OPEN SOURCE

See what moves
through your proxy.

A TypeScript proxy framework for intercepting and processing HTTP/1.1, HTTPS, WebSocket, and secure WebSocket traffic.

Get started →View on GitHub ↗

HTTP/1.1HTTPSWebSocketSecure WebSocket

A proxy core you can build on

mitm-core gives Node.js applications a foundation for observing and customizing proxied traffic, with configurable processing, rules, and plugins.

Observe the lifecycle

Subscribe to connection, request, WebSocket, and error events as traffic moves through the proxy.

Explore proxy events →

Extend with plugins

Add behavior through plugin lifecycle hooks and work with the request scope.

Read the plugin guide →

Control traffic with rules

Define matching rules and manage rule stores for decisions such as TLS bypass.

Learn about rules →

Configure the core

Set certificate handling, caching, pipelines, and timeout behavior to fit your use case.

View configuration →

Start in a few minutes

Install the package in your Node.js project:

bash

npm install mitm-core

Create a proxy with your Root CA credentials:

ts

import { readFileSync } from "node:fs";
import { Proxy } from "mitm-core";

const proxy = new Proxy({
  rootCa: {
    cert: readFileSync("./creds/__self__/CA.pem"),
    key: readFileSync("./creds/__self__/key.pem"),
  },
});

await proxy.listen(8001);

Then send a request through it:

bash

curl -x http://127.0.0.1:8001 http://example.com/

HTTPS interception requires a Root CA and a client configured to trust it. Only inspect traffic you own or are authorized to inspect.

DOCUMENTATION

Build with the core.

Start with installation, then explore events, rules, plugins, and configuration.

Read the guide →