Add a proposed roadmap for Bidi adoption and Classic deprecation

Author: shs96c

website_and_docs/content/blog/2025/bidi-roadmp.md

@@ -0,0 +1,63 @@
+---
+title: "Roadmap for adopting WebDriver Bidi"
+linkTitle: "Proposed roadmap for adopting WebDriver Bidi and deprecating WebDriver Classic"
+date: 2025-03-11
+tags: ["selenium"]
+categories: []
+author: Diego Molina [@diemol](https://www.diemol.com)
+description: >
+  A roadmap for how and when Selenium will adopt WebDriver Bidi and deprecate WebDriver Classic.
+---
+
+Roadmap
+
+In order to automate browsers, Selenium builds upon open standards
+developed by the W3C. The first of these is [W3C
+WebDriver](https://w3c.github.io/webdriver/), which was derived from
+the original wire protocol used by Selenium 2, and this has been
+powering our tests for many years. It works by using a
+"request/response" model: the Selenium APIs send a command, the
+browser executes that, and sends back a response which we process,
+before we send another command. At any one time, there's only one
+command being executed.
+
+However, the Web evolves, and so does the WebDriver standard. The next
+evolution of the W3C standard for browser automation is called
+[WebDriver Bidi](https://w3c.github.io/webdriver-bidi/). This is a
+more sophisticated protocol, leaning heavily on the lessons learned
+from the [Chrome DevTools
+Protocol](https://chromedevtools.github.io/devtools-protocol/) (CDP),
+and the key difference is that rather than following a
+"request/response" model, Bidi now uses an event-based model. While
+this allows the Selenium APIs to ask the browser to execute actions,
+the browser can now send information back at any time to our
+APIs. This allows a more dynamic style of testing than we've been able
+to achieve with the original WebDriver protocol.
+
+One goal of Bidi is that it should be possible to use it for
+everything that the original spec (now commonly referred to as
+"WebDriver Classic" or just "Classic") could do. It seems natural that
+if this is the case, we should consider phasing out the Classic
+protocol and only relying on Bidi, just as we phased out support for
+the original "[JSON Wire
+Protocol](https://www.selenium.dev/documentation/legacy/json_wire_protocol/)". Just
+as with that transition, we will do this carefully so that our users
+(you\!) shouldn't notice the change.
+
+How will we go about this? While this plan can still change, the approach we are taking is:
+
+1. Focus our development time on Bidi.  
+2. Use Bidi to add extra features, such as network interception and capturing JS logs.  
+3. Start to use Bidi in preference to Classic where possible (for example, for navigating to new URLs, or for finding elements)  
+4. Once the Bidi spec becomes a [Candidate Recommendation](https://www.w3.org/standards/types/#x4-2-candidate-recommendation), cease development of the Classic implementation and mark it deprecated.  
+5. Once the Bidi spec becomes a Recommendation, start phasing out Classic support. This will mean that in the next major Selenium release (that is, Selenium 5), only the Java bindings will retain optional legacy Classic support.  
+   
+
+The developers of the Selenium project have already started the first
+two steps, and we shall soon start on the third.
+
+The Bidi spec is now moving forwards quite rapidly, and the first
+public working draft has been published. There are multiple
+implementations of the spec already available, and while it’s being
+adopted by Selenium, it’s also being used by other tools such as
+Puppeteer, Cypress, and even Playwright.