Google Apps Script
Overview
Cloud-based JavaScript platform for automating Google Workspace services. Server-side V8 runtime with automatic OAuth integration across Sheets, Docs, Gmail, Drive, Calendar, and more.
When to Use This Skill
Invoke this skill when:
- Automating Google Sheets operations (reading, writing, formatting)
- Creating or editing Google Docs programmatically
- Managing Gmail messages and sending emails
- Working with Google Drive files and folders
- Automating Google Calendar events
- Implementing triggers (time-based or event-based)
- Building custom functions for Sheets
- Creating Google Workspace add-ons
- Handling OAuth scopes and authorisation
- Making HTTP requests to external APIs with UrlFetchApp
- Using persistent storage with PropertiesService
- Implementing caching strategies with CacheService
- Optimising performance with batch operations
- Debugging Apps Script code or authorisation issues
Core Services
- SpreadsheetApp - Google Sheets automation (read, write, format, data validation)
- DocumentApp - Google Docs creation and editing
- GmailApp & MailApp - Email operations (send, search, manage labels)
- DriveApp - File and folder management, sharing, permissions
- CalendarApp - Calendar events, recurring appointments, reminders
- Triggers & ScriptApp - Time-based and event-driven automation
Quick Start
function generateWeeklyReport() {
const ss = SpreadsheetApp.getActiveSpreadsheet();
const sheet = ss.getSheetByName('Data');
const data = sheet.getRange('A2:D').getValues();
const report = data.filter(row => row[0]);
const summarySheet = ss.getSheetByName('Summary') || ss.insertSheet('Summary');
summarySheet.clear();
summarySheet.appendRow(['Name', 'Value', 'Status']);
report.forEach(row => summarySheet.appendRow([row[0], row[1], row[2]]));
MailApp.sendEmail({
to: Session.getEffectiveUser().getEmail(),
subject: 'Weekly Report Generated',
body: `Report generated with ${report.length} records.`
});
}Best Practices
- Batch operations - read/write ranges in bulk, never cell-by-cell in loops
- Cache data - use CacheService (25 min TTL) for frequently accessed data
- Error handling - wrap operations in try/catch, log errors to a sheet for audit trails
- Respect limits - 6-minute execution timeout; split large jobs across triggers
- Minimise scopes - request only necessary OAuth permissions in
appscript.json - Persistent storage - use PropertiesService for configuration and state
- Validate inputs - always check objects exist before accessing properties
See references/best-practices.md for detailed examples of each practice.
Validation & Testing
Use the validation scripts in scripts/ for pre-deployment checks:
- scripts/validators.py - Validate spreadsheet operations, range notations, and data structures
Debug with Logger.log() and view output via View > Logs (Cmd/Ctrl + Enter). Use breakpoints in the Apps Script editor for step-through debugging.
Integration with Other Skills
- google-ads-scripts - Export Google Ads data to Sheets for reporting
- gtm-datalayer - Coordinate with GTM for tracking events triggered by Apps Script
- ga4-bigquery - Query BigQuery from Apps Script and write results to Sheets
Troubleshooting
| Issue | Solution |
|---|---|
| Execution timeout | Split work into smaller batches or use multiple triggers |
| Authorisation error | Check OAuth scopes in manifest file |
| Quota exceeded | Reduce API call frequency, use caching |
| Null reference error | Validate objects exist before accessing properties |
References
Detailed content is available in reference files (loaded on demand):
- references/apps-script-api-reference.md - Complete API reference for all built-in services, triggers, authorisation, and performance optimisation
- references/examples.md - Production-ready code examples (spreadsheet reports, Gmail auto-responder, document generation, trigger setup)
- references/best-practices.md - Detailed best practices with code blocks for batch operations, caching, error handling, scopes, and persistence
- references/patterns.md - Common reusable patterns (data validation, retry logic, form response processing)