Happy

Happy is a free, open-source mobile client for Claude Code with end-to-end encryption, push notifications, multiple sessions, and voice coding.

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What Happy is

Happy is a mobile client for Claude Code that lets you start and continue the same coding session from your computer, phone, or the web. It is designed for developers who want to keep working on agentic coding tasks without being tied to a desk.

The product runs as a CLI on your computer, a mobile app on your phone, and a relay server in between. The CLI starts Claude Code and encrypts session activity, the app shows that activity on mobile, and the relay only forwards encrypted data.

The site positions Happy as free and open source, with end-to-end encryption and support for multiple active sessions. It also adds quality-of-life features such as push notifications and voice coding for hands-free interaction.

Features

Real-time cross-device sync

Start a Claude Code session on your computer, then continue the same session from your phone or the web without a handoff. Both devices can send messages and receive responses in one shared session.

Multiple active sessions

Run more than one Claude Code session at once, each with its own project context and history. This lets you keep frontend, backend, and infrastructure work separate.

Claude Code workflow on mobile

See native mobile support for Claude Code actions such as file mentions, slash commands, and custom agents. The product is meant to mirror the terminal workflow on mobile instead of creating a separate chat experience.

Smart push notifications

Receive alerts when input is needed, when code is ready to review, or when something goes wrong. The push system is designed to surface important session events while you are away from the keyboard.

Voice coding with a translator

Use a voice agent to speak commands and translate rambling thoughts into structured requests for Claude Code. The docs emphasize voice-to-action execution rather than simple transcription.

End-to-end encrypted relay

Keep data encrypted end to end between the CLI, mobile app, and relay server. The server moves encrypted messages but cannot read the contents.

Use Cases

Move between desktop and phone
Start a Claude Code session at your desk, then keep following the same conversation on your phone while you move around. This works well when you want continuity without restarting or re-explaining context.
Handle multiple projects in parallel
Run separate Claude Code sessions for different codebases or workstreams. The product is built to keep project context isolated so you can switch without mixing conversations.
Stay responsive away from the desk
Use the phone app to review progress, answer prompts, and approve or deny actions when you are away from your computer. Push notifications help surface the moments that need attention.
Capture ideas hands-free
Talk through a refactor, prototype, or idea with the voice agent when typing is inconvenient. The docs frame this as a way to turn rough spoken thoughts into structured instructions for Claude Code.
Extend an existing development workflow
Keep using your normal terminal, editor, and Git workflow while Happy mirrors the Claude Code session to mobile. The site says it is designed to fit existing tools without changing how you work.

Pros and Cons

Pros

Keeps one Claude Code session available across mobile, desktop, and web.
Supports end-to-end encryption, with a relay server that cannot read plaintext.
Allows multiple concurrent sessions for different projects.
Adds push notifications for review requests and errors.
Includes voice coding for hands-free input when typing is inconvenient.

Cons

The pricing page is not available in the provided sources, so published plan details are unclear.
Voice coding is presented as useful, but the docs note that it is still inferior to typing for many tasks.

FAQ

How does Happy work across phone and computer?

Happy works by starting the `happy` CLI on your computer, which launches a Claude Code session that you can continue from iOS, Android, or the web. The CLI streams encrypted activity to a relay server, and the mobile app displays and sends back encrypted messages for the same session.

What does Happy cost?

The site describes Happy as free and open source, and the homepage says it costs nothing. The pricing page itself returns a 404, so there are no published plan details or prices on the site pages provided.

Who is Happy best suited for?

Happy is positioned for developers who want to keep using Claude Code away from their desk, including phone-first check-ins, commuting, and hands-free voice-driven coding. It keeps the same session available when you move between mobile and desktop.

What features are included?

The source says Happy supports real-time synchronization, multiple active sessions, smart push notifications, voice coding, and the same terminal features you would use in Claude Code, including plan mode and custom agents. The feature page also mentions file mentions, slash commands, and custom agents.

Is my code and conversation private?

The site says all communication is end-to-end encrypted and that the relay server only passes encrypted blobs. The mobile app and CLI share a session, but the server cannot read plaintext code or messages.

Quick Facts

Category: Developer Tool
Platform: iOS, Android, Web, Desktop CLI
Pricing: Free and open source; no published pricing details on the provided pages
Primary use: Mobile access to Claude Code sessions
Integration: Claude Code
Security: End-to-end encryption