Proxy Auto Configuration (PAC) file generator & maintenance tool.

Features:

• Generate PAC files from various hostname sources.
• Load a PAC file and use it to proxy requests.
• Serve the PAC with http and watch for source change.
• Show what hosts in your browser history will be proxied by the PAC.

The pre-generated PAC file proxy.pac can be used to bypass GFW.

By default, it dispatches requests of blocked hosts to SOCKS5 localhost:2080, you can change the value to your proxy server address.

pac-maker requires NodeJS >= 16.

npm install pac-maker

pac-maker loads config file from working directory, default is pac.config.js, it can be specified by --config=<path> .

config file should export a configuration object:

import { builtinList, gfwlist, ofArray } from "pac-maker";

export default {
	path: "dist/proxy.pac",
	direct: "DIRECT",
	sources: {
		"SOCKS5 localhost:2080": [
			gfwlist(),
			builtinList("default"),
			builtinList("forbidden"),
			ofArray(["google.com"]),
		],
	},
};

There are some built-in sources in pac-maker:

• gfwlist Fetch hostnames from gfwlist.

• hostnameFile Read hostnames from a file, for hostname file example, see the list directory.

• builtinList Read hostnames from a file in the list directory.

• ofArray Just use an array of hostnames

Generate a PAC file:

node bin/pac-maker.js generate [--config=<path>] [--watch]

• --watch After the initial build, pac-maker will continue to watch for updates in any of the sources.

Find what hosts will be proxied by the PAC in browser history, support Chrome, Firefox, and Edge:

node bin/pac-maker.js analyze [--config=<path>] [--json=<path>]

• --json Save matched rules to this file, default is matches.json.

Serve the PAC file with http, and update when source have changes:

node bin/pac-maker.js serve [--config=<file>] [--host=<host>] [--port=<port>]

• --host By default, the server will accept connections from all addresses, It is possible to listen to just one selected interface using the host parameter.

• --port The port number that http server to listened on, default is 7568.

pac-maker exports some useful functions that allows you to play with PAC inside your own JavaScript program.

This package is pure ESM, It cannot be require()'d from CommonJS.

The undici dispatcher that dispatch requests based on rule described by the PAC.

It is designed to be used with the built-in fetch function. To proxy the requests with the http module, we recommend to use node-pac-proxy-agent.

import { readFileSync } from "fs";
import { PACDispatcher } from "pac-maker";

// Only needed if your Node < 18.1.0
// import { fetch } from "undici";

const pac = readFileSync("proxy.pac", "utf8");
const dispatcher = new PACDispatcher(pac);

const response = await fetch("https://example.com", { dispatcher });

Create a PAC script from rules, use the built-in template template/default.js.

The function takes two parameters, first is a rules object which key is a proxy string , and value is a hostname array. the second parameter will be returned from FindProxyForURL if no hostname matched, default is DIRECT.

import { writeFileSync } from "fs";
import { buildPAC } from "pac-maker";

const rules = {
	"HTTP 192.168.0.1:80": ["foo.com", "bar.com"],
	"SOCKS5 localhost:1080": ["example.com"],
};

writeFileSync("proxy.pac", buildPAC(rules));

Load and execute a PAC script, return an object includes all global variables defined in the PAC.

import { readFileSync } from "fs";
import { loadPAC } from "pac-maker";

const pac = loadPAC(readFileSync("proxy.pac", "utf8"));

console.log(pac.FindProxyForURL("", "example.com"));

Parse the return value of FindProxyForURL().

import { parseProxies } from "pac-maker";

console.log(parseProxies("HTTP localhost:80; DIRECT"));

output:

[
  { protocol: "HTTP", host: "localhost:80", port: 80, hostname: "localhost" },
  { protocol: "DIRECT", host: "", port: NaN, hostname: "" }
]

All commands supported by pac-maker can also be called in JavaScript code.

import { commands } from "pac-maker";
import config from "./pac.config.js";

commands.serve({ host: "localhost", port: 12345 }, config);

To run unit tests, you need to enable experimental vm modules.

NODE_OPTIONS=--experimental-vm-modules
pnpm test