chromex

Chromex is a Chrome side-panel extension that connects your browser to OpenAI's Codex through a local native messaging bridge. Summarize pages, work across tabs and screenshots, edit images, transcribe voice, and run browser-control workflows with visible in-page indicators. MIT licensed.

Setup is heavier than a typical extension: clone the repo, `npm install && npm run build`, run `install-native-host.mjs`, then load the unpacked extension at `chrome://extensions`. The architecture (Chrome extension to native host to local bridge to codex app-server) keeps your API key local; raw keys aren't stored in extension storage.

Pick this if you live in Chrome, already run Codex, and want one assistant that sees the page you're on. Solo: free, you pay only for Codex tokens. Small teams: same. Large teams or non-Codex shops: skip; this is built around Codex specifically.

The catch: Codex-only. Switch to Claude or Gemini for your CLI agent and Chromex doesn't follow. The native bridge is only as polished as the project, which is small and early. For a more mature Chrome AI assistant, Sider and Monica have more features and broader model support.