Link Workspace Packages

Add dependencies between packages in a monorepo. All package managers support workspaces but with different syntax.

Detect Package Manager

Check whether there's a packageManager field in the root-level package.json.

Alternatively check lockfile in repo root:

• pnpm-lock.yaml → pnpm
• yarn.lock → yarn
• bun.lock / bun.lockb → bun
• package-lock.json → npm

Workflow

1. Identify consumer package (the one importing)
2. Identify provider package(s) (being imported)
3. Add dependency using package manager's workspace syntax
4. Verify symlinks created in consumer's node_modules/

pnpm

Uses workspace: protocol - symlinks only created when explicitly declared.

# From consumer directory
pnpm add @org/ui --workspace

# Or with --filter from anywhere
pnpm add @org/ui --filter @org/app --workspace

Result in package.json:

{ "dependencies": { "@org/ui": "workspace:*" } }

yarn (v2+/berry)

Also uses workspace: protocol.

yarn workspace @org/app add @org/ui

Result in package.json:

{ "dependencies": { "@org/ui": "workspace:^" } }

npm

No workspace: protocol. npm auto-symlinks workspace packages.

npm install @org/ui --workspace @org/app

Result in package.json:

{ "dependencies": { "@org/ui": "*" } }

npm resolves to local workspace automatically during install.

bun

Supports workspace: protocol (pnpm-compatible).

cd packages/app && bun add @org/ui

Result in package.json:

{ "dependencies": { "@org/ui": "workspace:*" } }

Examples

Example 1: pnpm - link ui lib to app

pnpm add @org/ui --filter @org/app --workspace

Example 2: npm - link multiple packages

npm install @org/data-access @org/ui --workspace @org/dashboard

Example 3: Debug "Cannot find module"

1. Check if dependency is declared in consumer's package.json
2. If not, add it using appropriate command above
3. Run install (pnpm install, npm install, etc.)

Notes

• Symlinks appear in <consumer>/node_modules/@org/<package>
• Hoisting differs by manager:

- npm/bun: hoist shared deps to root nodemodules - pnpm: no hoisting (strict isolation, prevents phantom deps) - yarn berry: uses Plug'n'Play by default (no nodemodules)

• Root package.json should have "private": true to prevent accidental publish