Bitwarden Android implementation patterns skill for Claude Code. Provides critical patterns, gotchas, anti-patterns, and copy-pasteable templates unique to the Bitwarden Android codebase.

Features

ViewModel SAE Pattern - State-Action-Event with BaseViewModel, SavedStateHandle persistence, process death recovery
Type-Safe Navigation - @Serializable routes, composableWithSlideTransitions, NavGraphBuilder/NavController extensions
Screen/Compose - Stateless composables, EventsEffect, remember(viewModel) lambda patterns
Data Layer - Repository pattern, DataState<T> streaming, Result sealed classes, Flow collection via Internal actions
UI Components - Bitwarden component library usage, theming, string resources
Security Patterns - Zero-knowledge architecture, encrypted storage, SDK isolation
Testing Patterns - ViewModel, repository, compose, and data source test structure
Clock/Time Handling - Clock injection for deterministic time operations

Skill Structure

implementing-android-code/
├── SKILL.md          # Quick reference for patterns, gotchas, and anti-patterns
├── templates.md      # Copy-pasteable code templates for all layer types
├── README.md         # This file
├── CHANGELOG.md      # Version history
└── CONTRIBUTING.md   # Contribution guidelines

Usage

Claude triggers this skill automatically when conversations involve implementing features, screens, ViewModels, data sources, or navigation in the Bitwarden Android app.

Example trigger phrases:

"How do I implement a ViewModel?"
"Create a new screen"
"Add navigation"
"Write a repository"
"BaseViewModel pattern"
"State-Action-Event"
"type-safe navigation"
"Clock injection"

Content Summary

Section	Description
A. ViewModel Implementation	SAE pattern, `handleAction`, `sendAction`, `SavedStateHandle`
B. Type-Safe Navigation	`@Serializable` routes, transitions, `NavGraphBuilder` extensions
C. Screen Implementation	Stateless composables, `EventsEffect`, action lambdas
D. Data Layer	Repositories, data sources, `DataState`, error handling
E. UI Components	Bitwarden component library, theming, string resources
F. Security Patterns	Zero-knowledge, encrypted storage, SDK isolation
G. Testing Quick Reference	ViewModel, repository, compose, data source tests
H. Clock/Time Patterns	`Clock` injection, deterministic time testing

References

docs/ARCHITECTURE.md - Comprehensive architecture patterns and examples
docs/STYLE_AND_BEST_PRACTICES.md - Code style, formatting, Compose conventions

Contributing

See CONTRIBUTING.md for development guidelines, versioning, and pull request requirements.

Changelog

See CHANGELOG.md for version history.

License

This skill is part of the Bitwarden Android project and follows its licensing terms.

Maintainers

Bitwarden Android team

Support

For issues or questions, open an issue in the bitwarden/android repository.