Expense Organizer with Google Drive Routing and Gemini AI Entity Detection

Description

Who's it for

This workflow is perfect for individuals, small businesses, or households who need to:
Automatically process and categorize expense receipts
Extract structured data from invoices and receipts using AI
Store receipts in multiple locations (Google Drive and S3)
Send automated email notifications with expense details
Send documents to accounting systems via email hooks

How it works

This comprehensive expense processing workflow combines AI-powered document analysis with automated file management and notifications. Here's the complete flow:

Form Submission: Users submit expenses through a web form with receipt upload and category selection (Personal, Business, or Shared/Home)

AI Document Processing: The workflow extracts text from PDF receipts using OCR, then uses Google Gemini AI to parse and structure the data into a standardized JSON format including vendor details, amounts, dates, and categorization

Smart Routing: Based on the expense category, receipts are automatically routed to different processing paths with category-specific folder organization

Multi-Destination Storage: Receipts are uploaded to:
Google Drive (organized by year/month folders)
S3 cloud storage buckets
Different destinations based on expense type

Email Notifications: Sends formatted HTML email notifications with complete expense details and links to stored receipts

Accounting System Integration: Automatically forwards business expenses to accounting systems via email hooks (customizable per user requirements)

Requirements

Credentials needed:
Google Gemini API**: For AI-powered document analysis
Google Drive OAuth2**: For personal and business drive access
Gmail OAuth2**: For sending email notifications
S3 Storage**: For cloud backup (AWS S3, Wasabi, etc.)

Services used:
Google Drive (multiple accounts supported)
Google Gemini AI
Gmail
S3-compatible storage
Form trigger webhook

How to set up

Step 1: Configure Credentials
Set up Google Gemini API credentials in n8n
Configure Google Drive OAuth2 for both personal and business accounts
Add Gmail OAuth2 credentials
Set up S3 storage credentials

Step 2: Update Configuration
Replace all placeholder values:
YOUR_GEMINI_CREDENTIAL_ID with your Gemini credential ID
YOUR_PERSONAL_GDRIVE_CREDENTIAL_ID with personal Drive credential
YOUR_BUSINESS_GDRIVE_CREDENTIAL_ID with business Drive credential
YOUR_GMAIL_CREDENTIAL_ID with Gmail credential
YOUR_S3_CREDENTIAL_ID with S3 credential

Update Google Drive folder structure:
Replace YOUR_BUSINESS_DRIVE_ID and YOUR_SHARED_DRIVE_ID with actual drive IDs
Update the JavaScript code in the three Code nodes with your actual folder mapping

Configure email addresses:
Replace [email protected] with your notification email
Replace [email protected] with your accounting system's email hook (this is a mail hook for uploading documents to small business accounting systems - can be modified per user requirements)

Update S3 bucket names:
Replace business-expenses, personal-expenses, and shared-expenses with your bucket names

Step 3: Set Up Folder Structure
Create organized folder structures in your Google Drives:
Drive Root/
├── 2024/
│ ├── January/
│ ├── February/
│ └── ... (all months)
├── 2025/
│ ├── January/
│ └── ... (all months)
└── 2026/
└── ... (all months)

Step 4: Test the Workflow
Activate the workflow
Submit a test expense through the form
Verify files are uploaded to correct locations
Check email notifications are received

How to customize the workflow

Expense Categories
Modify the form dropdown options and conditional logic to add/remove expense categories:
Edit the "On form submission" node form fields
Update the IF condition nodes for routing
Add new processing paths as needed

AI Processing Schema
Customize the structured output parser schema to extract different fields:
Modify the JSON schema in the "Structured Output Parser" node
Update the AI system prompt for different extraction requirements
Add new fields for specific business needs

Storage Destinations
Add or modify storage locations:
Duplicate upload nodes for additional cloud services
Modify folder organization logic in Code nodes
Add new conditional routing for different storage rules

Email Templates
Customize the HTML email template:
Edit the email message content in the Gmail node
Add/remove expense fields in the table
Modify styling and branding

Folder Organization
Update the JavaScript code in Code nodes to match your folder structure:
Modify the CSV data with your actual folder IDs
Change the date-based organization logic
Add custom folder naming conventions

Integration Extensions
Extend the workflow with additional integrations:
Add Slack notifications
Connect to accounting software (QuickBooks, Xero)
Integrate with expense management platforms
Add approval workflows for business expenses