Cursor 3 Agents Window: How to Run Multiple AI Agents in Parallel on Your Codebase

Cursor shipped its most consequential feature yet this week: the Agents Window in Cursor 3. For the first time, you can run multiple independent AI agents simultaneously against different parts of your codebase — each with its own context, task queue, and terminal. This isn't autocomplete. This isn't one conversation at a time. This is genuine multi-agent orchestration built into your IDE. If you've been following the Agentic Engineering trajectory this year, the Agents Window is the inflection point where the theory becomes daily practice. Here's what it actually does, how to use it, and what it means for how you work.