BiDirectional Functionality

Selenium is working with browser vendors to create the WebDriver BiDirectional Protocol as a means to provide a stable, cross-browser API that uses the bidirectional functionality useful for both browser automation generally and testing specifically. Before now, users seeking this functionality have had to rely on with all of its frustrations and limitations.

The traditional WebDriver model of strict request/response commands will be supplemented with the ability to stream events from the user agent to the controlling software via WebSockets, better matching the evented nature of the browser DOM.

As it is not a good idea to tie your tests to a specific version of any browser, the Selenium project recommends using WebDriver BiDi wherever possible.

However, until the specification is complete there are many useful things that CDP (Chrome DevTools Protocol) offers. To help keep your tests independent and portable, Selenium offers some useful helper classes as well. At the moment, they use the CDP, but soon it could be done using WebDriver BiDi.