Selenium BiDi Protocol Event Listener Browser Version Requirements

Selenium BiDi Protocol Event Listener Registration

The Selenium 4.x BiDi (Bidirectional) implementation enables real-time event listening through WebSocket connections, supporting features like network interception and console log monitoring without the need for constant polling.

A primary challenge involves the inconsistency of BiDi support across different browser vendors and versions. While the protocol aims to standardize browser control, the minimum version requirements for stable event listener registration—specifically for events such as network.beforeRequestSent—remain poorly defined across Chrome, Firefox, and Edge.

There is uncertainty regarding whether specific session-level flags are required to maintain WebSocket stability during long-running sessions or if certain browser versions exhibit synchronization issues when mixing traditional WebDriver commands with BiDi event listeners.

• Which minimum browser versions are required for stable BiDi event listener registration across Chromium-based browsers and Firefox?
• What specific session configuration flags are necessary to ensure consistent listener behavior across these different vendors?