# Source: https://rsbuild.dev/guide/basic/cli.md

# CLI

Rsbuild includes a lightweight CLI with commands like [rsbuild dev](#rsbuild-dev) and [rsbuild build](#rsbuild-build).

## All commands

To view all available CLI commands, run this command in your project directory:

```bash
npx rsbuild -h
```

The output is shown below:

```
Usage:
  $ rsbuild [command] [options]

Commands:
  dev      Start the dev server
  build    Build the app for production
  preview  Preview the production build locally
  inspect  Inspect the Rspack and Rsbuild configurations
```

## Common flags

The Rsbuild CLI includes several common flags that work with all commands:

| Flag                       | Description                                                                                                                                |
| -------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------ |
| `--base <base>`            | Set the base path of the server, see [server.base](/config/server/base.md)                                                                    |
| `-c, --config <config>`    | Set the configuration file (relative or absolute path), see [Specify config file](/guide/configuration/rsbuild.md#specify-config-file)        |
| `--config-loader <loader>` | Set the config file loader (`auto` | `jiti` | `native`), see [Specify config loader](/guide/configuration/rsbuild.md#specify-config-loader) |
| `--env-mode <mode>`        | Set the env mode to load the `.env.[mode]` file, see [Env mode](/guide/advanced/env-vars.md#env-mode)                                         |
| `--env-dir <dir>`          | Set the directory for loading `.env` files, see [Env directory](/guide/advanced/env-vars.md#env-directory)                                    |
| `--environment <name>`     | Set the environment name(s) to build, see [Build specified environment](/guide/advanced/environments.md#build-specified-environment)          |
| `-h, --help`               | Display help for command                                                                                                                   |
| `--log-level <level>`      | Set the log level (`info` | `warn` | `error` | `silent`), see [logLevel](/config/log-level.md)                                             |
| `-m, --mode <mode>`        | Set the build mode (`development` | `production` | `none`), see [mode](/config/mode.md)                                                     |
| `--no-env`                 | Disable loading of `.env` files                                                                                                            |
| `-r, --root <root>`        | Set the project root directory (absolute path or relative to [cwd](https://nodejs.org/api/process.html#processcwd))                        |

## rsbuild dev

The `rsbuild dev` command starts a local dev server and compiles source code for development.

```bash
Usage: rsbuild dev [options]

Options:
  -o, --open [url]      Open the page in browser on startup
  --port <port>         Set the port number for the server
  --host <host>         Set the host that the server listens to
```

Start the dev server by running `rsbuild` directly (equivalent to `rsbuild dev`):

```bash
npx rsbuild
```

### Opening page

The `--open` option opens a page automatically when the dev server starts (equivalent to setting [server.open](/config/server/open.md) to `true`).

```bash
rsbuild dev --open
```

The `--open` option also accepts a specific URL to open. For example:

```bash
rsbuild dev --open http://localhost:3000/foo
```

The `--open` option can also be abbreviated to `-o`:

```bash
rsbuild dev -o
```

:::tip
When using both [server.open](/config/server/open.md) and `--open`, the `--open` option takes precedence.
:::

## rsbuild build

The `rsbuild build` command builds production outputs in the `dist/` directory by default.

```bash
Usage: rsbuild build [options]

Options:
  -w, --watch           Enable watch mode to automatically rebuild on file changes
```

## rsbuild preview

The `rsbuild preview` command previews production build outputs locally. You must run `rsbuild build` first to generate the outputs.

```bash
Usage: rsbuild preview [options]

Options:
  -o, --open [url]      Open the page in browser on startup
  --port <port>         Set a port number for Rsbuild server to listen
  --host <host>         Set the host that the Rsbuild server listens to
```

:::tip
Use the preview command only for local previews. Do not use it in production, as it is not designed for production servers.
:::

## rsbuild inspect

The `rsbuild inspect` command displays the project's Rsbuild and Rspack configurations.

```bash
Usage: rsbuild inspect [options]

Options:
  --output <output>     Set the output path for inspection results (default: ".rsbuild")
  --verbose             Show complete function definitions in output
```

Running `npx rsbuild inspect` in the project root generates the following files in the `dist/.rsbuild` directory:

* `rsbuild.config.mjs`: Represents the Rsbuild configuration used during the build.
* `rspack.config.web.mjs`: Represents the Rspack configuration used during the build.

```bash
➜ npx rsbuild inspect

config inspection completed, generated files:

  - Rsbuild config: /project/dist/.rsbuild/rsbuild.config.mjs
  - Rspack config (web): /project/dist/.rsbuild/rspack.config.web.mjs
```

### Setting mode

By default, the inspect command outputs configuration for development mode. To output production mode configuration, add the `--mode production` option:

```bash
rsbuild inspect --mode production
```

### Verbose content

By default, the inspect command omits function bodies in the configuration object. To output complete function content, add the `--verbose` option:

```bash
rsbuild inspect --verbose
```

### Multiple targets

If the current project has multiple build targets (such as building both browser and Node.js bundles), multiple Rspack configuration files will be generated in the `dist/.rsbuild` directory.

```bash
➜ npx rsbuild inspect

config inspection completed, generated files:

  - Rsbuild config (web): /project/dist/.rsbuild/rsbuild.config.web.mjs
  - Rsbuild config (node): /project/dist/.rsbuild/rsbuild.config.node.mjs
  - Rspack config (web): /project/dist/.rsbuild/rspack.config.web.mjs
  - Rspack config (node): /project/dist/.rsbuild/rspack.config.node.mjs
```