Happy: Mobile and Desktop Client for Claude Code
Happy is an open-source app and CLI that wraps Claude Code and Codex so you can continue sessions from your phone with end-to-end encryption. Install, uses.
By Claudekit Team Published 1 min read
- Type
- App
- Pricing
- Open Source
- Repository
- github.com
- GitHub stars
- 24,288
- Website
- happy.engineering
Happy is a free, open-source (MIT) client for coding agents. Its original CLI wraps Claude Code and Codex in your terminal and mirrors the session to an iOS, Android or web app, so you can check progress, answer prompts and keep steering from your phone. The newer desktop app (“Happy Harness”) orchestrates Claude, Codex and Grok in one place and adds multiplayer sessions.
Who it is for
Developers who start long Claude Code tasks and want to approve permissions or redirect the agent while away from their desk, and small teams who want to watch and steer the same agent together.
Install
The original CLI:
npm install -g happy
# Start Claude Code
happy claude
# Or start Codex
happy codexThen install the mobile app from the App Store or Google Play, or use the web client, and pair it with your session. Desktop builds for macOS, Windows and Linux are linked from happy.engineering.
Use cases
- Kick off a refactor, leave for lunch, and approve the next permission prompt from your phone.
- Monitor a long test-fixing loop and stop it if it goes off track.
- Invite a colleague into a session to pair on a tricky bug.
- Mix models in one desktop workspace and delegate subtasks across them.
Pros
- Reuses existing subscriptions; no extra AI bill.
- End-to-end encrypted sync between devices.
- Open source across app, CLI and relay server; self-hostable.
Cons and caveats
- Wrapping official CLIs means features can lag behind new Claude Code releases.
- Remote approval makes it easy to say yes without reading diffs closely; stay careful with permissions.
- The project is split across several repos (app, desktop, agent runtime), so docs are spread out.
- The package moved from
happy-codertohappy; older guides use the old name.
Links
- Repo: slopus/happy
- Website and docs: happy.engineering
- Related: Claude Code, permission modes, Claude Squad
Frequently asked questions
Does Happy need its own AI subscription?
No. The project says you sign in with the Claude, Codex or Grok subscriptions you already pay for; Happy adds a harness, not another bill.
Is my code sent to Happy's servers?
Sessions run on your own hardware. Sync between devices goes through a relay server and is end-to-end encrypted, per the README.
What is the difference between the CLI and the desktop app?
The original happy CLI wraps Claude Code or Codex in your terminal for phone access. The desktop app and Happy Harness add multi-model sessions and teams.