Workspaces

Workspaces allow you to manage multiple packages within a single repository (monorepo).

Configuration

Define workspaces in the root package.json:

{
  "workspaces": ["packages/*"]
}

This tells Bun that every directory in packages/ is a workspace.

Glob patterns

Use glob patterns to match workspace directories:

{
  "workspaces": [
    "packages/*",
    "apps/*",
    "tools/*"
  ]
}

Negative patterns

Exclude specific directories:

{
  "workspaces": [
    "packages/*",
    "!packages/ignored"
  ]
}

Structure

Typical monorepo structure:

my-monorepo/
├── package.json          # Root package.json with workspaces
├── bun.lockb             # Shared lockfile
├── node_modules/         # Shared dependencies
├── packages/
│   ├── app/
│   │   ├── package.json
│   │   └── src/
│   ├── shared/
│   │   ├── package.json
│   │   └── src/
│   └── utils/
│       ├── package.json
│       └── src/
└── apps/
    └── web/
        ├── package.json
        └── src/

Installing

Install all workspaces

From the root:

bun install

Installs dependencies for all workspace packages and links inter-workspace dependencies.

Install in specific workspace

cd packages/app
bun install

Or from root:

bun install --cwd packages/app

Inter-workspace dependencies

Reference by name

Workspace packages can depend on each other:

// packages/app/package.json
{
  "name": "@myorg/app",
  "dependencies": {
    "@myorg/shared": "workspace:*"
  }
}

The workspace: protocol tells Bun to link to the local workspace package.

Version protocols

{
  "dependencies": {
    "@myorg/shared": "workspace:*",      // Any version
    "@myorg/utils": "workspace:^1.0.0",  // Semver range
    "@myorg/types": "workspace:~",       // Current version
  }
}

Automatic linking

When you run bun install, workspace dependencies are automatically linked:

$ bun install
bun install v1.0.0

+ @myorg/shared (workspace)
+ @myorg/utils (workspace)

134 packages installed [1.83s]

Adding dependencies

Add to specific workspace

From workspace directory:

cd packages/app
bun add react

From root:

bun add react --cwd packages/app

Add workspace dependency

cd packages/app
bun add @myorg/shared@workspace:*

Or edit package.json manually:

{
  "dependencies": {
    "@myorg/shared": "workspace:*"
  }
}

Then run bun install.

Add to root workspace

Add shared development dependencies to root:

# From root
bun add -D typescript @types/node

Root package.json:

{
  "workspaces": ["packages/*"],
  "devDependencies": {
    "typescript": "^5.0.0",
    "@types/node": "^20.0.0"
  }
}

Running scripts

Run in specific workspace

cd packages/app
bun run build

Or from root:

bun --cwd packages/app run build

Run in all workspaces

Run a script across all workspaces:

# Using a script runner like Turborepo
turbo run build

# Or manually
for dir in packages/*; do
  (cd "$dir" && bun run build)
done

Filtering workspaces

Run commands in specific workspaces:

# Install only for specific workspace
bun install --filter "@myorg/app"

# Update packages in specific workspace
bun update --filter "@myorg/app"

# Check outdated in specific workspace
bun outdated --filter "@myorg/app"

With patterns:

# All packages with @myorg scope
bun install --filter "@myorg/*"

# Multiple filters
bun install --filter "@myorg/app" --filter "@myorg/shared"

Workspace resolution

Bun resolves workspace dependencies in this order:

Exact workspace match
Version range match within workspaces
External registry

Resolution examples

Given workspaces:

@myorg/utils version 1.0.0
@myorg/helpers version 2.0.0

{
  "dependencies": {
    "@myorg/utils": "workspace:*",      // → @myorg/[email protected] (workspace)
    "@myorg/utils": "workspace:^1.0.0", // → @myorg/[email protected] (workspace)
    "@myorg/utils": "workspace:^2.0.0", // → @myorg/utils@latest (registry)
    "@myorg/utils": "*"                 // → @myorg/[email protected] (workspace)
  }
}

Publishing workspaces

Publish individual workspace

cd packages/utils
bun publish

Workspace protocol in published packages

When publishing, workspace: dependencies are converted: Before publishing:

{
  "dependencies": {
    "@myorg/shared": "workspace:^1.0.0"
  }
}

Published version:

{
  "dependencies": {
    "@myorg/shared": "^1.0.0"
  }
}

Pre-publish validation

Ensure workspace dependencies exist in registry before publishing:

# Publish shared packages first
cd packages/shared && bun publish

# Then publish packages that depend on them
cd ../app && bun publish

Common patterns

Shared TypeScript config

Root tsconfig.json:

{
  "compilerOptions": {
    "target": "ES2020",
    "module": "ESNext",
    "strict": true
  }
}

Workspace tsconfig.json:

{
  "extends": "../../tsconfig.json",
  "compilerOptions": {
    "outDir": "./dist",
    "rootDir": "./src"
  }
}

Shared development tools

Install shared tools at root:

{
  "devDependencies": {
    "typescript": "^5.0.0",
    "@biomejs/biome": "^1.0.0",
    "vitest": "^1.0.0"
  },
  "scripts": {
    "test": "vitest",
    "lint": "biome check .",
    "format": "biome format --write ."
  }
}

Private packages

Mark workspace packages as private if not publishing:

{
  "name": "@myorg/app",
  "private": true
}

Benefits

Share code between packages without publishing:

// packages/shared/src/utils.ts
export function formatDate(date: Date) {
  return date.toISOString();
}

// packages/app/src/index.ts
import { formatDate } from "@myorg/shared";

Dependency deduplication

Shared dependencies are hoisted to root node_modules:

node_modules/
├── react/           # Shared by multiple workspaces
├── react-dom/       # Shared by multiple workspaces
└── typescript/      # Shared dev dependency

Atomic changes

Make changes across multiple packages in a single commit:

# Update API in shared package
cd packages/shared
# Update code

# Update consumers
cd ../app
# Update code to match new API

# Commit everything together
git add .
git commit -m "Update API"

Troubleshooting

Workspace not found

If Bun can’t find a workspace:

Check workspace glob patterns in root package.json
Ensure workspace has a package.json with name field
Run bun install from root

Dependencies not linking

If workspace dependencies aren’t linking:

# Clear cache and reinstall
rm -rf node_modules bun.lockb
bun install

Version mismatches

Ensure workspace versions match dependency ranges:

// packages/shared/package.json
{
  "version": "1.0.0"
}

// packages/app/package.json
{
  "dependencies": {
    "@myorg/shared": "workspace:^1.0.0"  // Matches!
  }
}

Migration from other package managers

From npm/Yarn workspaces

Bun workspaces are compatible:

// Works with Bun
{
  "workspaces": ["packages/*"]
}

Replace workspace: protocols:

// Before (Yarn)
{"dependencies": {"pkg": "workspace:*"}}

// After (Bun, same!)
{"dependencies": {"pkg": "workspace:*"}}

From pnpm

Convert pnpm-workspace.yaml:

# pnpm-workspace.yaml
packages:
  - 'packages/*'

To package.json:

{
  "workspaces": ["packages/*"]
}

Examples

Full stack monorepo

{
  "name": "my-app",
  "workspaces": [
    "packages/*",
    "apps/*"
  ],
  "devDependencies": {
    "typescript": "^5.0.0"
  }
}

Structure:

├── apps/
│   ├── web/           # React frontend
│   └── api/           # Backend API
├── packages/
│   ├── ui/            # Shared UI components
│   ├── utils/         # Shared utilities
│   └── types/         # Shared TypeScript types
└── package.json

Library monorepo

{
  "name": "@mylib/monorepo",
  "workspaces": ["packages/*"],
  "private": true
}

Structure:

├── packages/
│   ├── core/          # @mylib/core
│   ├── react/         # @mylib/react
│   ├── vue/           # @mylib/vue
│   └── utils/         # @mylib/utils
└── package.json

Commands

Configuration

​Configuration

​Glob patterns

​Negative patterns

​Structure

​Installing

​Install all workspaces

​Install in specific workspace

​Inter-workspace dependencies

​Reference by name

​Version protocols

​Automatic linking

​Adding dependencies

​Add to specific workspace

​Add workspace dependency

​Add to root workspace

​Running scripts

​Run in specific workspace

​Run in all workspaces

​Filtering workspaces

​Workspace resolution

​Resolution examples

​Publishing workspaces

​Publish individual workspace

​Workspace protocol in published packages

​Pre-publish validation

​Common patterns

​Shared TypeScript config

​Shared development tools

​Private packages

​Benefits

​Code sharing

​Dependency deduplication

​Atomic changes

​Troubleshooting

​Workspace not found

​Dependencies not linking

​Version mismatches

​Migration from other package managers

​From npm/Yarn workspaces

​From pnpm

​Examples

​Full stack monorepo

​Library monorepo

Build docs developers (and LLMs) love

Configuration

Glob patterns

Negative patterns

Structure

Installing

Install all workspaces

Install in specific workspace

Inter-workspace dependencies

Reference by name

Version protocols

Automatic linking

Adding dependencies

Add to specific workspace

Add workspace dependency

Add to root workspace

Running scripts

Run in specific workspace

Run in all workspaces

Filtering workspaces

Workspace resolution

Resolution examples

Publishing workspaces

Publish individual workspace

Workspace protocol in published packages

Pre-publish validation

Common patterns

Shared TypeScript config

Shared development tools

Private packages

Benefits

Code sharing

Dependency deduplication

Atomic changes

Troubleshooting

Workspace not found

Dependencies not linking

Version mismatches

Migration from other package managers

From npm/Yarn workspaces

From pnpm

Examples

Full stack monorepo

Library monorepo