---
title: "bun --filter"
description: "Select packages by pattern in a monorepo using the --filter flag"
---

The `--filter` (or `-F`) flag selects packages in a monorepo by pattern. Patterns match package names or package paths, with full glob syntax.

`bun install` and `bun outdated` support `--filter`, and you can use it to run scripts in multiple packages at once.

---

## Matching

### Package Name `--filter <pattern>`

Name patterns select packages by the `name` field in `package.json`. For example, if you have packages `pkg-a`, `pkg-b` and `other`, you can match all of them with `*`, only `pkg-a` and `pkg-b` with `pkg*`, and a specific package with its full name.

### Package Path `--filter ./<glob>`

Path patterns start with `./` and select all packages in directories matching the pattern. For example, to match all packages in subdirectories of `packages`, use `--filter './packages/**'`. To match the package in `packages/foo`, use `--filter ./packages/foo`.

---

## `bun install` and `bun outdated`

By default, `bun install` installs dependencies for every package in the monorepo. To install dependencies for specific packages, use `--filter`.

Given a monorepo with workspaces `pkg-a`, `pkg-b`, and `pkg-c` under `./packages`:

```bash terminal icon="terminal"
# Install dependencies for all workspaces except `pkg-c`
bun install --filter '!pkg-c'

# Install dependencies for packages in `./packages` (`pkg-a`, `pkg-b`, `pkg-c`)
bun install --filter './packages/*'

# Save as above, but exclude the root package.json
bun install --filter '!./' --filter './packages/*'
```

Similarly, `bun outdated` displays outdated dependencies for all packages in the monorepo, and `--filter` restricts the command to a subset of them:

```bash terminal icon="terminal"
# Display outdated dependencies for workspaces starting with `pkg-`
bun outdated --filter 'pkg-*'

# Display outdated dependencies for only the root package.json
bun outdated --filter './'
```

See [`bun install`](/pm/cli/install) and [`bun outdated`](/pm/cli/outdated).

---

## Running scripts with `--filter`

Use the `--filter` flag to execute scripts in multiple packages at once:

```bash terminal icon="terminal"
bun --filter <pattern> <script>
```

Say you have a monorepo with two packages: `packages/api` and `packages/frontend`, both with a `dev` script that starts a local development server. Normally, you would open two terminal tabs, `cd` into each package directory, and run `bun dev`:

```bash terminal icon="terminal"
cd packages/api
bun dev

# in another terminal
cd packages/frontend
bun dev
```

Using `--filter`, you can run the `dev` script in both packages at once:

```bash terminal icon="terminal"
bun --filter '*' dev
```

Both scripts run in parallel, and a terminal UI shows their respective outputs:

<Frame>![Terminal Output](https://github.com/oven-sh/bun/assets/48869301/2a103e42-9921-4c33-948f-a1ad6e6bac71)</Frame>

### Running scripts in workspaces

Filters respect your [workspace configuration](/pm/workspaces): if your `package.json` specifies which packages are part of the workspace,
`--filter` only matches those packages. In a workspace, `--filter` can also run scripts in packages located anywhere in the workspace:

```bash terminal icon="terminal"
# Packages
# src/foo
# src/bar

# in src/bar: runs myscript in src/foo, no need to cd!
bun run --filter foo myscript
```

### Parallel and sequential mode

Combine `--filter` or `--workspaces` with `--parallel` or `--sequential` to run scripts across workspace packages with Foreman-style prefixed output:

```bash terminal icon="terminal"
# Run "build" in all matching packages concurrently
bun run --parallel --filter '*' build

# Run "build" in all workspace packages sequentially
bun run --sequential --workspaces build

# Run glob-matched scripts across all packages
bun run --parallel --filter '*' "build:*"

# Continue running even if one package's script fails
bun run --parallel --no-exit-on-error --filter '*' test

# Run multiple scripts across all packages
bun run --parallel --filter '*' build lint
```

Each line of output is prefixed with the package and script name (`pkg-a:build | ...`). Without `--filter`/`--workspaces`, the prefix is just the script name (`build | ...`). When a package's `package.json` has no `name` field, Bun uses the relative path from the workspace root instead.

Use `--if-present` with `--workspaces` to skip packages that don't have the requested script instead of erroring.

### Dependency Order

Bun respects package dependency order when running scripts. Say you have a package `foo` that depends on another package `bar` in your workspace, and both have a `build` script. When you run `bun --filter '*' build`, `foo` only starts once `bar` is done.
