Happy Engineering

The fun way of making things :D

What you get

Any model: Claude, Codex, Grok, Gemini, and more. Gemini runs through Antigravity, and OpenCode or any Agent Client Protocol agent plugs in as a harness. Give every task the model that fits, and delegate to subagents on any of them.
Reuse your subscriptions. Sign in with the Claude, Codex, and Grok subscriptions you already pay for; Antigravity, OpenCode, and ACP agents keep their own logins. Happy adds a harness, not another bill.
Open source MIT. It runs on your own hardware and your projects stay ordinary folders. Read the code, fork it, ship your own build.
End-to-end encrypted mobile app. Left your desk? The same sessions are already on your phone, and what moves between your devices is encrypted.
Natively multiplayer. Invite a colleague or a friend into the session. You both watch the same agent work, and either of you can steer it.

Repository	What it is
slopus/happy ← this repository	The mobile app (iOS, Android, web), the original CLI, and the relay server
slopus/happy-desktop	The desktop app for macOS, Windows, and Linux
slopus/happy-agent	Happy Agent, the open-source agent runtime the desktop app runs on
slopus/slopus.github.io	The website and docs at happy.engineering

The original CLI wraps the Claude Code and Codex harnesses directly in your terminal and lets you continue from your phone.

For multi-model sessions and teams, move to the desktop app and Happy Harness.

npm install -g happy

# Start Claude Code
happy claude

# Or start Codex
happy codex

happy-app: the Happy mobile app and web client (Expo)
happy-cli: the original Happy CLI (happy on npm)
happy-agent: remote session control for the original Happy CLI (not the Happy Agent runtime)
happy-server: the relay server for encrypted sync

Migrated from the happy-coder package. Thanks to @franciscop for donating the happy package name!