Nx Monorepo

Nx Monorepo

Overview

Provides guidance for Nx monorepo management in TypeScript/JavaScript projects. Covers workspace creation, project generation, task execution, caching strategies, Module Federation, and CI/CD integration.

When to Use

Use this skill when:

• Creating a new Nx workspace or initializing Nx in an existing project
• Generating applications, libraries, or components with Nx generators
• Running affected commands or executing tasks across multiple projects
• Setting up CI/CD pipelines for Nx projects (GitHub Actions, CircleCI, etc.)
• Configuring Module Federation with React or Next.js
• Implementing NestJS backend applications within Nx
• Managing TypeScript package libraries with buildable and publishable libs
• Setting up remote caching or Nx Cloud
• Optimizing monorepo build times and caching strategies
• Debugging dependency graph issues or circular dependencies

Trigger phrases: "create Nx workspace", "Nx monorepo", "generate Nx app", "Nx affected", "Nx CI/CD", "Module Federation Nx", "Nx Cloud"

Instructions

Workspace Creation

1. Create a new workspace with interactive setup:

   npx create-nx-workspace@latest

   Follow prompts to select preset (Integrated, Standalone, Package-based) and framework stack.

2. Initialize Nx in an existing project:

   nx@latest init

3. Create with specific preset (non-interactive):

   npx create-nx-workspace@latest my-workspace --preset=react

   Verify: nx show projects lists the new workspace projects

Project Generation

1. Generate a React application:

   nx g @nx/react:app my-app

2. Generate a library:

   # React library
   nx g @nx/react:lib my-lib
   
   # TypeScript library
   nx g @nx/js:lib my-util

   Verify: nx show projects lists the new lib

3. Generate a component in lib:

   nx g @nx/react:component my-comp --project=my-lib

4. Generate NestJS backend:

   nx g @nx/nest:app my-api

   Verify: nx show projects lists my-api and nx run my-api:build succeeds

Task Execution

1. Run tasks for affected projects only:

   nx affected -t lint test build

2. Run tasks across all projects:

   # Build all projects
   nx run-many -t build
   
   # Test specific projects
   nx run-many -t test -p=my-app,my-lib
   
   # Test by pattern
   nx run-many -t test --projects=*-app

3. Run specific target on single project:

   nx run my-app:build

4. Visualize dependency graph:

   nx graph

Project Configuration

Each project has a project.json defining targets, executor, and configurations:

{
  "name": "my-app",
  "projectType": "application",
  "sourceRoot": "apps/my-app/src",
  "targets": {
    "build": {
      "executor": "@nx/react:webpack",
      "outputs": ["{workspaceRoot}/dist/apps/my-app"],
      "configurations": {
        "production": {
          "optimization": true
        }
      }
    },
    "test": {
      "executor": "@nx/vite:test"
    }
  },
  "tags": ["type:app", "scope:frontend"]
}

Dependency Management

1. Set up project dependencies:

   {
     "targets": {
       "build": {
         "dependsOn": [
           { "projects": ["shared-ui"], "target": "build" }
         ]
       }
     }
   }

2. Use tags for organization:

   { "tags": ["type:ui", "scope:frontend", "platform:web"] }

Module Federation (Nx 17+)

1. Generate a remote (micro-frontend):

   nx g @nx/react:remote checkout --host=dashboard

2. Generate a host:

   nx g @nx/react:host dashboard

CI/CD Setup

Use affected commands in CI to only build/test changed projects:

# .github/workflows/ci.yml
- run: npx nx affected -t lint --parallel
- run: npx nx affected -t test --parallel
- run: npx nx affected -t build --parallel

Examples

Example 1: Create New React Workspace

Input: "Create a new Nx workspace with React and TypeScript"

Steps:

npx create-nx-workspace@latest my-workspace
# Select: Integrated Monorepo → React → Integrated monorepo (Nx Cloud)

Verify: cd my-workspace && nx show projects lists the created app

Expected Result: Workspace created with:

• apps/ directory with React app
• libs/ directory for shared libraries
• nx.json with cache configuration
• CI/CD workflow files ready

Example 2: Run Tests for Changed Projects

Input: "Run tests only for projects affected by recent changes"

Command:

nx affected -t test --base=main~1 --head=main

Expected Result: Only tests for projects affected by changes between commits are executed, leveraging cached results from previous runs.

Example 3: Generate and Build a Shared Library

Input: "Create a shared UI library and use it in the app"

Steps:

# Generate library
nx g @nx/react:lib shared-ui

# Generate component in library
nx g @nx/react:component button --project=shared-ui

# Import in app (tsconfig paths auto-configured)
import { Button } from '@my-workspace/shared-ui'

Verify: nx run shared-ui:build completes successfully and nx graph shows the dependency link to your app

Expected Result: Buildable library at libs/shared-ui with proper TypeScript path mapping configured.