Invoice Generation Skill

Overview

Generate professional HTML invoices using pre-configured templates for hourly and subscription billing. Track client information, automatically increment invoice numbers, and maintain invoice history across all clients.

When to Use This Skill

Use this skill when:

• •Creating a new invoice for an existing client by name
• •Adding a new client to the invoice system
• •Viewing client information or invoice history
• •Generating invoices with work log entries (hourly) or subscription billing

Core Capabilities

1. Generate Invoice for Existing Client

When the user requests an invoice for a client by name:

1. •

   Load client data from clients.json to retrieve:

   • •Client details and billing information
   • •Invoice type (hourly or subscription)
   • •Last invoice number for auto-increment
2. •

   For hourly invoices:

   • •Request work log entries from the user (they will paste as text)
   • •Parse work log format: Date - Project - Hours - Description
   • •For Versa Computing, parse: Date - Project - Hours - Description with separate Project and Description columns
   • •Calculate total hours and amount (hours × hourly_rate)
3. •

   For subscription invoices:

   • •No work log needed
   • •Use subscription_name and subscription_amount from client data
4. •

   Increment invoice number:

   • •New number = last_invoice_number + 1
   • •Format: {invoice_prefix}-2025-{new_number:03d}
5. •

   Calculate dates:

   • •Invoice date: Use current date (check system date in environment)
   • •Due date: Invoice date + payment_terms_days
6. •

   Load appropriate template:

   • •Hourly: assets/hourly-invoice-template.html
   • •Subscription: assets/subscription-invoice-template.html
7. •

   Replace placeholders with client data:

   • •{{INVOICE_NUMBER}}, {{INVOICE_DATE}}, {{DUE_DATE}}
   • •{{CLIENT_NAME}}, {{CLIENT_ATTENTION}}, {{CLIENT_ADDRESS_LINE1}}, {{CLIENT_CITY_STATE_ZIP}}
   • •{{PAYMENT_TERMS}} (e.g., "30" for Net 30)
   • •{{PROJECT_REFERENCE}} or {{PO_NUMBER}} as applicable
   • •For hourly: {{TOTAL_HOURS}}, {{HOURLY_RATE}}, {{SUBTOTAL}}, {{TOTAL_AMOUNT}}
   • •For subscription: {{SUBSCRIPTION_NAME}}, {{BILLING_MONTH}}, {{AMOUNT}}
   • •Work log entries (populate table rows in HTML)
8. •

   Special handling for Versa Computing:

   • •Use 4-column work log table: DATE | PROJECT | DESCRIPTION | HOURS
   • •Separate project name from description in work log entries
   • •Project names go in the PROJECT column, descriptions in DESCRIPTION column
9. •

   Save invoice:

   • •Filename format: Invoice-{invoice_number}-{short_name}-{month}-2025.html
   • •Location: User's Desktop (/Users/arlenagreer/Desktop/)
10. •

    Update clients.json:

    • •Set last_invoice_number to new number
    • •Set last_invoice_date to invoice date
    • •Save changes to maintain accurate history

2. Add New Client

To add a new client to the system:

1. •

   Request necessary information:

   • •Company name and contact details (attention, address)
   • •Invoice type (hourly or subscription)
   • •Invoice number prefix (3-letter abbreviation)
   • •Billing rate (for hourly) or subscription amount
   • •Payment terms in days
   • •Special requirements (e.g., project column, PO number)
2. •

   Add new client object to clients.json following the existing structure

3. •

   Confirm client has been added successfully

3. View Client Information

To view or list clients:

• •Read clients.json and display client details
• •Show invoice history (last invoice number and date)
• •List all tracked clients

Client Database Structure

Client information is stored in clients.json in the skill folder. Each client entry includes:

Required fields (all clients):

• •name: Full client name
• •short_name: Abbreviated name for filenames
• •invoice_prefix: 3-letter invoice number prefix
• •invoice_type: "hourly" or "subscription"
• •company_name: Company name for invoice
• •attention: Contact attention line
• •address_line1: Street address
• •city_state_zip: City, state, and ZIP
• •last_invoice_number: Last invoice number sent (integer)
• •last_invoice_date: Date of last invoice (YYYY-MM-DD)
• •payment_terms_days: Payment terms in days (e.g., 30 for Net 30)

Hourly invoice fields:

• •hourly_rate: Billing rate per hour
• •project_reference: Default project name
• •requires_project_column: (optional) true if work log needs separate project column

Subscription invoice fields:

• •subscription_name: Name of subscription service
• •subscription_amount: Monthly subscription amount

Current Clients

• •American Laboratory Trading (INV prefix, hourly billing)
• •Empirico (EMP prefix, subscription billing)
• •Versa Computing (VER prefix, hourly billing with project column)

Invoice Templates

Hourly Invoice Template

Located at: assets/hourly-invoice-template.html

Features:

• •Two-page layout: invoice summary (page 1) and detailed work log (page 2)
• •Standard work log table: DATE | HOURS | DESCRIPTION
• •For clients requiring project column: DATE | PROJECT | DESCRIPTION | HOURS
• •Professional styling with Inter font and blue color scheme (#2563eb)
• •Print-optimized CSS

Placeholders to replace:

• •{{INVOICE_NUMBER}}, {{INVOICE_DATE}}, {{DUE_DATE}}
• •{{CLIENT_NAME}}, {{CLIENT_ATTENTION}}, {{CLIENT_ADDRESS_LINE1}}, {{CLIENT_CITY_STATE_ZIP}}
• •{{PAYMENT_TERMS}}, {{PROJECT_REFERENCE}}, {{PO_NUMBER}}
• •{{TOTAL_HOURS}}, {{HOURLY_RATE}}, {{SUBTOTAL}}, {{TOTAL_AMOUNT}}
• •Work log table rows (HTML tbody content)

Subscription Invoice Template

Located at: assets/subscription-invoice-template.html

Features:

• •Single-page layout
• •Simplified line items table: Description and Amount only
• •Same professional styling as hourly template

Placeholders to replace:

• •{{INVOICE_NUMBER}}, {{INVOICE_DATE}}, {{DUE_DATE}}
• •{{CLIENT_NAME}}, {{CLIENT_ATTENTION}}, {{CLIENT_ADDRESS_LINE1}}, {{CLIENT_CITY_STATE_ZIP}}
• •{{PAYMENT_TERMS}}, {{SUBSCRIPTION_NAME}}, {{PO_NUMBER}}
• •{{BILLING_MONTH}}, {{AMOUNT}}

Workflow Example

User: "Generate an invoice for Versa Computing"

Process:

1. •Read clients.json and locate Versa Computing client data
2. •Determine invoice type: hourly (requires work log)
3. •Prompt: "Please provide the work log entries for this invoice"
4. •User pastes work log text
5. •Parse entries, extracting: date, project, description, hours
6. •Calculate totals: sum hours × hourly_rate
7. •Increment invoice number: VER-2025-011 → VER-2025-012
8. •Calculate dates: invoice_date (today), due_date (today + 30 days)
9. •Load assets/hourly-invoice-template.html
10. •For Versa, use 4-column work log table format
11. •Replace all placeholders with client data and formatted work log entries
12. •Save to: /Users/arlenagreer/Desktop/Invoice-VER-2025-012-VersaComputing-Nov-2025.html
13. •Update clients.json: set last_invoice_number to 12, last_invoice_date to today
14. •Confirm: "Invoice VER-2025-012 generated and saved to Desktop. Ready for review."

Important Notes

• •Date handling: Always check the system date in <env> context (Today's date)
• •Work log parsing: Accept pasted text format, parse carefully to extract all components
• •Decimal hours: Use decimal format (0.5, 1.0, 2.5) not time format
• •Invoice numbering: Always auto-increment based on last_invoice_number
• •File location: Save all invoices to /Users/arlenagreer/Desktop/
• •No email sending: Skill only generates HTML files; user reviews and sends manually
• •Database updates: Always update clients.json after successful invoice generation
• •Template format: For Versa, modify table structure to include PROJECT column between DATE and DESCRIPTION