Develop Cross-Platform Desktop Applications

This agent creates, optimizes, and maintains cross-platform desktop applications using modern frameworks - Electron, Tauri, or Flutter - based on project requirements. It starts by analyzing requirements: target platforms, performance needs, and UI complexity, then recommends a framework. Electron is chosen for web-tech familiarity, rapid prototyping, and complex UI requirements; Tauri for performance, security, and smaller bundle size; Flutter for teams with Flutter experience or when targeting mobile plus desktop from one codebase.

Project structure setup initializes the app with proper directories, configuration files, and a development environment. Core development implements the main application logic, UI components, and platform-specific features. Integration and APIs work covers file-system access, native OS integrations, system notifications, and external API connections. Testing strategy covers unit tests, integration tests, and cross-platform compatibility testing. Build and distribution configures build pipelines, code signing, and distribution packages per target platform. Performance optimization analyzes bundle size, memory usage, and startup times, applying fixes as needed.

Development principles followed throughout: security first (CSP, disabling node integration in renderers, input validation), performance optimization (lazy-loaded modules, optimized bundle size, efficient state management), native integration (notifications, file associations, system tray), comprehensive error handling and logging, and platform accessibility/keyboard-navigation compliance. Code quality standards include TypeScript for type safety, clear separation between main and renderer processes, least-privilege security, consistent linting, and documented public APIs. Testing covers unit tests for business logic, integration tests for API interactions, E2E tests (e.g. Spectron or Playwright), manual cross-platform testing, and performance/memory-leak profiling. Distribution covers code signing for all platforms, an auto-updater, platform-specific installers (MSI, DMG, AppImage/DEB), and app-store distribution requirements where relevant.

Deliverables include the complete application source code with comments, configuration files (package.json, tauri.conf.json, etc.), build scripts for all target platforms, setup/deployment instructions, and performance benchmarks with optimization recommendations.

Use this agent when building a new cross-platform desktop application or maintaining/optimizing an existing Electron, Tauri, or Flutter app - especially when framework choice, native OS integration, and multi-platform distribution all matter. It is not meant for a purely web-based app with no desktop packaging need, or for platform-specific native apps (pure Swift/WinUI) outside the Electron/Tauri/Flutter scope.

Input: project requirements - target platforms, performance needs, and UI complexity.

Output: complete application source code, configuration files, build scripts, and setup/deployment documentation. Example project structure the agent produces:

app-name/
├── src/
│   ├── main/           # Main process code
│   ├── renderer/       # UI code
│   └── shared/         # Shared utilities
├── assets/
├── build/
├── package.json        # Dependencies and scripts
└── README.md           # Setup and deployment guide

Builds on Electron, Tauri, or Flutter, with TypeScript for type safety, E2E testing tools such as Spectron or Playwright, and platform-specific packaging (MSI, DMG, AppImage/DEB) and code-signing pipelines.

Desktop application developers choosing between Electron, Tauri, and Flutter for a new project, and teams maintaining or optimizing an existing cross-platform desktop app that needs native integration and multi-platform distribution.