agent-base — Custom HTTP Agent Helper

Helps users create custom http.Agent subclasses based on the agent-base module, for scenarios such as HTTP request proxying, custom socket connections, etc.

Trigger Scenarios

Use when the user needs to write HTTP/HTTPS/SOCKS/PAC proxies, custom HTTP connection logic, or extend http.Agent.

Module Overview

agent-base wraps an ordinary function into an http.Agent instance. It is an abstract class that requires defining the connect(req, opts) method to create the underlying Socket.

• connect() can return any Duplex stream, or another http.Agent instance to delegate the request
• connect() can be an async function
• opts.secureEndpoint is used to distinguish between HTTP / HTTPS

Quick Start

import * as net from 'net';
import * as tls from 'tls';
import * as http from 'http';
import { Agent } from 'agent-base';

class MyAgent extends Agent {
  connect(req, opts) {
    if (opts.secureEndpoint) {
      return tls.connect(opts);
    } else {
      return net.connect(opts);
    }
  }
}

const agent = new MyAgent({ keepAlive: true });
http.get('http://nodejs.org/api/', { agent }, (res) => {
  console.log('"response" event!', res.headers);
  res.pipe(process.stdout);
});

Workflow

1. Identify user requirements: Pure HTTP/HTTPS proxy? SOCKS? PAC? Or custom routing?
2. If a mature solution exists, prioritize recommending community subclasses (see below)
3. If custom implementation is needed, write the connect() method based on the Agent abstract class
4. Provide complete, runnable TypeScript/JavaScript examples

Proxy Details

See references/proxy-details.md, which includes:

• http-proxy-agent — HTTP endpoint proxy
• https-proxy-agent — HTTPS endpoint proxy
• pac-proxy-agent — PAC file proxy
• socks-proxy-agent — SOCKS proxy
• Selection guide and comparison of each subclass