on — One command. Your entire dev environment.

See What Happens

One YAML config launches your entire workspace.

iTerm2 — myproject

api-server

$ watchexec -e py -- uv run python src/main.py dev

INFO: api server on 0.0.0.0:8080

INFO: watching for .py changes...

web-gateway

$ pnpm dev

ready - started server on 0.0.0.0:3001

compiled successfully in 0.8s

watching for file changes...

dashboard

$ pnpm dev

VITE v5.4.1 ready in 320ms

Local: http://localhost:5173/

myproject 0:api-server 1:web-gateway 2:dashboard 12:34

Auto-split terminal panes with running processes

Visual Studio Code — myproject (Workspace)

EXPLORER

MYPROJECT (WORKSPACE)

frontend

src

components

App.tsx

package.json

backend

main.py

routes

models.py

README.md

App.tsx frontend/src

main.py backend

1import { Router } from 'react-router'

2import { AuthProvider } from './auth'

4export default function App() {

5 return (

6 <AuthProvider>

7 <Router />

8 </AuthProvider>

9 )

10}

feat/auth TypeScript JSX UTF-8

VS Code opens in workspace mode with all project folders

Why `on`?

Terminal Panes

iTerm2 or tmux, auto split & name.

Smart Layouts

Vertical or grid, one line config.

Editor Integration

Auto-open VS Code / Cursor with workspace.

Browser Tabs

Auto-open all dev URLs.

Port Detection

Auto-detect port conflicts before launch.

Git Status

Warn about uncommitted changes before launch.

Get Started in Seconds

brew tap rickyshin93/tap

brew install rickyshin93/tap/on

Or build from source: cargo install --path .

Quick Start Config

~/.on/myproject.yaml

name: myproject

iterm: # or tmux

layout: vertical

panes:

- name: api-server

dir: ~/projects/myproject/api

cmd: watchexec -e py -- uv run python src/main.py dev

- name: web-gateway

dir: ~/projects/myproject/gateway

cmd: pnpm dev

- name: dashboard

dir: ~/projects/myproject/dashboard

cmd: pnpm dev

editor:

cmd: code

workspace: ~/.on/myproject.code-workspace

Run on new myproject to generate, then on myproject to launch.

on