Flutter app_links Deep-Link Engineering

Mission

Build one secure, testable deep-link pipeline from operating-system delivery to application navigation. Treat app_links as a platform link-delivery adapter only; keep routing, validation, authentication, authorization, deduplication, business idempotency, and user-facing semantics in explicit application layers. Use this governing model:

external URI
→ OS association / registered scheme
→ app_links delivery
→ Uri parsing and origin validation
→ typed DeepLinkIntent
→ duplicate/idempotency gate
→ application readiness
→ authentication
→ authorization / backend validation
→ one router/navigation authority
→ destination

Never collapse these layers. A valid platform association does not make URI contents trusted, and a logged-in user is not automatically authorized for the linked resource.