🧾 AI Invoice Generator Agent

This project is an AI-powered invoice assistant that:

• Reads invoice data from a CSV or a user-supplied list.
• Generates a professional, styled invoice in PDF format.
• Dynamically applies tax, logo, due dates, and currency formatting.
• Supports multi-page rendering, with a "Balance Due" box on page 1.

Built using LlamaIndex, fpdf, and OpenAI’s gpt-4o-mini.

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🚀 Features

✅ Reads invoice entries from a CSV
✅ Accepts direct list entries (e.g. 'Wed, Apr 2 : 4.4 : 50')
✅ Supports custom company logo and invoice layout
✅ Adds tax, due date, and invoice number
✅ Multi-currency support (₦, US$, €, £, ¥)
✅ Prevents runaway loops with tool-agent architecture

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📦 Dependencies

Install requirements with:

pip install fpdf python-dotenv llama-index nest_asyncio openai

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🧠 Agent Tools

Tool Name	Description
read_invoice(file_path)	Parses a CSV and returns invoice entries
generate_invoice_pdf_with_reference(...)	Generates styled PDF from entries

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🏗️ Usage

1. Setup

Create a .env file with your OpenAI key:

OPENAI_API_KEY=sk-...

Your CSV file must be formatted with at least:

Date, Description, Quantity, Price
04/01/2025, Task, 4.4, 50

2. Run the Agent

Edit and run the async block:

response = await agent.run("""
Use data from data/april_2025.csv and format the invoice using the layout in invoice_sample_layout.png.

Also:
- Use data/company_logo.png as the company logo.
- Apply a tax of 0% to the total cost.
- Due date is 5 days from today.
- Generate the invoice number starting with INV_ followed by a random 6-digit number.
- Use the following entries instead of the CSV:
[
  'Printer Ink Cartridge : 4.4 : 67',
  'Wireless Mouse : 5.0 : 42',
  'Desk Organizer : 5.3 : 88',
  'Ergonomic Chair : 1.5 : 115',
  'Whiteboard Markers : 1.1 : 34',
  'Sticky Notes : 2.6 : 22',
  'Laptop Stand : 2.7 : 95',
  'Filing Cabinet : 6.5 : 103',
  'Monitor Riser : 2.1 : 39',
  'Conference Speaker : 2.5 : 78',
  'Keyboard Tray : 2.7 : 65',
  'Surge Protector : 5.7 : 49',
  'USB-C Hub : 2.1 : 59',
  'Paper Shredder : 7.2 : 102',
  'Portable Scanner : 4.9 : 74',
  'Desk Lamp : 2.0 : 56',
  'Office Chair Mat : 7.4 : 81',
  'Document Tray : 3.6 : 33',
  'Wireless Keyboard : 4.8 : 60',
  'Notebook Pack : 4.9 : 19'
]
- Generate the invoice in `ngn` currency.
""")

3. Output

You will get a response like:

{
  "pdf_path": "styled_invoice.pdf",
  "total_cost": 3950.0,
  "invoice_number": "INV_348210",
  "status": "Invoice generated successfully."
}

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🌍 Supported Currencies

Code	Symbol
usd	US$
eur	€
gbp	£
ngn	₦
jpy	¥

To use, simply pass currency="eur" in the prompt.

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🧠 Architecture

Powered by:

• 🧠 FunctionAgent from LlamaIndex
• 🛠️ FunctionTool wrappers
• 📄 fpdf for PDF rendering
• 🔁 Controlled with max_iterations=2 to avoid infinite tool loops

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📂 Folder Structure

.
├── data/
│   ├── april_2025.csv
│   ├── company_logo.png
│   └── invoice_sample_layout.png
├── invoice_debug.log
├── styled_invoice.pdf
└── main.py

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📄 License

MIT — use it commercially or for learning!
Credit appreciated: Temitope Olotin