TypeScript: extend Window object

Suppose you’re using a JavaScript library that adds a tidioChatApi property to the Window object. You can tell TypeScript about this global property by adding something like the following to a d.ts file (e.g., types/window.d.ts).

declare global {
  interface Window {
    tidioChatApi: { [key: string]: any } // or whatever type
  }
}

export {}