Overview

This skill generates professional PDF invoices from structured data and templates. Create invoices with company branding, itemized lists, tax calculations, and payment details.

How to Use

• Describe what you want to accomplish
• Provide any required input data or files
• I'll execute the appropriate operations

Example prompts:

• "Generate invoices from order data"
• "Create recurring invoices"
• "Batch generate monthly invoices"
• "Customize invoice templates per client"

Domain Knowledge

Invoice Data Structure

invoice_data = {
    "invoice_number": "INV-2026-001",
    "date": "2026-01-30",
    "due_date": "2026-02-28",
    
    "from": {
        "name": "Your Company",
        "address": "123 Business St",
        "email": "billing@company.com"
    },
    
    "to": {
        "name": "Client Name",
        "address": "456 Client Ave",
        "email": "client@example.com"
    },
    
    "items": [
        {"description": "Consulting", "quantity": 10, "rate": 150.00},
        {"description": "Development", "quantity": 20, "rate": 100.00}
    ],
    
    "tax_rate": 0.08,
    "notes": "Payment due within 30 days"
}

PDF Generation with ReportLab

from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas
from reportlab.lib.units import inch
def create_invoice(data: dict, output_path: str):
    c = canvas.Canvas(output_path, pagesize=letter)
    width, height = letter
    
    # Header
    c.setFont("Helvetica-Bold", 24)
    c.drawString(1inch, height - 1inch, "INVOICE")
    
    # Invoice details
    c.setFont("Helvetica", 12)
    c.drawString(1inch, height - 1.5inch, f"Invoice #: {data['invoice_number']}")
    c.drawString(1inch, height - 1.75inch, f"Date: {data['date']}")
    
    # From/To
    y = height - 2.5inch
    c.drawString(1inch, y, f"From: {data['from']['name']}")
    c.drawString(4inch, y, f"To: {data['to']['name']}")
    
    # Items table
    y = height - 4inch
    c.setFont("Helvetica-Bold", 10)
    c.drawString(1inch, y, "Description")
    c.drawString(4inch, y, "Qty")
    c.drawString(5inch, y, "Rate")
    c.drawString(6inch, y, "Amount")
    
    c.setFont("Helvetica", 10)
    subtotal = 0
    for item in data['items']:
        y -= 0.3inch
        amount = item['quantity']  item['rate']
        subtotal += amount
        c.drawString(1inch, y, item['description'])
        c.drawString(4inch, y, str(item['quantity']))
        c.drawString(5inch, y, f"${item['rate']:.2f}")
        c.drawString(6inch, y, f"${amount:.2f}")
    
    # Totals
    tax = subtotal  data['tax_rate']
    total = subtotal + tax
    
    y -= 0.5inch
    c.drawString(5inch, y, f"Subtotal: ${subtotal:.2f}")
    y -= 0.25inch
    c.drawString(5inch, y, f"Tax ({data['tax_rate']100}%): ${tax:.2f}")
    y -= 0.25inch
    c.setFont("Helvetica-Bold", 12)
    c.drawString(5inch, y, f"Total: ${total:.2f}")
    
    c.save()
    return output_path

HTML Template Approach

from weasyprint import HTML
from jinja2 import Template
invoice_template = """



    


    

        
INVOICE
        

            
Invoice #: {{ invoice_number }}
            
Date: {{ date }}
        
    
    
        {% for item in items %}
        
        {% endfor %}
    

        
Description
Qty
Rate
Amount

            
{{ item.description }}
            
{{ item.quantity }}
            
${{ "%.2f"|format(item.rate) }}
            
${{ "%.2f"|format(item.quantity  item.rate) }}
        
    
Total: ${{ "%.2f"|format(total) }}


"""
def create_invoice_html(data: dict, output_path: str):
    template = Template(invoice_template)
    
    # Calculate total
    total = sum(i['quantity']  i['rate'] for i in data['items'])
    total = (1 + data.get('tax_rate', 0))
    data['total'] = total
    
    html = template.render(data)
    HTML(string=html).write_pdf(output_path)
    return output_path

Best Practices

• Validate required fields before generation
• Use templates for consistent branding
• Auto-calculate totals (don't trust input)
• Include payment instructions and terms*

Installation

# Install required dependencies
pip install python-docx openpyxl python-pptx reportlab jinja2

Resources

• easy-invoice-pdf Repository
• Claude Office Skills Hub