⚡ VERSION 2.1.0 IS OUT

RunTime-Now

A small, fast JavaScript & TypeScript runtime written in C++. One ~3 MB binary, TypeScript out of the box, and a Web-standard HTTP server.

$curl -fsSL https://byteforgestudiolab.github.io/RunTime-Now/install | bash Copy

Linux x64 & arm64 · then run rtn --help · upgrade anytime with rtn upgrade

🟦

TypeScript, natively

Run .ts files directly. Types are stripped in C++ with line numbers preserved, so stack traces point at your source.

🌐

Web-standard server

rtn.serve() with Request, Response, Headers and URL: the same shape as Deno and Bun.

🪶

Tiny footprint

A static ~3 MB binary with no dependencies, ~10 ms startup and an HTTP server in ~3 MB of RAM.

🔄

One-command upgrades

rtn upgrade downloads the latest release, verifies its SHA-256 and swaps it in atomically.

Hello, server

// server.ts — run it with: rtn server.ts
interface Todo { id: number; title: string }
const todos: Todo[] = [];

rtn.serve({ port: 3000 }, async (req: Request) => {
  if (req.method === "POST") {
    todos.push({ id: todos.length + 1, ...(await req.json()) });
    return Response.json(todos.at(-1), { status: 201 });
  }
  return Response.json(todos);
});

Small and quick

Runtime	Requests/s	Memory	Startup
⚡ rtn 1.5	51,751	3.2 MB	10 ms
Node 24	55,466	89.0 MB	44 ms
Bun 1.4	99,590	38.8 MB	2 ms
Deno 2.9	113,984	43.6 MB	29 ms

"Hello World" HTTP server, HTTP/1.1 keep-alive, 64 connections, same machine. rtn uses the QuickJS-ng interpreter; Bun and Deno use JIT engines.