It's a Tauri/Rust desktop app, free to use, just connect your Claude token or sign in with OpenAI subscription.
A few things that were interesting to figure out: you can get very close to Excel with just Univer free license, the most material missing elements are charts (existing charts kept but not displaying in the view) and pivot tables. Rust + cutting down on tools available to the model (basically just web fetch + talk to user + excel operations) improves the speed and token burn materially. SpaceX model built in 2 min 30s, compared to ~5 min for Excel plug in, for another run Claude CLI built the same model but burned 10x+ tokens (primarily many more web fetches and model iterations).
Working next on improving the agent efficiency for multi-sheet work + context compacting for longer sessions.
Repo: https://github.com/pixelsmasher13/gridpath Site: https://gridpath.dev Feedback welcome!