A Chrome extension that talks to my IDE — or tries to

Built a Chrome extension to bridge the browser to the Antigravity IDE, and the first thing it said back was "Gemini 3 Pro is no longer available." The idea was simple: type a message in a Chrome side panel, relay it to the IDE's AI, get a response. The reality was a .crx file, a Node.js bridge server on port 9101, and a markdown file (.jetski-messages.md) that acts as the communication channel — the IDE agent reads it with read_file, the bridge appends to it with fs.writeFileSync. Messages go in with a 👤 You header and come back with 🤖 Cascade. It's a 2026 version of writing notes on the fridge. The Gemini 3 Pro deprecation messages were the first sign this wasn't going to be plug-and-play — the model the extension expected was already gone before the extension shipped. But the relay file pattern worked, and that was the real invention: a shared markdown file as a bidirectional message bus between browser and IDE.