Using Plugins

SystemJS plugins are installed like any other dependency in jspm, and can be found listed at the top of the jspm registry.

Plugins are installed by name:

  jspm install css

To use a plugin, add a ! to the end of a require:

import './some/style.css!';

The plugin name is taken from the extension name. You can also add any plugin name after the ! to load with a different plugin than the extension name:

  jspm install json
import config from './config-service!json';

Plugins can also be used in dynamic imports - System.import('component.jsx!');

Plugins should always be declared as dependencies of the package they are used in - they are contextual modules just like any other dependency.


CSS is supported in jspm through the css plugin:

  jspm install css

CSS can then be declared as a dependency in the tree:

import './component.css!';

CSS should always be a dependency in your package.json if sharing a package that has CSS plugin requires of this form.

CSS Builds

The CSS plugin will inline and combine CSS requires into the bundle output when using jspm bundle. The following options can be added to the jspm config.js file to alter this behaviour further:

  • buildCSS: false add this option to opt-out of CSS inlining, and instead have the CSS loaded as separate files in production.
  • separateCSS: true add this option to create a bundle.js AND a bundle.css file which can be included with a separate link tag.

If using CSS imports, it is advisable to follow modular CSS best practises.

Read more at the CSS plugin project page -

Compiler Plugins

Compiler plugins are plugins like jsx (as well as json and text) allow you to load other languages into JavaScript. These provide implementations of the translate hook, which makes them buildable.

That is, when using jspm bundle compilations will be inline automatically, and the plugin itself will not be used in production. When in development, the plugin can optionally support in-browser compilation.

Separate file production of compiler plugins using pre-compilation is not currently supported, although this is a feature that is planned for implementation in future. For now only use compiler plugins if you're using jspm bundling.

Resource Plugins

These are plugins that are used to load production resources. For example, using the CSS plugin with builds disabled or the image plugin. The plugin does not build at all, and runs in production.