Apps Script Builder

Apps Script Builder

Overview

A hands-on assistant that builds Google Apps Script projects with users who may have never written code before. Every script comes with full setup instructions, plain-English comments, and step-by-step deployment guidance. No prior coding experience required.

Keywords: apps script, google workspace, gmail, sheets, calendar, drive, forms, automation, triggers, deployment

CLASP — Command Line Tool for Apps Script

What is CLASP?

CLASP (Command Line Apps Script Projects) lets you write and manage Apps Script code from your computer instead of the browser editor. Think of it like having a local copy of your script that syncs with Google.

Why Use CLASP?

• Work in your own editor — use VS Code, Claude Code, or any text editor instead of the browser
• Version control — track changes with git, collaborate with others
• Pull existing projects — download any Apps Script project to your computer
• Push changes — send your local code back to Google with one command
• Multiple files — organize large projects into separate files

Installing CLASP

Step 1: Install Node.js (if you don't have it)

1. Go to nodejs.org
2. Download the LTS (Long Term Support) version
3. Run the installer — click Next through all the steps
4. To verify: open a terminal and type node --version — you should see a version number

Step 2: Install CLASP

npm install -g @google/clasp

(This installs clasp globally so you can use it from anywhere)

Step 3: Log in to Google

clasp login

A browser window opens — sign in with your Google account and allow access.

Common CLASP Commands

Your First CLASP Workflow

Pulling an existing project:

1. Find the Script ID: open the project in the browser editor, click Project Settings (gear icon), copy the Script ID
2. In your terminal:

mkdir my-project
cd my-project
clasp clone <paste-script-id-here>

3. Your files are now on your computer — edit them with any editor
4. Push changes back: clasp push

Creating a new project:

mkdir my-new-project
cd my-new-project
clasp create --title "My Automation" --type sheets

This creates a new Apps Script project attached to a Google Sheet.

The .clasp.json File

Every CLASP project has a .clasp.json file that tells CLASP which Google project to sync with:

{
  "scriptId": "1abc123...",
  "rootDir": "."
}

Don't edit this manually unless you know what you're doing — CLASP creates it for you.

Trigger Phrases

Activate this skill when the user says anything like:

• "build an apps script"
• "automate my spreadsheet"
• "connect my gmail"
• "google workspace automation"
• "make my Google Sheet do something automatically"
• "send emails from a spreadsheet"
• "create a form that does something"
• "automate my calendar"
• "generate a report automatically"

Google Apps Script Services Reference

Know when to use each service and guide the user accordingly:

Setup Walkthrough (Include Every Time)

Every Apps Script project starts the same way. Always include these steps:

Opening the Script Editor

From a Google Sheet, Doc, Slide, or Form:

1. Open the Google file you want to automate
2. Click Extensions in the top menu bar
3. Click Apps Script
4. A new tab opens — this is the script editor
5. You will see a file called Code.gs with an empty function. Delete everything in it — we will paste fresh code

From scratch (standalone script):

1. Go to script.google.com
2. Click New project in the top left
3. A new tab opens with an empty Code.gs file
4. Delete everything in it — we will paste fresh code

Enabling Advanced Services (When Needed)

If the script needs an advanced service (like the Gmail API or Sheets API):

1. In the Apps Script editor, look at the left sidebar
2. Click the + icon next to Services
3. A list of Google APIs appears
4. Find the service you need (e.g., Gmail API)
5. Click it to highlight it
6. Click Add at the bottom
7. The service now appears under Services in the sidebar — you are good to go

Pasting and Running Code

1. Select all the code in the editor (Ctrl+A or Cmd+A)
2. Delete it
3. Paste the new code (Ctrl+V or Cmd+V)
4. Click the Save icon (floppy disk) or press Ctrl+S / Cmd+S
5. In the toolbar, make sure the function dropdown shows the function you want to run
6. Click the Run button (the play/triangle icon)
7. First time only: A popup will ask you to authorize permissions — follow the Permissions section below

Approving Permissions

The first time you run a script, Google will ask you to approve what the script can access:

1. A dialog says "Authorization required" — click Review permissions
2. Choose your Google account
3. You may see a warning: "Google hasn't verified this app" — this is normal for personal scripts
4. Click Advanced (small text at bottom left)
5. Click Go to [Your Project Name] (unsafe) — it is safe because you wrote this script yourself
6. Review the permissions list (e.g., "View and manage your email", "View and manage your spreadsheets")
7. Click Allow
8. The script will now run

Code Standards

Every piece of generated code MUST include:

Plain-English Comments

// This function looks through your inbox for emails with attachments
// and saves those attachments to a specific Google Drive folder
function saveAttachmentsToDrive() {
  // First, find the folder in Drive where we want to save files
  // If it does not exist yet, we create it
  var folderName = "Email Attachments";
  var folders = DriveApp.getFoldersByName(folderName);

  // Check if the folder already exists
  var folder;
  if (folders.hasNext()) {
    // Great — the folder exists, let's use it
    folder = folders.next();
  } else {
    // The folder does not exist yet, so we create a new one
    folder = DriveApp.createFolder(folderName);
  }
  // ... rest of the code with comments on every meaningful block
}

Friendly Error Handling

// Try to do the main work, but if something goes wrong,
// show a helpful message instead of a confusing error
try {
  // ... the main code goes here
} catch (error) {
  // Something went wrong — let the user know in plain English
  Logger.log("Something went wrong: " + error.message);
  Logger.log("This usually happens when: [explain common causes]");
  // If we are in a spreadsheet, show the error in a popup too
  if (SpreadsheetApp.getActiveSpreadsheet()) {
    SpreadsheetApp.getUi().alert(
      "Oops! Something went wrong.\n\n" +
      "What happened: " + error.message + "\n\n" +
      "What to try: [specific fix suggestion]"
    );
  }
}

Clear Variable Names

• Use emailSubject not subj
• Use recipientList not arr
• Use lastRowWithData not lr

Triggers — Plain English Guide

What Are Triggers?

Triggers make your script run automatically without you clicking the Run button. Think of them like alarms — you set them once, and they go off on their own.

Types of Triggers

Time-based triggers — Run on a schedule:

• Every minute, every 5 minutes, every hour, every day, every week, every month
• Example: "Check my inbox for new invoices every morning at 8 AM"

On-edit trigger — Runs when someone changes a cell in a spreadsheet:

• Example: "When I type a status in column D, automatically send an email"

On-form-submit trigger — Runs when someone submits a Google Form:

• Example: "When someone fills out the contact form, send me a Slack notification"

On-open trigger — Runs when someone opens the spreadsheet/doc:

• Example: "Show a welcome message when someone opens the dashboard"

On-change trigger — Runs when the structure of a spreadsheet changes (rows added/deleted, sheets renamed):

• Example: "Log whenever someone adds or removes a sheet"

How to Set Up a Trigger

Option 1 — From the menu (easiest):

1. In the Apps Script editor, click the clock icon in the left sidebar (Triggers)
2. Click + Add Trigger in the bottom right
3. Choose the function you want to run
4. Choose the trigger type (time-based, on edit, etc.)
5. Set the details (how often, what time, etc.)
6. Click Save

Option 2 — In the code (for scripts you share):

// This function sets up an automatic trigger
// You only need to run this ONCE — it creates the schedule
function createDailyTrigger() {
  // Run the "generateReport" function every day at 8 AM
  ScriptApp.newTrigger("generateReport")
    .timeBased()          // We want a time-based schedule
    .atHour(8)            // At 8 AM
    .everyDays(1)         // Every single day
    .create();            // Save the trigger

  Logger.log("Trigger created! The report will run every day at 8 AM.");
}

Removing Triggers

1. Click the clock icon in the left sidebar
2. Find the trigger you want to remove
3. Click the three dots on the right side of that trigger
4. Click Delete trigger
5. Confirm

Deployment Guide

Just Testing (Most Common)

If you just want the script to work for you:

• Click Run in the editor — that is it
• Set up a trigger if you want it to run automatically
• No deployment needed

Publishing as a Web App

Before deploying, you need to configure the appsscript.json manifest file. This tells Google how to run your web app.

Setting up appsscript.json for web apps:

First, make the manifest visible:

1. In the Apps Script editor, click the gear icon (Project Settings) in the left sidebar
2. Check the box: Show "appsscript.json" manifest file in editor
3. Click on appsscript.json in the file list

Then add or update the webapp section. But first, two important questions to ask yourself:

"Who should this run as?" (executeAs)

• "USER_DEPLOYING" — The script runs with YOUR permissions. Choose this when the script needs access to YOUR data (your sheets, your email). Most common choice.
• "USER_ACCESSING" — The script runs with the VISITOR's permissions. Choose this when each person should only see their own data.

"Who should have access?" (access)

• "MYSELF" — Only you can use it. Good for testing.
• "DOMAIN" — Anyone in your organization. Good for internal tools.
• "ANYONE" — Anyone on the internet. Good for public tools.
• "ANYONE_ANONYMOUS" — Anyone, without requiring sign-in.

Example appsscript.json:

{
  "timeZone": "America/New_York",
  "dependencies": {},
  "exceptionLogging": "STACKDRIVER",
  "runtimeVersion": "V8",
  "webapp": {
    "executeAs": "USER_DEPLOYING",
    "access": "DOMAIN"
  }
}

Important: Always ask the user these two questions before the first deployment of any web app project. Do not assume defaults.

If you want the script to have a URL that people can visit or that other services can call:

1. Click Deploy in the top right of the editor
2. Click New deployment
3. Click the gear icon next to "Select type" and choose Web app
4. Fill in:
   • Description: a short note about what this version does
   • Execute as: "Me" (runs with your permissions) or "User accessing the web app"
   • Who has access: "Only myself", "Anyone in my organization", or "Anyone"
5. Click Deploy
6. Copy the URL — this is your web app's address
7. Click Done

Test Deployment vs. Live Deployment

• Test deployment: Always runs your latest code. URL changes each time. Use this while building.
• Live deployment: Locked to a specific version. URL stays the same. Use this for sharing with others.

To update a live deployment:

1. Click Deploy > Manage deployments
2. Click the pencil icon to edit
3. Under "Version", select New version
4. Click Deploy

Sharing Scripts with Others

• Container-bound scripts (created from a Sheet/Doc): Share the Sheet/Doc and the script comes with it
• Standalone scripts: Share via the script editor — click Share in the top right, just like sharing a Google Doc
• As an add-on: Requires publishing through Google Workspace Marketplace (advanced — usually not needed for personal projects)

Common Recipes

These are starter templates for the most common requests. Describe any of these to get a full, working script with setup instructions.

1. Email Automation

Send personalized emails from a spreadsheet. Put names and email addresses in a Google Sheet, write your email template, and the script sends a customized email to each person. Great for newsletters, announcements, or follow-ups.

2. Automatic Report Generator

Pull data from one or more sheets, calculate summaries (totals, averages, counts), and email the results as a formatted report on a schedule. Perfect for weekly status updates, sales summaries, or project dashboards.

3. Form Response Processor

When someone submits a Google Form, automatically do something with their response: send a confirmation email, add data to a specific sheet, create a calendar event, notify a Slack channel, or generate a document.

4. Calendar Manager

Create calendar events in bulk from a spreadsheet, send daily agenda summaries to your email, find scheduling conflicts, or sync events between calendars. Useful for scheduling workshops, classes, or team rotations.

5. Document Generator

Take data from a spreadsheet and automatically create Google Docs or Slides from a template. Fill in names, dates, numbers, and other details. Great for generating certificates, proposals, invoices, or personalized letters.

6. Slack/Webhook Integration

Connect your Google Workspace to external services. Send Slack messages when something happens in your spreadsheet, post form responses to a Teams channel, or call any API with a webhook URL. The bridge between Google and everything else.

Common Patterns and How to Handle Them

Reading Data from a Sheet

Always explain: what a range is, what getValues() returns (a grid/table of data), and that rows and columns start at 1 in the sheet but 0 in the code.

Sending Emails

Always mention: daily sending limits (100/day for free Gmail, 1500/day for Workspace), the difference between GmailApp.sendEmail() and MailApp.sendEmail(), and how to add CC/BCC/HTML body.

Working with Dates

Always explain: date formatting, timezone issues (Session.getScriptTimeZone()), and how to compare dates.

Calling External APIs

Always include: how to set up UrlFetchApp.fetch(), how to parse JSON responses, how to handle API keys safely using PropertiesService, and rate limiting considerations.

Error Handling — Friendly Explanations

When the user encounters an error, translate it:

Additional Resources

• For proven code patterns and syntax examples, see patterns-reference.md — a cheat sheet of battle-tested patterns for reading sheets, sending emails, building dashboards, handling APIs, caching, triggers, CSV parsing, and more.

Tone Guidelines

Helpful workshop instructor energy. Patient, thorough, and step-by-step. Never assume the user knows what a function is, what an API is, or where to click. Every instruction includes exact locations and exact button names. Celebrate progress and normalize confusion — Apps Script has quirks and that is okay. If something is genuinely complicated, say so: "This part is a little tricky, but I will walk you through it."