The interesting bits:
- Three-panel layout: Monaco code editor, live preview, and Claude chat side-by-side
- AST-based code navigation: double-click text in the preview to jump to the exact line in the editor
- Multiple AI "agents" with full conversation rollback (inspired by Cursor's chat history)
- Project/email organization with a file-system-like structure
- Everything runs locally – your API key and templates never leave your browser
- I built the whole thing in a day: maybe 5hrs. Simon Willison is onto something with the personal software thing.
Tech stack: React, Vite, TypeScript, Zustand, MJML, Monaco Editor, and Claude Sonnet.
Fun fact: I prototyped the entire thing in ~10 minutes using Cursor and Claude Sonnet 4.5, which was a fun experiment in AI-assisted development. The hardest part was getting the AST parsing right for the code navigation feature.
Open to feedback!