These docs are for an old release. Info on upgrading to v6
edit doc

TypeScript Support

It is possible to use FullCalendar and Scheduler with TypeScript, a type-aware superset of the JavaScript language that compiles down to JavaScript. TypeScript is great for the maintainability of large JavaScript projects, however, it is probably overkill for smaller projects. Learn more about TypeScript »

You will then need to set up some sort of build system that compiles TypeScript to JavaScript. You can use the tsc compiler directly or you can use a more sophisticated system like Webpack.

Once you have your build system set up, you can begin to write type-aware code like this:

example.ts:

import { Calendar } from '@fullcalendar/core';
import dayGridPlugin from '@fullcalendar/daygrid';

document.addEventListener('DOMContentLoaded', function() {
  let calendarEl: HTMLElement = document.getElementById('calendar')!;

  let calendar = new Calendar(calendarEl, {
    plugins: [ dayGridPlugin ]
    // options here
  });

  calendar.render();
});