GA4 Anomaly Detection with Slack & Email Alerts

This workflow automates anomaly detection in Google Analytics 4 (GA4) data, ideal for marketing and analytics teams tracking sessions, new users, conversions, and bounce rates by channel. It fetches daily metrics via the GA4 Data API, computes 7-day rolling averages and z-scores to flag significant outliers (spikes or drops), and generates QuickChart sparklines for visual context. Anomalies trigger immediate Slack notifications per event and a single daily email consolidating all alerts into an HTML table with charts.

Key features include customizable thresholds via an ALERT_ME toggle, per-channel analysis (e.g., sessionDefaultChannelGroup), and efficient consolidation to avoid notification overload. The Code node handles sophisticated stats logic, making it robust for production use without manual intervention.

Benefits: Saves hours of daily manual checks, enables rapid response to issues like campaign failures or traffic surges, and scales across multiple GA4 properties. Use cases: E-commerce monitoring conversion drops, content sites watching organic traffic anomalies, or agencies alerting clients on paid channel performance.

Setup requires GA4 OAuth2 credentials, GA4 Property ID (numeric, not G- or UA- IDs), Slack bot token (chat:write), and email SMTP. Run on a schedule (e.g., daily) for ongoing vigilance.