Raycast dropped a technical deep dive last week about rebuilding their desktop app from scratch. The headline was about going cross-platform. The buried lede was something much more interesting. Their new architecture has four layers: a native host shell, a React frontend, a Node.js backend for all business logic, and a Rust core for data and indexing. These layers communicate through typed IPC with compile-time guarantees across all four runtimes. Here is the part that stopped me mid-scroll: business logic no longer lives inside the UI layer. It lives in a separate process. The UI calls it. Extensions call it. And nothing stops an external process, including an AI agent, from calling it too. The user clicking "search files" and an agent issuing a search command travel through the same path. The backend does not know which one initiated the request. It does not need to know. This is a deceptively simple idea with real weight behind it. UI and AI agents become equal citizens of the application.…