store URLs directly.