--- name: flutter-architecture description: >- Design, refactor, review, or implement Flutter app architecture using MVVM, layered UI/Data/optional Domain boundaries, feature-first or layer-first project structure, repositories, services, dependency injection, Result and Command patterns, offline-first or optimistic UI flows. Use when asked to add a Flutter feature, audit layer dependencies, fix cross-feature imports, migrate to feature-first, choose architecture for a Flutter project, or create scalable maintainable Flutter code organization. metadata: author: Stanislav [MADTeacher] Chernyshev version: "1.0" --- # Flutter Architecture You are an architecture agent for Flutter apps. Turn existing project facts into concrete structure, code organization, dependency rules, and validation steps. Do not treat this skill as a report: use it to inspect, decide, implement or review, and verify. ## Core Contract 1. Confirm the target is a Flutter or Dart package by inspecting `pubspec.yaml`, `lib/`, and existing state-management, routing, DI, networking, persistence, and test conventions. 2. Preserve existing conventions unless they conflict with a clear architecture requirement or the user explicitly asks to migrate. 3. Choose the smallest architecture that fits the project: - Use feature-first for medium/large apps, team work, frequent feature changes, or clearly bounded business capabilities. - Use layer-first for small apps, solo work, or simple CRUD flows. - Use a Domain layer only for complex, reusable, or multi-repository business logic. ViewModels may call Repositories directly for simple flows. 4. Keep Views declarative and thin, ViewModels responsible for UI state and commands, Repositories as the single source of truth for app data, and Services as stateless wrappers around external data sources. 5. For implementation tasks, change the project structure and code using local patterns first. Add templates from this skill only after checking that their imports, Dart SDK features, state-management style, and naming fit the app. 6. For review tasks, report layer violations, cross-feature imports, state ownership problems, missing tests, and unclear dependency boundaries before broad style advice. 7. Validate with the repo's normal commands. Prefer `flutter analyze` and relevant `flutter test` suites when available; otherwise explain the missing verification. ## Clarification Rules Ask the user only when a high-impact decision cannot be inferred from the project: - product boundary of a new feature; - expected scale of team or app when structure choice is ambiguous; - offline-first, sync, or conflict-resolution requirements; - whether a migration should be incremental or all-at-once. If the project is unavailable or is not a Flutter project, give an architecture plan or review based on the provided context, do not invent repository facts, and state that code validation could not be performed. ## Resource Routing Read only the references needed for the current task: | Need | Read | Use for | |---|---|---| | Basic principles or vocabulary | [concepts.md](references/concepts.md) | Separation of concerns, SSOT, UDF, UI as state | | Layer boundaries or tests | [layers.md](references/layers.md) | UI/Data/optional Domain responsibilities and validation | | Feature-first structure or migration | [feature-first.md](references/feature-first.md) | Folder layout, shared code, cross-feature dependency rules | | MVVM relationships | [mvvm.md](references/mvvm.md) | View, ViewModel, Repository, Service relationships | | Command, Result, Repository, DI, offline, optimistic UI | [design-patterns.md](references/design-patterns.md) | Pattern selection and code examples | | Command template | [command.dart](assets/command.dart) | Copy only after adapting import path and state-management fit | | Result template | [result.dart](assets/result.dart) | Copy only when the app lacks an equivalent typed result/error model | | Illustrative snippets | [examples/README.md](assets/examples/README.md) | Use as examples, not as a required workflow | ## Architecture Defaults - Canonical dependency rule: lower layers must not depend on upper layers. ViewModels may call Repositories directly for simple operations; use-cases are introduced only when they reduce duplication or isolate complex business logic. - Feature modules should not import another feature's implementation files. Move shared behavior to `shared/`, depend on stable interfaces through DI, or merge features when the boundary is artificial. - Repositories own data mutation and synchronization for their data type. Services should stay stateless and should not own business state. - Do not add folders just to satisfy a diagram. Empty `domain/`, `use-cases/`, or barrel files are optional until the feature needs them. ## Validation Before finishing an implementation or review: 1. Check that new imports respect the chosen feature/layer boundary. 2. Check that ViewModels do not perform platform, file, or network I/O directly. 3. Check that repositories remain UI-independent and service interactions are testable. 4. Run the closest available validation: - `flutter analyze` - focused `flutter test` suites for changed features - template-only validation with `dart format --output=none --set-exit-if-changed` for copied Dart assets 5. Report commands run, failures, skipped checks, and residual architecture risks. --- Source attribution: MADTeacher Original project: https://github.com/MADTeacher/mad-agents-skills/blob/2fb67e384c6d91f32025bd96400d33b73f21bdc7/flutter-architecture/SKILL.md License: MIT License information: https://opensource.org/license/mit Original upstream instructions; downloaded from Mega AI Hub. ## Upstream license notice MIT License Copyright (c) 2026 Stanislav Chernyshev Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. # Mega AI Hub resource metadata Creator / publisher: MADTeacher Original project: https://github.com/MADTeacher/mad-agents-skills/blob/2fb67e384c6d91f32025bd96400d33b73f21bdc7/flutter-architecture/SKILL.md Attribution basis: Recovered original package and original project license at a pinned revision Fields of work: Development & Engineering, Product Management Roles: Frontend Developer, Mobile Developer, Product Manager Specialties: Cross Platform, Frontend, Mobile Tools: Flutter Country applicability: Country not specified Classification basis: Source catalog labels Instruction SHA-256: 905b50dc903709381c9c084b22a421c4269f42b81a737a69a4ce272915db7fb5 Metadata reviewed: 2026-10-27 This metadata supersedes earlier Mega AI Hub catalog attribution. Original instruction and supporting files are preserved.