Track Expenses via Multimodal Telegram Inputs with Gemini AI and Google Sheets

Created by

Cuong Nguyen

Last update

Last update 11 hours ago

Why I built this? (The Problem)

Most expense tracker apps (like Money Lover, Spendee, or Wallet) have a common friction point: Data Entry. You have to unlock your phone, find the app, wait for it to load, navigate menus, and manually select categories. It’s tedious, so we often forget to log small expenses.

I wanted a solution that lives where I already spend my time: Telegram. This workflow allows you to log expenses in seconds—just by sending a text, a voice note while driving, or a photo of a receipt. No UI navigation required.

Comparison: This Workflow vs. Traditional Apps

Feature	Traditional Expense Apps	This n8n Workflow
Data Ownership	Data is locked in their proprietary database.	100% Yours. It lives in your Google Sheet. You can export, pivot, or connect it to Looker Studio.
Input Speed	Slow. Requires multiple taps/clicks.	Instant. Send a text/voice/photo to a Telegram bot.
Flexibility	Rigid categories & logic.	Infinite. You can customize the AI prompt, categories, and currency logic.
Cost	Often requires monthly subscriptions for premium features.	Low Cost. Runs on your n8n instance + Gemini Flash API (which is currently free/very cheap).
UI/UX	Beautiful, pre-built mobile dashboards.	Raw Data. You view data in Google Sheets (though you can build a dashboard there)

Key Features

Multi-Modal Input: Just send what you have.
-- Text: "Lunch 50k, Taxi 30k" (Splits into 2 rows).
-- Voice: Speak naturally, AI transcribes and extracts data.
-- Photo: OCRs receipts and parses details.
Global Currency Support: Uses Gemini AI to intelligently detect currency. You can set a default currency (e.g., USD, VND) in the Config node.
Smart Extraction & Categorization:
-- Automatically splits multiple items in one message (e.g., "Lunch 20k and Grab 50k" → 2 separate rows).
-- AI automatically assigns categories (Food, Transport, Bills, etc.) based on the item name.
Budget Management: Use the command /add budget 500 to instantly top up your monthly budget.
"Quiet" Reporting: Instead of spamming you after every message, the system waits for 30 minutes of inactivity before sending a daily summary report (Debounce logic).

Setup Instructions

1. Prerequisites

Google Sheet: You MUST make a copy of this template: [Google Sheet Template here]
n8n Data Table: This workflow requires a Data Table named ReportTokens for the reporting feature. Please read the setup guide below. Setup Guide: AI Expense Tracker

2. Configure the Workflow

Credentials: Connect Telegram, Google Sheets, and Google Gemini (PaLM).
Config Node: Open the CONFIG - User Settings node and update these fields.

-- spreadsheet_id: The ID of your copied Google Sheet
-- sheet_gid_dashboard: The ID of your sheet Dashboard
-- sheet_gid_budget: he ID of your sheet Budget_Topups
-- currency_code: Your currency code (e.g., USD, EUR, VND).
-- currency_symbol: Your currency symbol (e.g., $, €, ₫).
-- locale: Your locale for number formatting (e.g., en-US, vi-VN).
Data Table: Create a table in n8n with columns: chat_id, report_token, updated_at (All type: String). Link this table to the relevant nodes in the workflow.

3. Usage

Log Expense: Send "Coffee $5" or a photo.
Add Budget: Send command /add budget 1000

Need Help or Want to Customize This?

Contact me for consulting and support:
Email: [email protected]