Track and analyze Google Sheets expenses with Gemini and Gmail alerts

Description

Expense Leak Detector
Smart Expense Monitoring in Minutes

This n8n workflow reads your expenses from Google Sheets, categorizes them using predefined keywords, summarizes spending per category, generates AI-powered financial advice using Gemini, stores results in another sheet and sends email alerts for high or normal expenses.

Quick Start Guide

Import the workflow into n8n

Connect:
Google Sheets OAuth2
Google Gemini API
Gmail OAuth2

Update the Settings node:
Budget limit
Recipient email
Sender name

Ensure:
Sheet1 → Date, Description, Amount
Sheet2 → Date, Category, Total Spent, AI Report, Status, Reviewed On

Click "Execute Workflow"

What It Does

This workflow automates your expense tracking and financial analysis using a combination of Google Sheets and AI.

It begins by fetching raw expense data from a Google Sheet (Sheet1), where each row contains a date, description and amount. The workflow then processes each row by cleaning the data and assigning a category such as Food, Transport, Subscription, Shopping, Utilities, Health or Other using predefined keyword matching.

Once categorized, it aggregates total spending per category and evaluates whether the spending exceeds a defined budget limit. Based on this evaluation, it generates a detailed, personalized financial advisory report using Google Gemini AI.

Finally, the workflow stores all results in another sheet (Sheet2) and sends an email notification—either a high expense alert or a normal summary—based on the spending status.

Who’s It For

Individuals managing personal finances
Freelancers tracking monthly expenses
Families monitoring household spending
Finance enthusiasts wanting AI-driven insights
Anyone using Google Sheets for expense tracking

Requirements

To use this workflow, you need:

n8n (self-hosted or cloud)
Google Sheets account
Google Gemini API key
Gmail account (for sending emails)
A Google Sheet with:
Sheet1: Expense data
Sheet2: Output report

How To Set Up

1. Import Workflow

Import the provided JSON file into n8n

2. Connect Credentials

Google Sheets OAuth2** → For reading and writing data
Google Gemini API** → For AI report generation
Gmail OAuth2** → For sending emails

3. Prepare Google Sheets

Sheet1 (Input)

| Date | Description | Amount |
|------|------------|--------|

Sheet2 (Output)

| Date | Category | Total Spent | AI Report | Status | Reviewed On |
|------|------------|--------|------|------------|--------|

4. Configure Settings Node

Update the “Settings — Change These Before Running” node:

Budget Limit → Threshold for high expense detection
Send Report To Email → Recipient email
Email Sender Name → Display name
Currency Symbol → Example: Rs.
Report Period → Example: This Month

5. Run Workflow

Click “Execute Workflow”
The workflow will:
Read expenses
Categorize them
Generate AI insights
Save results
Send email alerts

How It Works (Step-by-Step Flow)

Manual Trigger
Starts the workflow

Read Expenses
Fetches rows from Sheet1

Settings Node
Stores all configurable values

Clean & Categorize
Converts description to lowercase
Assigns categories using hardcoded keyword logic

Summarize
Groups data by category
Calculates total spend

Build AI Fields
Prepares structured input for Gemini

Gemini AI
Generates detailed financial advisory report

Collect Data
Formats data for storage and email

Save to Sheet2
Appends results

Condition Check
Determines if expense is high or normal

Email Notifications
Sends:
High Expense Alert OR
Normal Summary

How To Customize Nodes

1. Categorization Logic

Modify the “Clean and Categorise Each Expense Row” node
Add or update keyword checks for categories

2. Budget Threshold

Change Budget Limit in Settings node

3. AI Prompt
Edit “Ask Gemini to Write Expense Report”
Customize tone, format or advice style

4. Email Content

Modify:
Subject lines
Email body
Sender name

5. Currency & Region

Update:
Currency symbol
Date format (if needed)

Add-Ons (Enhancements)

Add Cron Trigger for automatic daily/monthly runs
Integrate Slack/WhatsApp alerts
Add dashboard visualization (Google Data Studio / Looker)
Store reports in Notion or Airtable
Add multi-user expense tracking
Enable PDF report generation

Use Case Examples

Monthly Personal Expense Review
Automatically analyze and summarize monthly spending

High Spending Alerts
Get notified when a category exceeds your budget

Subscription Cost Optimization
Identify unnecessary recurring expenses

Family Budget Monitoring
Track combined household expenses

Freelancer Expense Tracking
Monitor business vs personal expenses

There can be many more variations of this workflow depending on your needs.

Troubleshooting Guide

| Issue | Possible Cause | Solution |
|------|--------------|---------|
| No data fetched | Incorrect Sheet ID or tab | Verify Sheet1 configuration |
| Categories not accurate | Keyword mismatch | Update categorization logic |
| AI report not generated | Invalid Gemini API key | Reconnect API credentials |
| Emails not sent | Gmail not connected | Reauthorize Gmail OAuth |
| Sheet2 not updating | Column mismatch | Ensure correct headers |
| Always "Normal Expense" | Budget too high | Adjust Budget Limit |
| Missing email recipient | Email not set in Settings | Add recipient email |

Need Help?

If you need help setting up, customizing or extending this workflow, we’re here to support you.

Whether you want:
Advanced automation
Custom AI workflows
Business process optimization
Integration with your existing systems

Reach out to WeblineIndia for expert assistance in building powerful, scalable automation solutions tailored to your needs.