/dev-commands

title: Development Commands
icon: code

Development Commands

:::info This document covers the core development commands for building, running, and previewing the eIsland application. For environment setup and prerequisites, see [Frontend Setup](/developer/environment-setup/frontend-setup.md). :::

All commands are run from the `web/` directory:

cd web
npm run <script>

`npm run dev`

Starts the application in development mode with hot reload.

npm run dev

**Under the hood:**

| Step | Process | Output | |------|---------|--------| | 1 | Compiles `src/main/` with electron-vite | `out/main/` | | 2 | Compiles `src/preload/` with electron-vite | `out/preload/` | | 3 | Starts Vite dev server for `src/renderer/` | `http://localhost:5173` | | 4 | Launches Electron pointing at the dev server | Desktop window |

:::tip The renderer uses **React Fast Refresh** — component state is preserved across edits. Main process changes trigger an automatic Electron restart. :::

**Common issues:**

| Problem | Cause | Solution | |---------|-------|----------| | Port 5173 in use | Another process is occupying the port | `netstat -ano \| findstr :5173` then `taskkill /PID <pid> /F` | | White screen | Renderer dev server not ready | Wait a few seconds; Vite needs time to bundle on first run | | Native module errors | Modules not rebuilt for Electron | Run `npx electron-builder install-app-deps` |

`npm run build`

Builds all three targets (main, preload, renderer) into the `out/` directory.

npm run build

**Output structure:**

out/
├── main/          # Compiled main process (Node.js)
├── preload/       # Compiled preload scripts
└── renderer/      # Compiled React UI (4 HTML entries)

:::info This command produces a production-ready build but does **not** create an installer. Use `npm run package` to produce a distributable `.exe` installer. See [Package Commands](package-commands.md). :::

**When to use:**

• Before running `npm run preview` to verify the production build
• When CI needs a clean build artifact
• To debug production-only issues locally

`npm run preview`

Previews the built application without the Vite dev server.

npm run preview

:::important You must run `npm run build` first. `npm run preview` serves the pre-built files from `out/` — it does not rebuild. :::

**When to use:**

• Verify the production build works correctly before packaging
• Debug issues that only appear outside of dev mode (e.g., CSP violations, missing assets)

Troubleshooting

`npm run dev` Fails to Start

**Port already in use:**

netstat -ano | findstr :5173
taskkill /PID <process-id> /F
npm run dev

**Native module errors:**

npx electron-builder install-app-deps
npm run dev

TypeScript Errors After Pull

rm -rf out/ node_modules/
npm install
npm run build