Tampery

Tampery is a browser extension to tamper browser requests in flight. It is programmable, which means you could write your own script to intercept, block, or modify browser requests.

<img src="assets/dashboard.png" width="420"> <img src="assets/edit.png" width="420">

Installation

Install it from Chrome Web Store

Notice: Currently we only support Chrome 63+, because dynamic import is used to import your script.

Examples

There are some simple examples to show how it works:

• Change User-Agent
• Remove Google Analytics UTM tokens
• Allow CORS

Usage

Tampery use chrome.webRequest API under the hood. Basically, every script should export an object as default, which has lifecycle, callback, filter and extraInfoSpec as keys.

For example, if we want to change User-Agent in request headers, we could create a script as follows:

const myUserAgent =
  'Mozilla/5.0 (iPhone; CPU iPhone OS 11_0 like Mac OS X) AppleWebKit/604.1.38 (KHTML, like Gecko) Version/11.0 Mobile/15A372 Safari/604.1'

export default {
  lifecycle: 'onBeforeSendHeaders',
  callback: ({ requestHeaders }) => {
    for (var i = 0; i < requestHeaders.length; ++i) {
      // Find the key named `User-Agent` and change its value
      if (requestHeaders[i].name.toLowerCase() === 'user-agent') {
        requestHeaders[i].value = myUserAgent
        break
      }
    }
    return { requestHeaders } // Return to change headers
  },
  filter: {
    urls: ['<all_urls>'], // Specify it takes effect on which URLs
  },
  extraInfoSpec: [
    'requestHeaders',
    'blocking', // Add `blocking` here since we want to change request headers
  ],
}

Checkout examples to understand it quickly.

For more information, see documentation of webRequest API of Chrome and Firefox

License

MIT