Run TypeScript Directly in Node.js with the New Experimental Flag

Node.js v22.6.0 introduces the experimental flag --experimental-strip-types, which enables direct execution of TypeScript files by stripping type annotations at runtime without performing type checking.

Usage

Upgrade Node.js to v22.6.0.

Create a TypeScript entry file, e.g., app.ts.

Run the file with the experimental flag:

node --experimental-strip-types app.ts

Type‑only Import Requirement

Because the runtime strips types, imports that bring in only types must be prefixed with the type keyword. Omitting type causes Node.js to treat the import as a value import, leading to a runtime error.

Example

// user.ts
export type User = {
  name: string;
};
export function getUser(id: string) {
  const user: User = { name: 'hhh' };
  return user;
}

// app.ts
import type { User } from "./user.ts";
import { getUser } from "./user.ts";

const user: User = getUser('1');
console.log(user);

Current Limitations

Only inline type annotations are stripped; enums, namespaces, and similar constructs are not supported.

All type‑only imports must use the type keyword.

The tsconfig.json file is ignored.

Import statements must include the file extension (e.g., ./user.ts).

TypeScript handling is disabled by default inside node_modules.

References

https://nodejs.org/docs/latest/api/typescript.html

https://nodejs.org/en/blog/release/v22.6.0