Built-in TypeScript support

Deno natively understands TypeScript code with no compiler to configure. Start writing code in .ts files, and the runtime will work with them just fine.

Define an interface in TypeScript

interface Person {
  name: string;
  age: number;
}

Provide a typed input to a function

function greet(person: Person) {
  return "Hello, " + person.name + "!";
}

Everything works with zero config!

console.log(greet({ name: "Alice", age: 36 }));

Run this example locally using the Deno CLI:

deno run https://docs.deno.com/by-example/typescript.ts

Additional resources:

TypeScript handbook