Happy is a revolutionary free, open-source mobile and web client for Claude Code that enables developers to control Claude AI from anywhere with intelligent voice commands, end-to-end encryption, and seamless workflow integration. Born from the frustration of not being able to check on AI coding tools while away from the keyboard, Happy brings the full power of Claude Code to your mobile device.

The project consists of three interconnected components: the Happy mobile app (iOS, Android, Web), Happy CLI for connecting local Claude Code to mobile devices, and Happy Server for secure synchronization. All components are MIT licensed and fully open source, making it accessible to developers worldwide.

Core Features

1. Cross-Platform Mobile Access

Continue the same Claude Code session seamlessly across iOS, Android, and Web platforms. Happy brings the complete Claude Code experience to mobile devices with an interface optimized for touch and voice interaction, allowing you to spawn and control multiple Claude Code instances in parallel from your phone and desktop.

2. Intelligent Voice Commands

Go beyond simple dictation with AI-powered voice commands that understand coding context and execute actions in real-time. The voice interface acts as an intelligent intermediary between you and Claude Code, processing natural language input, maintaining conversational context, and generating structured prompts for immediate execution. Code, debug, and manage projects completely hands-free.

3. End-to-End Encryption

Your code and conversations are protected with military-grade encryption using the same protocol as Signal (TweetNaCl). All messages are encrypted before leaving your device, ensuring complete privacy and security. The Happy Server passes encrypted messages between devices but cannot read your data, maintaining zero-knowledge architecture.

4. Real-Time Synchronization

The Happy Server provides secure synchronization that enables multiple devices to share encrypted conversations while maintaining complete privacy. Work seamlessly across mobile, web, and desktop with instant updates. Support for multiple concurrent Claude Code sessions with independent state management allows sessions to be paused, resumed, and switched between effortlessly.

5. Smart Notifications

Get alerted when your input is needed, when code is ready to review, or when something went wrong. Stay connected to your development workflow even when away from your desk, enabling you to review code, respond to issues, or make quick fixes on the go.

6. Complete Feature Parity

Access all Claude Code features on mobile - from plan mode to custom agents, skills system, and MCP server support. The mobile experience isn't limited; it's the full Claude Code power in your pocket.

Installation & Quick Start

Step 1: Install Happy CLI

npm install -g happy-coder

Step 2: Download the Mobile App

iPhone/iPad: Download from App Store
Android: Download from Google Play
Web App: Access at app.happy.engineering

Step 3: Start Your First Session

happy

This will start a Claude Code session, display a QR code, and enable real-time session sharing between Claude Code and your mobile app.

Step 4: Connect Your Mobile Device Scan the QR code displayed in your terminal to connect instantly.

System Requirements

Node.js: Version 18 or later (released April 19, 2022)
Claude CLI: Must be installed and logged in (claude command available in PATH)
Operating Systems: macOS, Linux, Windows (via WSL)
Mobile Devices: iOS 14+, Android 8+, or modern web browser

Real-World Use Cases

Mobile Development Workflow One developer shared: "In line at TSA pre-check, I finished another 20% of a magic link app. On the plane, waiting to depart, I deployed it to AWS and made some final DynamoDB schema changes. By the time I returned to NYC, the app was live in Prod."

Code Review on the Go Review pull requests, check on AI assistant progress, and respond to critical issues during coffee breaks, commutes, or while traveling.

Voice-First Coding Use natural language voice commands for hands-free coding sessions, perfect for brainstorming, debugging, or working in environments where typing isn't convenient.

Project Components

Component	Description	Repository
Happy	Main mobile and web client application with voice and encryption support	github.com/slopus/happy
Happy CLI	Command line tool to connect local Claude Code to mobile devices	github.com/slopus/happy-cli
Happy Server	Secure synchronization backend for multi-device support with E2E encryption	github.com/slopus/happy-server

Privacy & Security

Happy is built with privacy as a core principle:

Zero Knowledge Architecture: Server cannot read your messages or code
End-to-End Encryption: Same encryption protocol as Signal (TweetNaCl)
Local Processing: Claude Code runs on your hardware
No Vendor Lock-in: Fully open source, MIT licensed
Transparent Security: All code is auditable on GitHub

Community & Support

Happy is actively maintained by slopus and the open-source community. Community feedback highlights the tool's effectiveness: "Nothing beats github.com/slopus/happy with Claude Code" according to developer reviews.

Get Involved:

Report issues on GitHub
Contribute to the open-source project
Join discussions on Hacker News
Follow updates at happy.engineering

Comparison with Alternatives

Feature	Happy	Standard Claude Code	Other Mobile Clients
Mobile Access	✅ Full support	❌ Desktop only	⚠️ Limited
Voice Commands	✅ Intelligent AI	❌ Not available	❌ Not available
E2E Encryption	✅ Signal-grade	⚠️ HTTPS only	⚠️ Varies
Cross-Device Sync	✅ Real-time	❌ Not available	⚠️ Limited
Open Source	✅ MIT License	⚠️ Proprietary CLI	⚠️ Varies
Cost	✅ Free	✅ Free CLI	⚠️ Often paid
Multiple Sessions	✅ Parallel support	✅ Yes	❌ Usually single
Offline Capability	⚠️ Requires connection	⚠️ Requires API	⚠️ Varies

Advantages & Unique Selling Points

Compared to Desktop-Only Solutions:

True Mobility: Work from anywhere - coffee shops, airports, commutes, or vacations
Voice-First Interface: Hands-free coding that understands context, not just dictation
Always Connected: Stay in sync with your projects without being chained to a desk

What Makes Happy Stand Out:

First truly mobile-optimized Claude Code client with full feature parity
Military-grade encryption ensuring complete privacy and security
Intelligent voice commands that go far beyond basic speech-to-text
Completely free and open source with no vendor lock-in
Active development and responsive community support
Parallel session management for complex multi-project workflows

Tips & Best Practices

Use Voice for Brainstorming: Voice commands excel for high-level planning and architectural discussions before diving into code
Enable Push Notifications: Stay informed about build status, test results, and when your input is needed
Set Up Multiple Sessions: Use parallel sessions for different projects or experimental features
Review Before Committing: Always review code changes on mobile before pushing to production
Leverage Plan Mode: Use Claude Code's plan mode on mobile for strategic decisions and implementation planning
Secure Your Device: Since everything is encrypted, your device password is your primary security layer

Frequently Asked Questions

Q: Is Happy secure for sensitive codebases? A: Yes, Happy uses the same encryption protocol as Signal (TweetNaCl) with end-to-end encryption. The server cannot read your messages or code, maintaining zero-knowledge architecture.

Q: Does Happy work offline? A: Happy requires an internet connection to sync with Claude Code and the Happy Server. However, you can review previous conversations offline.

Q: What's the difference between Happy CLI and Happy mobile app? A: Happy CLI runs on your computer and connects local Claude Code to the Happy ecosystem. The mobile app provides the touch and voice interface for controlling Claude Code from your phone.

Q: Can I use Happy with multiple Claude Code accounts? A: Yes, you can manage multiple sessions and switch between them seamlessly on the mobile app.

Q: Is there a cost to use Happy? A: No, Happy is completely free and open source under the MIT license. You only pay for your Claude API usage.

Q: How does Happy handle voice commands? A: Happy's AI-powered voice interface processes natural language, understands coding context, maintains conversational state, and generates structured prompts for Claude Code execution in real-time.

Conclusion

Happy represents a paradigm shift in how developers interact with AI coding assistants, breaking free from desktop constraints to enable truly mobile-first development workflows. With intelligent voice commands, military-grade encryption, and seamless cross-device synchronization, Happy empowers developers to stay productive anywhere.

Whether you're reviewing code during your commute, debugging in a coffee shop, or deploying to production from an airport lounge, Happy brings the full power of Claude Code to your fingertips. Best of all, it's completely free, open source, and built with privacy as a core principle.

Ready to code from anywhere? Install Happy today and experience the future of mobile AI-assisted development.

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