Weekly Active Users: Week-over-Week Alert

What This Does

Every Monday at 11 AM, this workflow:

1. Queries Mixpanel for weekly active users, broken down by account

2. Compares this week vs. last week for every account

3. Logs all results to a Google Sheet (running history)

4. Filters for significant changes — any account with >10% swing (up or down)

5. Emails your team a formatted alert showing exactly which accounts moved and by how much

6. Cleans up temporary sheet columns after 24 hours

Flow

Monday 11 AM → Calculate Date Range → Fetch WAU from Mixpanel
  → Parse & Compare WoW → Log to Google Sheet → Filter >10% Changes
  → Build HTML Email → Send to Team → Wait 24h → Clean Up Sheet

Prerequisites

• n8n (self-hosted or Cloud)
• Mixpanel account with a saved Insights report showing WAU broken down by account
• Google Sheets — a blank sheet for logging
• Gmail — OAuth2 connected account for sending alerts

Setup (15 minutes)

Step 1: Import the Workflow

Open n8n → Workflows → Import from File → upload workflow.json.

Step 2: Configure Mixpanel

1. Create an HTTP Basic Auth credential:

- Go to n8n Credentials → Add Credential → HTTP Basic Auth

- User: Your Mixpanel Service Account username

- Password: Your Service Account secret

- Find these in Mixpanel → Organization Settings → Service Accounts

2. Update the Fetch WAU Data node:

- Replace YOUR_PROJECT_ID with your Mixpanel project ID (found in Mixpanel → Project Settings)

- Replace YOUR_BOOKMARK_ID with your saved Insights report ID (from the URL when viewing the report: mixpanel.com/project/XXXXX/view/XXXXX/app/boards#id=BOOKMARK_ID)

3. Update the Process Mixpanel Data code node:

- Change SERIES_KEY to match your Mixpanel event name (line 3)

- Default is 'WAU of Session Start' — replace with whatever your event is called

Step 3: Set Up Google Sheets

1. Create a new Google Spreadsheet

2. Add these column headers in row 1: Acc.Id, Acc.Subdomain (the remaining date columns are auto-generated)

3. In n8n, go to Credentials → Add Credential → Google Sheets OAuth2

4. Replace YOUR_GOOGLE_SHEET_URL in both Google Sheets nodes:

- Log to Google Sheet node

- Clean Up Temp Columns node

Step 4: Configure Email

Open the Send Alert Email node and replace the sendTo field with your team's email addresses, comma-separated:

cs-lead@yourcompany.com, cs-ops@yourcompany.com

Connect your Gmail OAuth2 credential.

Step 5: Activate

Toggle the workflow to Active. It will run every Monday at 11 AM.

Customization

Change the Alert Threshold

Open the Filter Significant Changes code node and change the THRESHOLD variable:

const THRESHOLD = 10; // percent — change this

• 5 → More alerts (catches smaller usage dips)
• 20 → Fewer alerts (only flags major swings)
• Consider using different thresholds for drops vs. growth by modifying the filter logic

Change the Schedule

Open the Every Monday 11 AM trigger node to adjust:

• triggerAtDay → Day of week (0=Sun, 1=Mon, ..., 6=Sat)
• triggerAtHour → Hour in your n8n instance timezone

Track Different Metrics

This workflow uses Mixpanel's Insights API with a saved report (bookmark). You can:

• Create different Mixpanel reports (DAU, feature usage, session count)
• Point the HTTP Request node to a different bookmark_id
• Adjust the SERIES_KEY in the code node to match the new event name

Add Slack Alerts

To also post to Slack, add a Slack node after Build Alert Email and connect it in parallel with the Gmail node. Use the $json.html field (strip HTML tags) or build a separate Slack Block Kit message.

Troubleshooting

Problem

Fix

Empty email / no data	Check that your Mixpanel report has data for last week. Verify project_id and bookmark_id are correct.
Auth error on Mixpanel	Service Account credentials may have expired. Regenerate in Mixpanel → Service Accounts.
Google Sheets "permission denied"	Re-authorize the Google Sheets OAuth2 credential. Make sure the sheet is owned by or shared with the connected Google account.
All accounts filtered out	Lower the THRESHOLD in the filter node — your accounts may have <10% changes.
Dates look wrong	The date calculation assumes your n8n instance timezone. Check Settings → Timezone in your n8n instance.