The .xlsx file itself stays on disk — no GridPath cloud, no upload, no third-party server in the middle. What does flow to the LLM provider you've signed in with (Anthropic for Claude, OpenAI for ChatGPT) is your prompt, sheet structure, and whatever cells the agent reads or writes during the run. Same shape and same privacy terms as using that provider's product directly. See Privacy for the long version.

GridPath connects to your Claude or ChatGPT subscription — you pay the LLM provider whatever you already pay them, and nothing extra to us.

Yes — but with one honest caveat. We keep the original workbook in memory using ExcelJS and only patch the cells the agent actually changes on save. That means everything else — charts, conditional formatting rules, named ranges, data validation, merged cells, drawings, freeze panes, pivot tables, themes — flows through the round-trip untouched. Open the file in Excel after and it looks exactly like it did before, plus your new edits.

The caveat: GridPath's in-app grid (built on Univer) doesn't visually render charts, conditional-formatting coloring, drawings, or pivot tables while you're editing. They're fully intact in the file — just not painted on screen inside our app. The agent still respects merged cells, freeze panes, and named ranges natively. If your workflow needs to see chart updates live, do that pass in Excel; if it's structural / formula work, GridPath is faster.

Three ways. (1) Reject the proposed batch before it commits — nothing touches the file. (2) ⌘Z to undo accepted changes within the session. (3) After save, we keep a .bak with the previous state for one-step recovery, even after reopening.

Excel Copilot is a single-turn assistant inside Excel. GridPath runs a multi-turn agent loop — fetch web data, write 58 rows, apply 64 formatting ops, fix its own formula errors — across 10–15 tool calls per prompt, until the model is genuinely done. Plus you pick the underlying LLM and review every edit before it lands.

.xlsx today. .xls, .csv, and Google Sheets via API are on the roadmap.

Yes. Cross-sheet references (=Sheet2!A1) work natively, and renaming a sheet auto-updates references in other sheets. External workbook links (=[Other.xlsx]Sheet1!A1) survive as cached values but don't recompute live — same limit Google Sheets has.

macOS (Apple Silicon, macOS 12+) and Windows (10/11). Linux is on the roadmap. Source available for security review on request.