In Part 1 we covered the browser infrastructure layer. The plumbing. Remote browsers, CDPs, the headless Chromium sprawl. If you missed it, go read that first because this one builds directly on top of it. Now we're going up a level. The frameworks. The SDKs. The bits that actually let your agent do things in a browser instead of just staring at one. Same lens as Part 1: this is about giving your coding agents the tools for a closed loop of research, implementation, and validation. Not consumer agentic browsers. And here's where it gets properly interesting, because there's a civil war happening in this space and most people haven't noticed yet. On one side: DOM-first. On the other: vision-first. And in the middle, a messy hybrid zone where the most pragmatic engineering is happening. The Architecture Split That Defines Everything Before we get into individual tools, you need to understand the fundamental schism. When an AI agent needs to interact with a web page, it has to see the page somehow.…