The `bun` CLI contains a Node.js-compatible package manager designed to be a dramatically faster replacement for `npm`, `yarn`, and `pnpm`. It's a standalone tool that will work in pre-existing Node.js projects; if your project has a `package.json`, `bun install` can help you speed up your workflow.

{% callout %}

**⚡️ 25x faster** — Switch from `npm install` to `bun install` in any Node.js project to make your installations up to 25x faster.

{% image src="https://user-images.githubusercontent.com/709451/147004342-571b6123-17a9-49a2-8bfd-dcfc5204047e.png" height="200" /%}

{% /callout %}

{% details summary="For Linux users" %}
The minimum Linux Kernel version is 5.1. If you're on Linux kernel 5.1 - 5.5, `bun install` should still work, but HTTP requests will be slow due to a lack of support for io_uring's `connect()` operation.

If you're using Ubuntu 20.04, here's how to install a [newer kernel](https://wiki.ubuntu.com/Kernel/LTSEnablementStack):

```bash
# If this returns a version >= 5.6, you don't need to do anything
uname -r

# Install the official Ubuntu hardware enablement kernel
sudo apt install --install-recommends linux-generic-hwe-20.04
```

{% /details %}

To install all dependencies of a project:

```bash
$ bun install
```

Running `bun install` will:

- **Install** all `dependencies`, `devDependencies`, and `optionalDependencies`. Bun does not install `peerDependencies` by default.
- **Run** your project's `{pre|post}install` and `{pre|post}prepare` scripts at the appropriate time. For security reasons Bun _does not execute_ lifecycle scripts of installed dependencies.
- **Write** a `bun.lockb` lockfile to the project root.

## Logging

To modify logging verbosity:

```bash
$ bun install --verbose # debug logging
$ bun install --silent  # no logging
```

## Lifecycle scripts

Unlike other npm clients, Bun does not execute arbitrary lifecycle scripts like `postinstall` for installed dependencies. Executing arbitrary scripts represents a potential security risk.

To tell Bun to allow lifecycle scripts for a particular package, add the package to `trustedDependencies` in your package.json.

```json-diff
  {
    "name": "my-app",
    "version": "1.0.0",
+   "trustedDependencies": ["my-trusted-package"]
  }
```

Then re-install the package. Bun will read this field and run lifecycle scripts for `my-trusted-package`.

## Workspaces

Bun supports `"workspaces"` in package.json. For complete documentation refer to [Package manager > Workspaces](/docs/install/workspaces).

```json#package.json
{
  "name": "my-app",
  "version": "1.0.0",
  "workspaces": ["packages/*"],
  "dependencies": {
    "preact": "^10.5.13"
  }
}
```

## Overrides and resolutions

Bun supports npm's `"overrides"` and Yarn's `"resolutions"` in `package.json`. These are mechanisms for specifying a version range for _metadependencies_—the dependencies of your dependencies. Refer to [Package manager > Overrides and resolutions](/docs/install/overrides-and-resolutions) for complete documentation.

```json-diff#package.json
  {
    "name": "my-app",
    "dependencies": {
      "foo": "^2.0.0"
    },
+   "overrides": {
+     "bar": "~4.4.0"
+   }
  }
```

## Global packages

To install a package globally, use the `-g`/`--global` flag. Typically this is used for installing command-line tools.

```bash
$ bun install --global cowsay # or `bun install -g cowsay`
$ cowsay "Bun!"
 ______
< Bun! >
 ------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||
```

## Production mode

To install in production mode (i.e. without `devDependencies` or `optionalDependencies`):

```bash
$ bun install --production
```

For reproducible installs, use `--frozen-lockfile`. This will install the exact versions of each package specified in the lockfile. If your `package.json` disagrees with `bun.lockb`, Bun will exit with an error. The lockfile will not be updated.

```bash
$ bun install --frozen-lockfile
```

For more information on Bun's binary lockfile `bun.lockb`, refer to [Package manager > Lockfile](/docs/install/lockfile).

## Dry run

To perform a dry run (i.e. don't actually install anything):

```bash
$ bun install --dry-run
```

## Non-npm dependencies

Bun supports installing dependencies from Git, GitHub, and local or remotely-hosted tarballs. For complete documentation refer to [Package manager > Git, GitHub, and tarball dependencies](/docs/cli/add).

```json#package.json
{
  "dependencies": {
    "dayjs": "git+https://github.com/iamkun/dayjs.git",
    "lodash": "git+ssh://github.com/lodash/lodash.git#4.17.21",
    "moment": "git@github.com:moment/moment.git",
    "zod": "github:colinhacks/zod",
    "react": "https://registry.npmjs.org/react/-/react-18.2.0.tgz"
  }
}
```

## Configuration

The default behavior of `bun install` can be configured in `bunfig.toml`. The default values are shown below.

```toml
[install]

# whether to install optionalDependencies
optional = true

# whether to install devDependencies
dev = true

# whether to install peerDependencies
peer = false

# equivalent to `--production` flag
production = false

# equivalent to `--frozen-lockfile` flag
frozenLockfile = false

# equivalent to `--dry-run` flag
dryRun = false
```

## CI/CD

Looking to speed up your CI? Use the official [`oven-sh/setup-bun`](https://github.com/oven-sh/setup-bun) action to install `bun` in a GitHub Actions pipeline.

```yaml#.github/workflows/release.yml
name: bun-types
jobs:
  build:
    name: build-app
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repo
        uses: actions/checkout@v3
      - name: Install bun
        uses: oven-sh/setup-bun@v1
      - name: Install dependencies
        run: bun install
      - name: Build app
        run: bun run build
```