Home › Rules › Google Sheets automation (Apps Script)

Google Sheets automation (Apps Script) rules: AGENTS.md, CLAUDE.md & Cursor rules

Free to copy. File formats checked against the official docs on Oct 19, 2026 (sources).

• Automation & scripts
• Claude Code
• OpenAI Codex
• Cursor
• GitHub Copilot

Apps Script can rewrite a whole spreadsheet in a second. These rules make the AI test on a copy, batch its reads and writes, and stay inside Google's limits.

Stack these rules assume: Google Apps Script bound to a Google Sheet (optional: clasp for local editing). Different stack? Customize it in the generator.

Quick start

1. Copy the AGENTS.md below into your project's root folder.
2. Fill in the three [bracketed] lines under "Project". Delete any rule that doesn't fit.
3. Start your first chat with: "Read AGENTS.md and follow it for this whole session."

AGENTS.md (works across tools)

Read by OpenAI Codex, Cursor, GitHub Copilot, Claude Code (when there's no CLAUDE.md) and many other agents.

# AGENTS.md: Google Sheets automation (Apps Script)

Instructions for AI coding agents working on this project. Replace anything in [brackets].

## Project
- What it is: [one sentence: what you are building and who it is for]
- Stack: Google Apps Script bound to a Google Sheet (optional: clasp for local editing)
- Version 1 only needs to: [the ONE thing it must do]

## Commands
- Open the editor: In the Sheet: Extensions → Apps Script
- Optional: install clasp to edit locally: `npm install -g @google/clasp`
- Pull the script to your computer: `clasp clone <scriptId>`
- Push local changes: `clasp push`

## Project rules
- Develop and test against a copy of the sheet. Ask before running anything on the real one.
- Read and write in batches (getValues / setValues on whole ranges), not cell by cell in a loop.
- Look up columns by header name, not by fixed column letters.
- Keep runs short and process big sheets in chunks. Tell me if a job might exceed Apps Script's execution time limit.
- Ask before adding triggers (time-driven or on-edit) and explain what each one does.
- Request only the OAuth scopes the script needs.

## How to work
- Do one task per request. If my request is really several tasks, list them and do only the first.
- Before writing code, give a 3-line plan: what you'll change, which files, and how I'll test it.
- Make the smallest change that works. Don't refactor, rename, or reformat code I didn't ask about.
- Ask before adding a dependency, deleting or moving files, changing the data/database structure, or touching more than 3 files.
- If you're not sure a library, API, or setting exists in the version we use, say so and check the installed package or the docs instead of guessing.
- Never say something works unless you ran it or I confirmed it. Report errors exactly.
- Secrets (API keys, tokens, passwords) live only in environment variables or a .env file listed in .gitignore. Never print, hardcode, or commit them.
- Never run destructive commands (rm -rf, git reset --hard, force-push, dropping tables) without asking first.

## Finish every task with
1. What changed (list the files).
2. How to run or test it in under a minute, and what I should see.
3. A suggested git commit message.

Why each rule exists

• Google Sheets automation (Apps Script) ruleDevelop and test against a copy of the sheet. Ask before running anything on the real one.Why: There's no git for spreadsheet data. A copy is your undo button.
• Google Sheets automation (Apps Script) ruleRead and write in batches (getValues / setValues on whole ranges), not cell by cell in a loop.Why: Cell-by-cell calls are extremely slow and hit execution time limits fast.
• Google Sheets automation (Apps Script) ruleLook up columns by header name, not by fixed column letters.Why: Someone will insert a column, and letter-based code will write to the wrong place.
• Google Sheets automation (Apps Script) ruleKeep runs short and process big sheets in chunks. Tell me if a job might exceed Apps Script's execution time limit.Why: Apps Script stops long-running executions, which can leave a job half done.
• Google Sheets automation (Apps Script) ruleAsk before adding triggers (time-driven or on-edit) and explain what each one does.Why: Triggers run without you watching, so they deserve a second look.
• Google Sheets automation (Apps Script) ruleRequest only the OAuth scopes the script needs.Why: Users see every scope on the authorization screen. Fewer scopes, more trust.
• How to workDo one task per request. If my request is really several tasks, list them and do only the first.Why: Big multi-part requests are where AI tools change 12 files and you can't tell which change broke things.
• How to workBefore writing code, give a 3-line plan: what you'll change, which files, and how I'll test it.Why: A plan you can read in 10 seconds catches the wrong approach before it costs you an hour or a pile of credits.
• How to workMake the smallest change that works. Don't refactor, rename, or reformat code I didn't ask about.Why: Drive-by "cleanups" are the #1 cause of "it was working yesterday".
• How to workAsk before adding a dependency, deleting or moving files, changing the data/database structure, or touching more than 3 files.Why: These are the changes that are hard to undo. One quick question is cheaper than a rollback.
• How to workIf you're not sure a library, API, or setting exists in the version we use, say so and check the installed package or the docs instead of guessing.Why: AI tools confidently invent functions and config options. Making it check is the cure.
• How to workNever say something works unless you ran it or I confirmed it. Report errors exactly.Why: "Should work now" isn't a test result. You want facts, not optimism.
• How to workSecrets (API keys, tokens, passwords) live only in environment variables or a .env file listed in .gitignore. Never print, hardcode, or commit them.Why: Leaked keys get found by bots within minutes of a public push. This rule is the cheapest insurance you'll ever buy.
• How to workNever run destructive commands (rm -rf, git reset --hard, force-push, dropping tables) without asking first.Why: One bad command can delete the only copy of your work.
• Finish every task withWhat changed, how to test it, and a commit message.Why: This turns every task into a checkpoint: you test it, you commit it, and you always have a last good version to go back to.

Use it as CLAUDE.md (Claude Code)

Pick one:

1. Do nothing. Current Claude Code versions read AGENTS.md when the project has no CLAUDE.md. Run /memory in a session to check it loaded.
2. Import it (best if you want Claude-only extras, or you're on an older Claude Code). Create CLAUDE.md next to AGENTS.md:

@AGENTS.md

## Claude Code
- Use plan mode before any change that touches more than 3 files.

3. Claude only? Save the same AGENTS.md text as CLAUDE.md instead. Don't keep two separate copies; they drift apart.

Heads-up: if a project has both files and CLAUDE.md doesn't import AGENTS.md, Claude Code reads only CLAUDE.md by default. More in AGENTS.md vs CLAUDE.md.

Use it as Cursor rules (.cursor/rules/*.mdc)

Cursor reads AGENTS.md too, so the file above already works. If you prefer Cursor's own Project Rules, split it into two .mdc files. The .mdc extension and frontmatter are required; Cursor ignores plain .md files in .cursor/rules.

---
description: Project overview and working rules for Google Sheets automation (Apps Script)
alwaysApply: true
---

# Google Sheets automation (Apps Script)

Instructions for AI coding agents working on this project. Replace anything in [brackets].

## Project
- What it is: [one sentence: what you are building and who it is for]
- Stack: Google Apps Script bound to a Google Sheet (optional: clasp for local editing)
- Version 1 only needs to: [the ONE thing it must do]

## Commands
- Open the editor: In the Sheet: Extensions → Apps Script
- Optional: install clasp to edit locally: `npm install -g @google/clasp`
- Pull the script to your computer: `clasp clone <scriptId>`
- Push local changes: `clasp push`

## How to work
- Do one task per request. If my request is really several tasks, list them and do only the first.
- Before writing code, give a 3-line plan: what you'll change, which files, and how I'll test it.
- Make the smallest change that works. Don't refactor, rename, or reformat code I didn't ask about.
- Ask before adding a dependency, deleting or moving files, changing the data/database structure, or touching more than 3 files.
- If you're not sure a library, API, or setting exists in the version we use, say so and check the installed package or the docs instead of guessing.
- Never say something works unless you ran it or I confirmed it. Report errors exactly.
- Secrets (API keys, tokens, passwords) live only in environment variables or a .env file listed in .gitignore. Never print, hardcode, or commit them.
- Never run destructive commands (rm -rf, git reset --hard, force-push, dropping tables) without asking first.

## Finish every task with
1. What changed (list the files).
2. How to run or test it in under a minute, and what I should see.
3. A suggested git commit message.

The project rules only attach when a matching file is in the chat (globs with alwaysApply: false). Want them on all the time? Change it to alwaysApply: true.

---
globs: **/*.gs, **/*.js
alwaysApply: false
---

# Project rules: Google Sheets automation (Apps Script)

- Develop and test against a copy of the sheet. Ask before running anything on the real one.
- Read and write in batches (getValues / setValues on whole ranges), not cell by cell in a loop.
- Look up columns by header name, not by fixed column letters.
- Keep runs short and process big sheets in chunks. Tell me if a job might exceed Apps Script's execution time limit.
- Ask before adding triggers (time-driven or on-edit) and explain what each one does.
- Request only the OAuth scopes the script needs.

Use either AGENTS.md or these .mdc files, not both, so you don't send the same rules twice. See Cursor rules vs AGENTS.md.

Related

• AGENTS.md, CLAUDE.md and Cursor rules formats explained