Alert on GA4 anomalies from Google Analytics to Slack and email

## Who’s it for

Teams that monitor traffic, signups, or conversions in Google Analytics 4 and want automatic Slack/email alerts when a channel suddenly spikes or drops.

## What it does

This n8n template pulls daily GA4 metrics, detects outliers with a rolling mean and z-score, and sends alerts with a sparkline chart. It supports per-channel analysis (e.g., sessionDefaultChannelGroup) and consolidates multiple anomalies into a single email while posting each one to Slack.

## How it works

* **HTTP Request (GA4 Data API)** fetches sessions, newUsers, conversions, bounceRate by date + channel.

* **Code** calculates 7-day moving average and z-scores, flags anomalies, and builds QuickChart links.

* **If** filters on alert === true and optional ALERT_ME toggle.

* **Slack** posts an alert + chart.

* **Email** sends one summary email (subject + HTML table + charts).

## Requirements

* GA4 OAuth2 credential in n8n.

* Slack API credential (bot with chat\:write).

* Email credential (SMTP or service).

* GA4 property ID and at least several recent days of data.

## Where to find your GA4 Property ID

* **In the GA UI:**

1. Open **Google Analytics** → bottom-left **Admin** (gear).

2. In the **Property** column, click **Property settings**.

3. Copy **Property ID** — it’s a **numeric** value (e.g., 481356553).

* **From the URL (quick way):**

When you’re inside the GA4 property, the URL looks like:

…/analytics/web/#/p123456789/… → the digits after **`p`** are your **Property ID** (`123456789` in this example).

* **What not to use:**

* **Measurement ID** (looks like G-XXXXXXX) — that’s the data stream ID, **not** the property ID.

* **Universal Analytics IDs** (`UA-XXXXX-Y`) — those are legacy and won’t work with GA4 Data API.

* **In this template:**

Put that numeric ID into the **Set → PROPERTY_ID** field. The HTTP node path properties/{{ $json.PROPERTY_ID }}:runReport expects **only the number**, no prefixes.

## How to set up

1. Open the **Set (Define variables)** node and fill: PROPERTY_ID, LOOKBACK_DAYS, ALERT_PCT, Z_THRESHOLD, CHANNEL_DIM, ALERT_ME.

2. Connect your **Google Analytics OAuth2**, **Slack**, and **Email** credentials.

3. In **Email Send**, map Subject → {{$json.emailSubject}} and **HTML** body → {{$json.emailHtml}}. Keep **Execute once** enabled.

4. Run the workflow.

## How to customize

* Change the moving-average window (`WINDOW/MA_WINDOW`) and chart range (`LAST_N_DAYS_CHART`).

* Swap CHANNEL_DIM (e.g., source/medium) to analyze different dimensions.

* Add/remove metrics in the GA4 request and the metrics list in the Code node.

* Tweak thresholds to reduce noise: raise Z_THRESHOLD or ALERT_PCT.

## Output Example