fetch with unix domain sockets in Bun

In Bun, the unix option in fetch() lets you send HTTP requests over a unix domain socket.

const unix = "/var/run/docker.sock";

const response = await fetch("http://localhost/info", { unix });

const body = await response.json();
console.log(body); // { ... }

The unix option is a string that specifies the local file path to a unix domain socket. The fetch() function will use the socket to send the request to the server instead of using a TCP network connection. https is also supported by using the https:// protocol in the URL instead of http://.

To send a POST request to an API endpoint over a unix domain socket:

const response = await fetch("https://hostname/a/path", {
  unix: "/var/run/path/to/unix.sock",
  method: "POST",
  body: JSON.stringify({ message: "Hello from Bun!" }),
  headers: {
    "Content-Type": "application/json",

const body = await response.json();