Cellmate
your spreadsheet's AI cellmate
Cellmate adds a single formula, =cellmate(), to Google Sheets — powered by whichever OpenAI-compatible provider you already trust. No proxy, no shared key, no surprise line item on someone else's bill.
$25/month after trial · up to $25 off with referrals · BYOK
Works with any OpenAI-compatible endpoint, including
Everything an AI formula should be
Cellmate is built for spreadsheet people who don't want to hand their data — or their API key — to a third-party server.
Bring your own key
Connect any OpenAI-compatible API with your own key. Cellmate never proxies your requests or stores your key on our servers.
=cellmate() in any cell
Call your model straight from a formula. Reference cells and ranges as inputs, and let results flow through your spreadsheet like any other function.
Scope + undo
Choose exactly which range Cellmate can read and write before it runs. Every AI edit is tracked, so you can undo it in one click.
Custom commands
Save your favorite prompts as reusable commands — 'Summarize', 'Fix grammar', 'Extract line items' — and run them from a menu instead of retyping.
How Cellmate works
Three steps between installing the add-on and your first AI-generated cell.
Add your API key
Paste in a key from any OpenAI-compatible provider. It's stored in your Google account's private User Properties — never on a Cellmate server.
Write =cellmate()
Use the formula directly in a cell, or select a range and choose a saved command. Cellmate sends the request straight to your provider.
Review, scope, undo
Set boundaries on what Cellmate can touch, watch results land in your sheet, and roll back any change instantly if it's not quite right.
No proxy. No middleman.
Most AI add-ons route your prompts — and your data — through someone else's server. Cellmate doesn't. Your sheet talks directly to your chosen provider.
- Your API key is stored in Google User Properties, tied to your account, never on a Cellmate server.
- Sheet contents and prompts travel from Google Sheets straight to your provider's API.
- Cellmate's servers never receive your sheet data or your key — there's nothing for us to see.
Data flow
Ready to bring AI into your own spreadsheet?
Follow the setup guide, connect your key, and write your first =cellmate() formula in a few minutes.