npm-packages.md
# Workspace npm dependencies
The Angular Framework, Angular CLI, and components used by Angular applications are packaged as [npm packages](https://docs.npmjs.com/getting-started/what-is-npm "What is npm?") and distributed using the [npm registry](https://docs.npmjs.com).
You can download and install these npm packages by using the [npm CLI client](https://docs.npmjs.com/cli/install), which is installed with and runs as a [Node.js®](https://nodejs.org "Nodejs.org") application.
By default, the Angular CLI uses the npm client.
Alternatively, you can use the [yarn client](https://yarnpkg.com) for downloading and installing npm packages.
<div class="alert is-helpful">
See [Local Environment Setup](guide/setup-local "Setting up for Local Development") for information about the required versions and installation of `Node.js` and `npm`.
If you already have projects running on your machine that use other versions of Node.js and npm, consider using [nvm](https://github.com/creationix/nvm) to manage the multiple versions of Node.js and npm.
</div>
## `package.json`
Both `npm` and `yarn` install the packages that are identified in a [`package.json`](https://docs.npmjs.com/files/package.json) file.
The CLI command `ng new` creates a `package.json` file when it creates the new workspace.
This `package.json` is used by all projects in the workspace, including the initial application project that is created by the CLI when it creates the workspace.
Initially, this `package.json` includes *a starter set of packages*, some of which are required by Angular and others that support common application scenarios.
You add packages to `package.json` as your application evolves.
You may even remove some.
The `package.json` is organized into two groups of packages:
| Packages | Details |
|:--- |:--- |
| [Dependencies](guide/npm-packages#dependencies) | Essential to *running* applications. |
| [DevDependencies](guide/npm-packages#dev-dependencies) | Only necessary to *develop* and *build* applications. |
<div class="alert is-helpful">
**LIBRARY DEVELOPERS**: <br />
By default, the CLI command [`ng generate library`](cli/generate) creates a `package.json` for the new library.
That `package.json` is used when publishing the library to npm.
For more information, see the CLI wiki page [Library Support](guide/creating-libraries).
</div>
<a id="dependencies"></a>
## Dependencies
The packages listed in the `dependencies` section of `package.json` are essential to *running* applications.
The `dependencies` section of `package.json` contains:
| Packages | Details |
|:--- |:--- |
| [Angular packages](#angular-packages) | Angular core and optional modules; their package names begin `@angular` |
| [Support packages](#support-packages) | 3rd party libraries that must be present for Angular applications to run |
| [Polyfill packages](#polyfills) | Polyfills plug gaps in a browser's JavaScript implementation |
To add a new dependency, use the [`ng add`](cli/add) command.
<a id="angular-packages"></a>
### Angular packages
The following Angular packages are included as dependencies in the default `package.json` file for a new Angular workspace.
For a complete list of Angular packages, see the [API reference](api?type=package).
| Package name | Details |
|:--- |:--- |
| [`@angular/animations`](api/animations) | Angular's animations library makes it easy to define and apply animation effects such as page and list transitions. For more information, see the [Animations guide](guide/animations). |
| [`@angular/common`](api/common) | The commonly-needed services, pipes, and directives provided by the Angular team. The [`HttpClientModule`](api/common/http/HttpClientModule) is also here, in the [`@angular/common/http`](api/common/http) subfolder. For more information, see the [HttpClient guide](guide/understanding-communicating-with-http). |
| `@angular/compiler` | Angular's template compiler. It understands templates and can convert them to code that makes the application run and render. Typically you don't interact with the compiler directly; rather, you use it indirectly using `platform-browser-dynamic` when JIT compiling in the browser. For more information, see the [Ahead-of-time Compilation guide](guide/aot-compiler). |
| [`@angular/core`](api/core) | Critical runtime parts of the framework that are needed by every application. Includes all metadata decorators, `Component`, `Directive`, dependency injection, and the component lifecycle hooks. |
| [`@angular/forms`](api/forms) | Support for both [template-driven](guide/forms) and [reactive forms](guide/reactive-forms). For information about choosing the best forms approach for your app, see [Introduction to forms](guide/forms-overview). |
| [`@angular/platform-browser`](api/platform-browser) | Everything DOM and browser related, especially the pieces that help render into the DOM. This package also includes the `bootstrapModuleFactory()` method for bootstrapping applications for production builds that pre-compile with [AOT](guide/aot-compiler). |
| [`@angular/platform-browser-dynamic`](api/platform-browser-dynamic) | Includes [providers](api/core/Provider) and methods to compile and run the application on the client using the [JIT compiler](guide/aot-compiler). |
| [`@angular/router`](api/router) | The router module navigates among your application pages when the browser URL changes. For more information, see [Routing and Navigation](guide/router). |
<a id="support-packages"></a>
### Support packages
The following support packages are included as dependencies in the default `package.json` file for a new Angular workspace.
| Package name | Details |
|:--- |:--- |
| [`rxjs`](https://github.com/ReactiveX/rxjs) | Many Angular APIs return [*observables*](guide/glossary#observable). RxJS is an implementation of the proposed [Observables specification](https://github.com/tc39/proposal-observable) currently before the [TC39](https://www.ecma-international.org/memento/tc39.htm) committee, which determines standards for the JavaScript language. |
| [`zone.js`](https://github.com/angular/zone.js) | Angular relies on zone.js to run Angular's change detection processes when native JavaScript operations raise events. Zone.js is an implementation of a [specification](https://gist.github.com/mhevery/63fdcdf7c65886051d55) currently before the [TC39](https://www.ecma-international.org/memento/tc39.htm) committee that determines standards for the JavaScript language. |
<a id="polyfills"></a>
### Polyfill packages
Many browsers lack native support for some features in the latest HTML standards, features that Angular requires.
[*Polyfills*](https://en.wikipedia.org/wiki/Polyfill_(programming)) can emulate the missing features.
The [Browser Support](guide/browser-support) guide explains which browsers need polyfills and how you can add them.
<a id="dev-dependencies"></a>
## DevDependencies
The packages listed in the `devDependencies` section of `package.json` help you develop the application on your local machine.
You don't deploy them with the production application.
To add a new `devDependency`, use either one of the following commands:
<code-example format="shell" language="shell">
npm install --save-dev <package-name>
</code-example>
<code-example format="shell" language="shell">
yarn add --dev <package-name>
</code-example>
The following `devDependencies` are provided in the default `package.json` file for a new Angular workspace.
| Package name | Details |
|:--- |:--- |
| [`@angular-devkit/build-angular`](https://github.com/angular/angular-cli) | The Angular build tools. |
| [`@angular/cli`](https://github.com/angular/angular-cli) | The Angular CLI tools. |
| `@angular/compiler-cli` | The Angular compiler, which is invoked by the Angular CLI's `ng build` and `ng serve` commands. |
| `@types/... ` | TypeScript definition files for 3rd party libraries such as Jasmine and Node.js. |
| `jasmine/... ` | Packages to support the [Jasmine](https://jasmine.github.io) test library. |
| `karma/... ` | Packages to support the [karma](https://www.npmjs.com/package/karma) test runner. |
| [`typescript`](https://www.npmjs.com/package/typescript) | The TypeScript language server, including the *tsc* TypeScript compiler. |
## Related information
For information about how the Angular CLI handles packages see the following guides:
| Topics | Details |
|:--- |:--- |
| [Building and serving](guide/build) | How packages come together to create a development build |
| [Deployment](guide/deployment) | How packages come together to create a production build |
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@reviewed 2022-02-28
