Automated GA4 Analytics Data Backfill to BigQuery with Telegram Alerts

Description

This workflow automates the daily backfill of Google Analytics 4 (GA4) data into BigQuery. It fetches 13 essential pre-processed reports (including User Acquisition, Traffic, and E-commerce) and uploads them to automatically created tables in BigQuery, and then send an alert in telegram.

How it works
Configuration:** You define your Project ID, Dataset, and Date Range in a central "Config" node.
Parallel Fetching:** The workflow runs 13 parallel API calls to GA4 to retrieve key reports (e.g., ga4_traffic_sources, ga4_ecommerce_items).
Dynamic Tables:** It automatically checks if the target BigQuery table exists and creates it with the correct schema if it's missing.
Telegram Alerts:** After execution, it sends a summary message to Telegram indicating success or failure for the day's run.

Set up steps
Google Credentials (OAuth): This workflow uses n8n's built-in "Google OAuth2 API" credential. You do not need a Service Account key. Connect your Google account and ensure you grant scopes for Google Analytics API and BigQuery API.
Config Node: Open the "Backfill Config" node and fill in:
GA4 Property ID
Google Cloud Project ID
BigQuery Dataset ID
Telegram Setup (Optional): If you want alerts, configure the Telegram node with your Bot Token and Chat ID. If not, you can disable/remove this node.
Schedule: By default, this is set to run daily. It is recommended to use a date expression (e.g., Today - 2 Days) to allow GA4 time to process data fully before fetching.