sniff

A simple HTTP and WebSocket sniffer for WebExtensions.

Documentation

HTTP

Import sniffHttp in your background script and provide it with a callback:

import { sniffHttp } from 'sniff';

sniffHttp((msg) => {
  if(msg.targetUrl === ""http://www.example.com/dwarfs") {
    console.log("Found dwarfs!");
  } else {
    console.log("No dwarfs here.");
  }
})

Read more about the callback's msg here.

WebSocket

Import and call initWsSniffer in your content script:

import { initWsSniffer } from 'sniff';

initWsSniffer();

Import sniffHttp in your background script and provide it with a callback:

import { sniffWs } from 'sniff';

sniffWs((msg) => {
  if(msg.targetUrl === ""http://www.example.com/dwarfs") {
    console.log("Found dwarfs!");
  } else {
    console.log("No dwarfs here.");
  }
})

Read more about the callback's msg here.

Sniffed Message

All sniffed messages have geometry

interface SniffedMessage<T> {
  data: T;
  srcUrl: string;
  targetUrl: string;
  tabId: number;
}

where

• data is the body of HTTP response or WebSocket message.
• srcUrl is the location of the request.
• targetUrl is the target of the request.
• tabId is the tab the request was sent from.

E.g., if you open a new browser and navigate to http://www.example.com , which makes a call to http://www.example.com/dwarfs, you would get a response of:

{
  data: "[\"Sleepy\",\"Dopey\",\"Bashful\",\"Grumpy\",\"Happy\",\"Sneezy\",\"Doc\"]",
  srcUrl: "http://www.example.com";
  targetUrl: "http://www.example.com/dwarfs";
  tabId: 0;
}