Drop-in Flutter Dart package for customer license validation & paywalls
Add checkout verification, paywall modal UI, and license key gating to any Flutter iOS, Android, or Web project in 5 minutes.
Every module is structured for maintainability, type safety, and zero bloat.
Pre-styled paywall screen and bottom sheet modal matching Flutter Material 3 & Cupertino.
Verify one-time purchase keys or subscription IDs via API.
Store verified token status using `flutter_secure_storage`.
Clean, modular file organization designed to integrate into your existing project in minutes.
billing_flutter/
├── lib/paywall_guard.dart # Main subscription guard singleton
├── lib/src/paywall_dialog.dart # Native paywall bottom sheet UI
├── lib/src/license_client.dart # License REST API validator
└── example/ # Working sample Flutter appProduction-grade payment processing with cryptographic Svix webhook verification.
Pre-configured signature verification handler for order.created, customer.subscribed, and refund events.
Buyers can manage invoices, upgrade license seats, and access updated repositories anytime.
Instant automated repository invitation via Polar.sh with continuous git pull version updates.
Every starter kit and UI primitive adheres to strict engineering benchmarks.
End-to-End Strict TypeScript & Dart
Verified Webhook Security
Clean, Modular Architecture
Continuous Maintenance
Everything you need to know about licensing, setup, and support.
DevPreFlight provides production-grade starter kits and boilerplates categorized into 3 distinct tiers: Tier 1 (Micro Modules, $19-$29) for single-purpose utilities like webhook handlers or UI kits; Tier 2 (Core Feature Kits, $49-$69) for core auth, payment, and database setups; and Tier 3 (The All-in-One Mega Starter Kit, $99-$149) for complete full-stack SaaS boilerplates with lifetime updates and instant GitHub repository access.