bun-http-server

Bun HTTP Server

Bun has a built-in high-performance HTTP server via Bun.serve().

Quick Start

const server = Bun.serve({
  port: 3000,
  fetch(req) {
    return new Response("Hello World!");
  },
});

console.log(`Server running at http://localhost:${server.port}`);

Request Handling

Bun.serve({
  fetch(req) {
    const url = new URL(req.url);

    // Method
    console.log(req.method); // GET, POST, etc.

    // Path
    console.log(url.pathname); // /api/users

    // Query params
    console.log(url.searchParams.get("id")); // ?id=123

    // Headers
    console.log(req.headers.get("Content-Type"));

    return new Response("OK");
  },
});

Body Parsing

Bun.serve({
  async fetch(req) {
    // JSON
    const json = await req.json();

    // Form data
    const form = await req.formData();

    // Text
    const text = await req.text();

    // ArrayBuffer
    const buffer = await req.arrayBuffer();

    // Blob
    const blob = await req.blob();

    return new Response("Received");
  },
});

Response Types

Bun.serve({
  fetch(req) {
    const url = new URL(req.url);

    switch (url.pathname) {
      case "/json":
        return Response.json({ message: "Hello" });

      case "/html":
        return new Response("<h1>Hello</h1>", {
          headers: { "Content-Type": "text/html" },
        });

      case "/redirect":
        return Response.redirect("/new-location", 302);

      case "/file":
        return new Response(Bun.file("./image.png"));

      case "/stream":
        return new Response(
          new ReadableStream({
            start(controller) {
              controller.enqueue("chunk1");
              controller.enqueue("chunk2");
              controller.close();
            },
          })
        );

      default:
        return new Response("Not Found", { status: 404 });
    }
  },
});

Simple Routing

Bun.serve({
  fetch(req) {
    const url = new URL(req.url);
    const path = url.pathname;
    const method = req.method;

    // Static routes
    if (method === "GET" && path === "/") {
      return new Response("Home");
    }

    if (method === "GET" && path === "/api/users") {
      return Response.json([{ id: 1, name: "Alice" }]);
    }

    // Dynamic routes
    const userMatch = path.match(/^\/api\/users\/(\d+)$/);
    if (method === "GET" && userMatch) {
      const userId = userMatch[1];
      return Response.json({ id: userId });
    }

    // 404
    return new Response("Not Found", { status: 404 });
  },
});