Developing Google Apps Script with Claude Code

Google Apps Script (GAS) is widely used for automating Google Workspace tasks like spreadsheet calculations, form notifications, and data transfers. Using clasp (Command Line Apps Script Projects), you can develop and deploy GAS directly from Claude Code.

What is clasp?

clasp is Google’s official CLI tool for GAS. It lets you edit GAS code locally and deploy from the command line.

Benefits with Claude Code:

Describe what you want and Claude Code generates the GAS code
Import existing GAS projects and ask for improvements
Complete development-to-deployment from Claude Code

Setup

1. Install clasp


npm install -g @google/clasp

2. Authenticate with Google


clasp login

A browser window opens. Log in and grant permissions.

3. Enable the Apps Script API

Visit the Apps Script API settings and turn the API On.

Usage

Creating a new GAS project


"Create a GAS script using clasp that aggregates monthly sales data
and runs automatically every Monday"

Importing an existing project


clasp clone <script-id>

Then ask Claude Code:


"Read this GAS code and explain what it does. Then add error handling."

Deploying


clasp push    # Upload code
clasp deploy  # Deploy (create version)

Pre-Deployment Checklist

Never clasp push GAS code generated by Claude Code without reviewing it first.

Check	What to verify
Target data	Is the target sheet/range correct? Could it overwrite other data?
Triggers	Is the execution frequency appropriate? Not running every minute?
Permission scopes	Are unnecessary permissions being requested?
Email sending	Are recipients and content correct? Tested with a test address first?

For GAS that sends emails or calls external APIs, always test with sample data before switching to production data.

Common Use Cases

Goal	Example prompt
Automate spreadsheet calculations	”Create a GAS that aggregates last month’s sales on the 1st”
Form response notifications	”Create a GAS that sends a Slack notification on form submission”
Data transfer	”Create a GAS that copies data from Sheet A to Sheet B”
Bulk email	”Create a GAS that sends emails based on a Sheets list”