// the find
square/in-app-payments-flutter-plugin
Flutter Plugin for Square In-App Payments SDK
A Flutter wrapper around Square's native In-App Payments SDKs for Android and iOS. If you're building a Flutter app that takes payments and your merchant is already on Square, this is the official path. If they're not on Square, keep moving.
Official Square-maintained plugin with proper Apple Pay and Google Pay support baked in, not bolted on. The nonce-based payment flow is the right architecture — card data never touches your server. Solid documentation with separate guides for Apple Pay, Google Pay, and getting started. Localization support across seven locales in both iOS and Android layers.
Wrapping native SDKs in Objective-C/Java means Flutter-layer bugs can be nearly impossible to debug without dropping into platform-specific toolchains. The Android side still requires minSdkVersion 28 (Android 9), cutting out a non-trivial slice of lower-end devices in emerging markets. No refund support — you have to call Square's REST API separately, which means a backend is mandatory for any production use. The plugin is Square-only: there's no abstraction layer, so switching processors means rewriting the entire payments integration.