Agentic Invoice Skill

Create tailored invoices, invoice line items, payment requests, credit memos, pro forma invoices, recurring invoices, milestone invoices, change-order invoices, expense pass-through invoices, late-fee notices, and end-to-end billing workflows for agentic development services. Use when Codex needs to choose, draft, validate, or adapt invoice documents for agentic software workflow engagements from deposit through final payment and post-sale support.

Purpose

Create practical invoice documents for agentic development services end to end: upfront deposits, scoped pilots, discovery, implementation, evaluation, change orders, retainers, support, expenses, credits, late fees, refunds, and closeout.

System Boundary

This skill owns billing document drafting and invoice-event selection. Use agentic-proposal-skill for pricing rationale or commercial scope before approval, agentic-contract-skill for agreement terms, agentic-delivery-skill for milestone evidence, agentic-email-skill for the message that sends an invoice, and an accounting system or human reviewer for final tax, payment, ledger, and collection decisions.

Core Workflow

1. Identify the invoice event: estimate, deposit, milestone, monthly retainer, time and materials, change order, expense, final invoice, credit, late fee, refund, or renewal.
2. Gather required facts: provider, client, invoice number, issue date, due date, terms, currency, contract or SOW reference, project name, billing period, line items, taxes, discounts, credits, previous payments, payment instructions, and notes.
3. Use references/invoice-positioning.md for service language and risk boundaries.
4. Use references/use-case-decision-table.md to choose the right invoice type.
5. Use references/invoice-lifecycle.md for end-to-end billing flow and gates.
6. Use references/invoice-catalog.md for the near-exhaustive invoice template library.
7. Draft clearly and conservatively. Do not invent tax IDs, banking details, tax rates, contract terms, or legal/accounting claims.

Invoice Selection Guide

Choose by billing event:

• Before signed agreement or purchase order: use pro-forma-invoice or deposit-request-invoice.
• Fixed-scope pilot deposit: use pilot-deposit-invoice.
• Workflow assessment only: use discovery-assessment-invoice.
• Contract signing deposit: use contract-deposit-invoice.
• Milestone reached: use milestone-invoice.
• Prototype delivered: use prototype-delivery-invoice.
• Evaluation or test-set work delivered: use evaluation-work-invoice.
• Documentation and handoff complete: use handoff-invoice.
• Final balance due: use final-balance-invoice.
• Hourly work: use time-and-materials-invoice.
• Monthly support or managed monitoring: use monthly-retainer-invoice.
• Recurring agent operations support: use recurring-support-invoice.
• Additional scope after agreement: use change-order-invoice.
• Rush work: use rush-fee-invoice.
• Added integration or tool connector: use integration-add-on-invoice.
• API, model, hosting, storage, or third-party pass-through charges: use usage-pass-through-invoice.
• Travel, printing, procurement, or reimbursable costs: use expense-reimbursement-invoice.
• Support hours exceeded: use support-overage-invoice.
• Late payment fee or finance charge: use late-fee-invoice.
• Payment plan installment: use installment-invoice.
• Partial payment received: use partial-payment-receipt-invoice.
• Client prepayment or credit balance: use prepayment-credit-invoice.
• Discount or courtesy reduction: use discount-adjustment-invoice.
• Correcting a prior invoice: use corrected-invoice.
• Cancelled project with earned work: use termination-invoice.
• Refund owed: use refund-memo.
• Credit owed against future work: use credit-memo.
• Retainer renewal: use retainer-renewal-invoice.
• Expansion to a second workflow: use expansion-workflow-invoice.
• Training or enablement: use training-invoice.
• Advisory-only work: use advisory-invoice.
• Acceptance holdback release: use holdback-release-invoice.
• Tax-only adjustment: use tax-only-invoice.
• Voiding a prior invoice: use voided-invoice-notice.
• Confirming full payment: use paid-in-full-receipt.

When several templates fit, choose the invoice closest to the actual commercial trigger. For example, if a prototype was delivered but the contract bills only on milestone acceptance, use milestone-invoice, not prototype-delivery-invoice.

Quality Rules

• Use exact client-provided amounts and terms.
• Keep line items specific enough for approval but not cluttered.
• Tie invoices to contract, SOW, change order, or accepted milestone references when available.
• Separate professional services, third-party pass-throughs, expenses, taxes, credits, and late fees.
• Mark drafts as drafts if payment details or tax handling are unknown.
• Do not put legal, tax, or accounting advice on invoices unless the user specifically asks for explanatory notes.
• Never fabricate bank accounts, tax IDs, purchase order numbers, tax rates, or compliance status.

Resource Guide

• references/invoice-positioning.md: load for agentic development service wording, line-item language, and boundaries.
• references/use-case-decision-table.md: load when choosing which invoice to use.
• references/invoice-lifecycle.md: load for end-to-end invoicing workflows, approval gates, and follow-up steps.
• references/invoice-catalog.md: load for the near-exhaustive invoice template library.
• references/template-index.json: machine-readable template metadata used by the renderer.
• scripts/render_invoice.py: list invoice templates or render a draft with placeholders.

Runtime Permissions

This skill is a local document-rendering workflow. It reads bundled templates, references, examples, assets/logo.png, and user-provided Markdown or invoice variables. It writes only the user-selected --out, --png, --markdown-out, or default output/ artifact paths. It runs local Python entry points for scripts/render_invoice.py and scripts/render_pdf.py.

It does not require network access, credential access, persistence, privilege escalation, destructive file operations, or background services.

Renderer

Use the renderer for repeatable invoice drafts or template discovery:

python3 scripts/render_invoice.py --list
python3 scripts/render_invoice.py --stage milestone --list
python3 scripts/render_invoice.py --template pilot-deposit-invoice --var client_name=Acme --var invoice_number=INV-1001 --var amount_due=6000

If a user needs a polished production invoice, use the rendered draft as a starting point and replace every placeholder with verified facts.

Rendering to a Branded PDF

Artifacts from this skill are delivered as branded CompleteTech LLC PDF documents, not raw Markdown. The renderer emits the PDF (and prints the Markdown) in one command, using the same reportlab branding engine as the contract skill:

pip install -r requirements.txt
python3 scripts/render_invoice.py --template milestone-invoice \
  --out artifact.pdf --png artifact.png \
  --title "Invoice INV-2026-0461" --doc-type "MILESTONE INVOICE" \
  --meta "INVOICE NO.=INV-2026-0461" --meta "DUE=2026-06-23" --no-cover \
  --var client_name="Client Name" --var workflow="support triage"

• --no-pdf emits Markdown only (the original behavior); --no-cover drops the cover page.
• Already drafted the Markdown yourself? Render it directly: python3 scripts/render_pdf.py --markdown artifact.md --out artifact.pdf --logo assets/logo.png --title "...".
• The PDF supports a Markdown subset: #/##/### headings, paragraphs, - bullets, tables, > callouts, **bold**, and [PAGE_BREAK]. PDF requires reportlab==4.5.1; the optional --png preview requires pypdfium2==5.8.0 and pillow==12.2.0. See assets/examples/ for a rendered example.

Network Boundary

This skill is local-only. It does not include outbound network helpers, callbacks, or any helper that posts invoice run metadata to an external service.