# Happy

An open-source desktop app for developers to orchestrate Claude, Codex, and Grok.

- Findings24: <https://findings24.com/products/happy>
- Website: <https://happy.engineering>
- Pricing: Freemium
- Categories: AI Agent Infrastructure, AI Developer Tools

## What is Happy?

Happy is an open-source desktop harness for coding agents. It brings Claude, Codex, and Grok into one app, using the model subscriptions and CLI sign-ins already on your computer. Agents run on your own hardware, and projects remain ordinary folders.

The app coordinates work across models, subagents, and sessions. Its mobile companion lets you continue sessions away from your desk, while remote agents and shared team servers support work across machines and collaborators.

## What can Happy do?

### Native model tools and shared conversations

Claude uses Claude Code's prompts and tools, GPT models use Codex's, and Grok uses Grok Build's. Switching models preserves the conversation transcript.

### Agent orchestration

Agents can delegate to subagents on any supported model and message one another. Scheduled messages and persistent bots support ongoing tasks.

### Durable sessions and isolated workspaces

Conversations and subagents survive closed windows and restarts with their context intact. Parallel work gets separate Git worktrees and branches.

### Permissions and sandboxing

In Auto mode, reads and workspace edits run freely. Other actions use an operating-system sandbox, with actions that cross its boundary reviewed automatically.

### Conversational setup

The Chief of Staff bot can add model accounts, import projects, pair a phone, deploy a remote agent, create a team, and upgrade Happy.

### Skills and MCP configuration

Happy supports skills defined in Markdown files and MCP configuration through TOML entries. Agents can write both.

## Use Cases

### Split development work across agents

Assign separate frontend and backend tasks to agents, choose models for each task, and keep parallel changes on separate branches.

### Continue work away from your desk

Use the phone app to access the same coding sessions while away from your computer. Messages between devices are end-to-end encrypted; the relay carries ciphertext only.

### Collaborate on shared projects

Run a Happy Agent for a team so members can share projects and sessions while each uses their own sign-in.

### Keep a terminal-based workflow

Start Claude Code or Codex through the Happy CLI and resume the session from your phone without installing the desktop app.

## Frequently Asked Questions

### What does Happy cost?

Happy is free and MIT licensed; model access uses your existing Claude, Codex, and Grok subscriptions. Phone voice includes 20 free minutes per 30 days. An in-app subscription provides up to 5 hours per 30 days. With your own ElevenLabs agent, Happy imposes no voice limit.

### How do I connect my model accounts?

Install and open the desktop app. Happy starts its own agent runtime and picks up Claude Code, Codex, and Grok CLI sign-ins on the machine. A Happy account is not required for model access.

### Is the original Happy CLI still supported?

The original CLI, published as happy on npm and formerly called happy-coder, is in maintenance mode. It continues to work and receives critical fixes, while new features ship in the desktop app. The mobile app works with both.

## Quick Facts

- **Product type**: Coding-agent harness
- **Desktop platforms**: macOS, Windows, Linux
- **License**: MIT
- **Website**: https://happy.engineering