Pinput Flutter Skill

Purpose

This skill provides authoritative, production-grade engineering instructions for integrating, styling, validating, securing, and testing PIN codes and OTP inputs in Flutter applications using the pinput package (v6.0.2+).

When to Use This Skill

• Building SMS verification, two-factor authentication (2FA), phone authentication, or registration screens.
• Implementing security passcodes, transaction authorization PINs, or parental control inputs.
• Hooking native SMS autofill on iOS (QuickType) and Android (SMS Retriever API or SMS User Consent API).
• Constructing in-app numeric keypads or custom PIN entry sheets without native soft keyboards.
• Auditing existing Flutter OTP implementations for controller leaks, rebuild bottlenecks, layout overflows, or accessibility gaps.

When NOT to Use

• Standard single-line or multi-line text input fields (use framework TextField or TextFormField).
• Continuous credit card numbers with formatted separators (use standard TextField with custom TextInputFormatters).
• Non-Flutter applications or backend OTP verification logic.