Any Model. Your Subscription.
Happy Harness.
Free and open source
https://github.com/user-attachments/assets/b3580704-f9e0-441e-80be-3f83f6a08ab5
What you get
- Multi-provider within one session. Astra, Fable, and Grok in the same session. Switch models in the middle of a task or delegate to subagents.
- Reuse current subscriptions. Sign in with the Claude, Codex, and Grok plans you already pay for. 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.
Resources
Website · Documentation · Discord · Development guide · MIT License
How Happy fits together
| 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 |
Original Happy CLI
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 (
happyon 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!