# ASP.NET MVC Core Integration
This topic explains how to create an ASP.NET Core application using ActiveReports and render the reports in the JSViewer.
## Content
## Introduction
The JavaScript (JS) Report Viewer is an HTML/JS component that you can integrate into web applications of any architecture, including frameworks like React, Angular, Svelte, and others. This page details the integration steps.
## Configuring Middleware
The JS Report Viewer communicates with server-side middleware to request report rendering, monitor progress, retrieve rendered pages, and more. The first step in integrating the JS Report Viewer into your application is [Configuring Report Viewer Middleware](/activereportsnet/docs/v20.1/developers/create-applications/web-viewer-and-web-designer-middlewares/jsvieweraspnet-middleware){:target="_blank"}.
## Installing required NPM Packages
The JS Report Viewer is distributed via the [@mescius/activereportsnet-viewer](https://www.npmjs.com/package/@mescius/activereportsnet-viewer) npm package. Depending on your application type, you can install it directly using `npm` or `yarn`, use the `LibMan` tool, or download and copy the package contents into your project. Here is an example of installing the package using `npm`:
```bash
npm i @mescius/activereportsnet-viewer
```
## Including Report Viewer Styles
The JS Report Viewer requires CSS styles that need to be included in your application. You can find these CSS files in the dist folder of the `@mescius/activereportsnet-viewer` package:
* `jsViewer.min.css` - must always be included in your application\.
* `jsViewer.chart.min.css` - should be included if your reports contain charts\.
## Using Report Viewer Modules
The JS Report Viewer distribution includes both `AMD` and `ESM` modules. If you’re integrating the viewer into an application that uses `AMD` modules, include a script reference to the `jsViewer.min.js` file from the `dist` folder of the `@mescius/activereportsnet-viewer` package and invoke the `GrapeCity.ActiveReports.JSViewer.create` API. Pass in the CSS selector of the viewer host and the configuration options as shown below:
```html
@page
@{
Layout = null;
}
ActiveReports JS Report Viewer
```
Alternatively, you can use ESM modules and invoke the `createViewer` method provided by the `@mescius/activereportsnet-viewer` package, for example:
```html
ActiveReports JS Report Viewer
```