AutoInvoice AI – Agentic Invoice Generator & Sender

AutoInvoice AI is an agentic automation tool built with AI to generate, customize, and send invoices automatically — in just ~35 seconds per client. It pulls data from forms, Google Sheets, or Excel files, creates PDF invoices, and emails them directly to clients.

Ideal for marketing agencies, e-commerce, SaaS, and software houses looking to save hours on manual billing.

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✨ Features

• 🧠 AI-Powered Automation: Uses OpenAI Agents SDK with GPT-4o-mini and 3 specialized agents (Validation → Template → Delivery) for end-to-end invoice processing
• 📊 Multiple Data Sources: Input via web form, Google Sheets, or Excel upload
• 🧾 PDF Generation: Creates styled invoices using Jinja2 templates and pdfkit
• 📧 Email Delivery: Sends invoices via Gmail SMTP with attachments
• ⚙️ Scalable MVP: Handles 2–5 clients in demo mode (~35 sec/invoice)
• 🖥️ Real-Time Progress: Streamlit UI shows live status — Fetching → Generating → Sending
• 📦 Download Options: Download individual PDFs or all invoices as a ZIP
• 🛡️ Robust Error Handling: Graceful fallbacks for template loading, JSON parsing, and email sending

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🧰 Tech Stack

Layer	Technology
Backend	FastAPI, OpenAI Agents SDK, Python 3.12+
Frontend	Streamlit
AI Model	OpenAI GPT-4o-mini via OpenAI Agents SDK
Templates	Jinja2
PDF Generation	pdfkit + wkhtmltopdf
Email	smtplib (Gmail SMTP + MIME)
Data Processing	Pandas, Requests
Automation Workflow	n8n

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⚙️ Installation

Prerequisites

• Python 3.12+
• Git
• Gmail account with App Password (for email sending)

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1. Clone the Repository

git clone https://github.com/Shahzain-Ali/agentic-invoice-generator.git
cd agentic-invoice-generator

2. Install Dependencies

uv sync

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3. Setup wkhtmltopdf (for PDF Generation)

wkhtmltopdf converts HTML to PDF. Required by pdfkit.

Windows

1. Download from wkhtmltopdf.org/downloads.html
   • Select: Windows (MSVC 2015) → wkhtmltox-0.12.6-1.msvc2015-win64.exe
2. Run the .exe as Administrator
3. Tick "Modify PATH" → Install
4. Verify installation:

   wkhtmltopdf --version

macOS

1. Install via Homebrew:

   brew install wkhtmltopdf

2. Verify installation:

   wkhtmltopdf --version

Don't have Homebrew? Install it first:

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

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4. Environment Setup

1. Copy the example environment file:

   cp .env.example .env

2. Open .env and fill in your actual values:

   OPENAI_API_KEY=your_openai_api_key
   GMAIL_EMAIL=your_email@gmail.com
   GMAIL_APP_PASSWORD=your_16_digit_app_password
   GOOGLE_SHEET_ID=your_google_sheet_id
   GOOGLE_CREDENTIALS_PATH=credentials.json
   WKHTMLTOPDF_PATH=C:\Program Files\wkhtmltopdf\bin\wkhtmltopdf.exe
   API_URL=http://localhost:8000
   

How to get Gmail App Password: Google Account → Security → 2-Step Verification → App Passwords → Generate

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🚦 Usage

Run Backend (FastAPI)

uvicorn backend.api.main:app --reload --port 8000

Run Frontend (Streamlit)

streamlit run frontend/userInterface.py

In the Streamlit UI

1. Fill the form or connect to Google Sheets or upload an Excel file
2. Click "Process & Deliver Invoices"
3. Watch live progress (Fetching → Generating → Sending)
4. Download PDFs individually or all invoices as a ZIP

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📺 Demo

Project Demo Video (Coming Soon) — Coming Soon

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📜 License

This project is licensed under the MIT License. © 2025 Shahzain Ali

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💬 Connect

• 💻 GitHub: Shahzain Ali
• 📧 Email: alishahzain604@gmail.com