Cellmate
Cellmate — Google Sheets add-on
Cellmate is a Google Sheets add-on that lets you run AI prompts in your spreadsheet using your own API key. Install it from the Google Workspace Marketplace, connect any OpenAI-compatible key, and call AI from the =cellmate() formula — your key, your provider, your bill.
$25/month after a 7-day free trial (no card) · $5/mo off for each active paying subscriber (up to $25). Help and billing live in the Sheets sidebar.
What is Cellmate?
Cellmate is a Google Sheets add-on that lets you run AI prompts in your spreadsheet using your own API key. Write =cellmate() in a cell, run saved commands from the sidebar, and scope which ranges the add-on may read or write (with undo for AI edits). Cellmate does not sell AI tokens — usage is billed by the OpenAI-compatible provider you choose.
Privacy Policy and Terms of Service are linked in the site footer and apply to this website and the Cellmate Sheets add-on. Use of raw or derived user data received from Workspace APIs adheres to the Google User Data Policy, including the Limited Use requirements — see our Privacy Policy.
Works with any OpenAI-compatible endpoint, including
Everything an AI formula should be
Built for spreadsheet work: a simple formula, scoped edits you can undo, and AI billed by the provider you already use.
Bring your own key
Connect any OpenAI-compatible API with your own key in the add-on. You pick the provider and pay them directly for usage.
=cellmate() in any cell
Call your model 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.
Install from Marketplace
Get Cellmate from the Google Workspace Marketplace, then open it from Extensions in any spreadsheet.
Add your API key
Paste in a key from any OpenAI-compatible provider in the Cellmate sidebar. It's saved with your Google account via User Properties.
Write =cellmate()
Use the formula in a cell, or select a range and run a saved command. Pricing, docs, and FAQ live in the sidebar.
Your key. Your provider.
Cellmate doesn't sell AI tokens. You bring an API key from any OpenAI-compatible provider, configure it in the add-on, and use =cellmate() in your sheet.
- Add your API key once in the Cellmate sidebar — it's stored in Google User Properties on your account.
- Use OpenAI, Groq, OpenRouter, a self-hosted endpoint, or any other OpenAI-compatible API.
- Cellmate is $25/month after a 7-day free trial (no card required). $5/mo off for each active paying subscriber (up to $25).
- AI usage is billed by your provider, not by Cellmate. Pricing, docs, and FAQ are in the sidebar.
In practice
Ready to bring AI into your own spreadsheet?
Install Cellmate from the Marketplace, connect your key, and write your first =cellmate() formula in a few minutes.