angular-cli/docs/documentation/stories/multiple-apps.md

Multiple Apps integration

Angular CLI support multiple applications within one project. You use the apps array in .angular-cli.json to list files and folders you want to use for different apps.

By default one app is created when then new project is created and apps array looks like:

"apps": [
  {
    "root": "src",
    ...
    "main": "main.ts",
    "polyfills": "polyfills.ts",
    "test": "test.ts",
    "tsconfig": "tsconfig.app.json",
    "testTsconfig": "tsconfig.spec.json",
    "prefix": "app",
    ...
  }
],

To create another app you can copy the app object and then change the values for the options you want to change. eg. If I want to create another app with different main, polyfills, test and prefix and keep other configurations such as assets, styles, environment etc. same. I can add it to apps array as below.

"apps": [
  {
    "root": "src",
    ...
    "main": "main.ts",
    "polyfills": "polyfills.ts",
    "test": "test.ts",
    "tsconfig": "tsconfig.app.json",
    "testTsconfig": "tsconfig.spec.json",
    "prefix": "app",
    ...
  },
  {
    "root": "src",
    ...
    "main": "main2.ts",
    "polyfills": "polyfills2.ts",
    "test": "test2.ts",
    "tsconfig": "tsconfig.app.json",
    "testTsconfig": "tsconfig.spec.json",
    "prefix": "app2",
    ...
  }  
],

Now we can serve, build etc. both the apps by passing the app index with the commands. By default, it will pick the first app only.

To serve the first app: ng serve --app=0 or ng serve --app 0

To serve the second app: ng serve --app=1 or ng serve --app 1

You can also add the name property to the app object in apps array and then pass it to commands to distinguish between different applications.

"apps": [
  {
    "name": "app1",
    "root": "src",
    "outDir": "dist",
....

To serve application by name ng serve --app=app1 or ng serve --app app1.