stagehand-python@4.2.0a0.dev1524: feat : add WebMCP tools added/removed event hooks ( 2916)

Browserbase Stagehand releases published stagehand-python@4.2.0a0.dev1524: feat : add WebMCP tools added/removed event hooks ( 2916). This release-watch entry was generated from the project's official GitHub release feed and is kept separate from human-reviewed editorial analysis. Release notes: why users need a way to subscribe to events that fire when webmcp tools were added or removed from a page note: this PR ended up a lot larger than just adding two hooks because WebMCP.enable causes Chrome to emit toolsAdded events for tools that already exist (docs here ). ie, the WebMCP.toolsAdded event would fire every time someone called page.tools() . therefore, we needed to manage some state, and essentially keep a registry of tools that have been added/removed. with the changes from this PR, page.tools() reads that registry instead of enabling WebMCP again. a lot of the code here is related to state synchronization, because the registry now needs to be kept in sync across navigation and iframe detachment etc.. what changed added onToolsAdded() / onToolsRemoved() in TypeScript, on tools added() / on tools removed() in Python, and OnToolsAdded() / OnToolsRemoved() in Go reused the…

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