Dart 3 modern features (through 3.10) and Effective Dart best practices including records, patterns, sealed classes, dot shorthands, null-aware collection elements, and wildcard variables. Use when adopting Dart 3.7+ syntax, using dot shorthands for enums or static members, using null-aware elements in lists or maps, using wildcard _ parameters, improving code quality, or reviewing Dart code conventions.

State management architecture for Flutter using Riverpod, Provider, and BLoC patterns. Use when choosing a state solution, implementing reactive state, resolving rebuild issues, or structuring MVVM/BLoC architecture.

Implements data visualization charts in Flutter using the fl_chart package (v1.3.1). Supports LineChart, BarChart, PieChart, ScatterChart, RadarChart, and CandlestickChart with implicit animations, touch interactivity, and pan/zoom transformations. Use when building any Flutter chart, graph, or data visualization — including line graphs for trends, bar charts for comparisons, pie/donut charts for proportions, scatter plots for distributions, radar charts for multi-axis comparisons, or candlestick charts for financial OHLC data. Also use when customizing chart axes, titles, tooltips, grid lines, touch callbacks, chart animations, or chart zoom/pan behavior.

Implements BLoC (v9.x) event-driven state management for Flutter with unidirectional data flow using the flutter_bloc package. Use when implementing Bloc/Cubit classes, mapping Events to States, consuming state with BlocBuilder/BlocListener/BlocConsumer, applying event transformers (restartable/droppable/sequential) for concurrency control, setting up BlocProvider/MultiBlocProvider DI, integrating Freezed for sealed union types and exhaustive pattern matching, or testing with blocTest. Ideal for enterprise apps requiring business logic separation, precise concurrency control (search debouncing, form deduplication), or event replay debugging.

Reads an OpenAPI 3.0 specification and manually implements a type-safe Dart API layer using Dio for HTTP, Freezed or Equatable for models, and json_serializable for serialisation. Use when given an OpenAPI/Swagger file (JSON or YAML) and asked to implement the API in Flutter/Dart, create Dart models from an API schema, build a Dio API client, implement endpoints from a spec, convert openapi to dart, or set up a data/network layer from an API contract. Handles $ref resolution, oneOf union types, enums, query params, request bodies, and DioException error mapping.

Firebase integration for Flutter including Auth, Firestore, FCM, Cloud Storage, Analytics, and Crashlytics. Use when implementing serverless backend features, real-time sync, or push notifications.

Integrates RevenueCat in-app purchases and subscriptions into Flutter apps using `purchases_flutter` (v11.x). Use when implementing paywalls, checking entitlements via `CustomerInfo`, configuring `PurchasesConfiguration` for iOS or Android, displaying paywalls with `purchases_ui_flutter`, handling purchase errors via `PurchasesErrorHelper`, restoring purchases, integrating RevenueCat with Riverpod or Bloc, presenting the Customer Center, handling web purchase redemption, or calling `Purchases.logIn` for cross-device purchase sync.

Integrates Sentry error tracking and performance monitoring into Flutter apps using `sentry_flutter`. Use when setting up crash reporting in Flutter, calling `SentryFlutter.init`, adding `SentryNavigatorObserver` to GoRouter, tracing HTTP requests with `sentry_dio`, capturing handled exceptions via `Sentry.captureException`, adding breadcrumbs, configuring session replay (`replay.onErrorSampleRate`), tuning `tracesSampleRate` or `profilesSampleRate`, controlling PII with `sendDefaultPii`, or setting user context after login and logout.

Supabase Flutter integration for PostgreSQL, Auth, Realtime subscriptions, Storage, Edge Functions, and Row Level Security. Use when building backend features with supabase_flutter or configuring database policies.

Provider (v6.x) state management for Flutter using ChangeNotifier and InheritedWidget with MVVM architecture pattern. Use this skill when implementing Provider-based state management, using Consumer/Consumer2 widgets for targeted rebuilds, accessing state with context.read/context.watch/context.select, setting up ChangeNotifierProvider or StateNotifierProvider, configuring MultiProvider for multiple providers, implementing ProxyProvider for dependent state, using Selector for optimized rebuilds, migrating from StatefulWidget to reactive state, maintaining legacy Provider codebases, debugging provider not found errors, preventing memory leaks with proper ChangeNotifier disposal, fixing context access issues in initState, or resolving .value constructor anti-patterns. Essential for apps with shared state across widgets (shopping carts, authentication, global settings, form state, theme management), when teaching state management fundamentals, or when debugging memory leaks and resource cleanup in Provider-based applications.

SharedPreferences (v2.5.5) for Flutter providing simple persistent key-value storage for non-sensitive user settings and app preferences. Use this skill when storing user preferences (theme mode, language selection, font size), app settings and configuration, feature flags or A/B test assignments, simple cache data, onboarding completion status, last selected values (filters, sort options), user consent flags, or any non-sensitive data that survives app restarts. Supports String, int, double, bool, and StringList types. NOT suitable for storing tokens, passwords, API keys, or any sensitive/encrypted data (use flutter_secure_storage instead). Ideal for quick persistent storage without database overhead.

Implements type-safe reactive SQL persistence in Flutter using Drift v2.32 (formerly Moor) built on SQLite with automatic code generation. Activates when defining table schemas with Drift DSL, writing type-safe join or subquery operations, handling schema migrations with MigrationStrategy, using reactive watch() streams for live UI updates, implementing ACID transactions, defining foreign key constraints or cascade deletes, enabling WAL mode for write performance, troubleshooting generated .g.dart type mismatches, migrating from sqflite or sqlite3 v2 to v3, using DAOs for query separation, or building offline-first apps requiring strong relational data integrity and compile-time SQL verification.

AI-driven Flutter E2E testing with Marionette (marionette_flutter in the app, marionette_cli or marionette_mcp to drive it). Control running Flutter apps in debug mode for smoke tests, regression checks, exploratory testing, and UI automation. Trigger when the user mentions E2E testing, UI automation, smoke tests, controlling a running Flutter app, VM Service interaction, tapping or entering text in an app, screenshots, log collection, session reports, or testing native dialogs, permissions, or WebViews. Supports named instances, direct VM service URIs, and MCP. Use for troubleshooting flaky UI flows, automating repetitive manual tests, verifying behavior after merges, and AI-agent-driven QA.

Manages local UI state and side effects in Flutter using the flutter_hooks package (v0.21.x) with HookWidget, useState, useEffect, useMemoized, useAnimationController, and custom hooks. Use this skill when replacing StatefulWidget boilerplate with hooks, reusing stateful UI logic across widgets, managing controller lifecycles (TextEditingController, AnimationController, ScrollController) without manual dispose, implementing countdown timers or subscriptions in widgets, mixing flutter_hooks with Riverpod via HookConsumerWidget, or any time the words 'flutter hooks', 'useEffect', 'useState', 'HookWidget', or 'flutter_hooks' appear in the request.