This is a fork of the browser extension WAIncognito from tomer8007. In addition to disabling read receipts and presence updates on WhatsApp Web, this also adds a battery percentage indicator.
To install, clone this repository into a directory, and add it to Chrome using the 'Load unpacked extension' option when developer mode is turned on.
This extension works by intercepting the WebSocket frames between chrome and WhatsApp's servers using a modified WebSocket constructor (see wsHook).
Those frames are then decrypted if needed using the local encryption keys (stored in localStorage), and decoded from a binary form using a javascript code from WhatsApp's original implementation.
The resulting "nodes" are then simply checked to see if WhatsApp tries to send out a read or presence action, and if so, the extension blocks it and fakes a failure response from the server.
WhatsApp Web receives the battery percentage of the device upon initial connection and periodically to determine whether to display a "Phone Battery Low" message or not. This fork displays the raw battery percentage and charging status at all times.
The main code of the extension is located in core/interception.js and in core/ui.js.
Other files inside the core folder deal with the infrastructure that makes the interception and the decoding works. There is also an additional parsing/ code for parsing messeges (such as message_types.js) that is rarely used in the extension.
background.js mainly keeps track of the saved prefrences using localStorage.
If you want to see what kind of messages WhatsApp is sending and receiving over WebSocket in real-time, you can type WAdebugMode = true in the javascript console. Incoming and outgoing payloads (after decryption) will be printed out.
No data is ever transmitted to anywhere. Privacy policy here.
If you want to use this extension in Firefox, you can load it using the devloper page as explained in issue #38