Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add cwinvestments/memstack --skill invoice-generatorgit clone --depth 1 https://github.com/cwinvestments/memstackWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/cwinvestments/memstack/invoice-generator)<a href="https://agentmods.dev/skills/cwinvestments/memstack/invoice-generator"><img src="https://agentmods.dev/badge/skills/cwinvestments/memstack/invoice-generator/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/cwinvestments/memstack/invoice-generator"><img src="https://agentmods.dev/badge/skills/cwinvestments/memstack/invoice-generator.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00057 | $0.02199 |
| Opus 5.5 | $0.00023 | $0.00880 |
| Sonnet 5.5 | $0.00011 | $0.00440 |
| Haiku 4.5 | $0.00006 | $0.00220 |
Grade A, and why
memstack-business-invoice-generator scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 259 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Invoice Generator: Creating professional invoice...
Generates professional invoices with line items, tax calculations, payment terms, due dates, and payment instructions. Output as structured markdown ready for PDF conversion.
Activation
When this skill activates, output:
Invoice Generator: Creating professional invoice...
Then execute the protocol below.
Context Guard
| Context | Status |
|---|---|
| User says "invoice", "generate invoice", "create invoice", "bill client" | ACTIVE |
| User says "line items" or "payment terms" | ACTIVE |
| User needs a professional invoice for a client | ACTIVE |
| User wants a contract or service agreement | DORMANT: use Contract Template |
| User wants financial projections | DORMANT: use Financial Model |
Common Mistakes
| Mistake | Why It's Wrong |
|---|---|
| "No invoice number" | Sequential invoice numbers are required for accounting and tax compliance. |
| "Vague line items" | "Consulting: $5,000" invites disputes. Itemize by deliverable, hours, or phase. |
| "No payment terms" | Without explicit terms (Net 30, due on receipt), clients have no obligation to pay on time. |
| "Skip tax line" | Even if tax is $0, show the tax line. It demonstrates professionalism and compliance. |
| "No late payment terms" | Without stated consequences, you have no leverage on overdue invoices. |
Protocol
Step 1: Gather Invoice Details
If the user hasn't provided details, ask:
- Client: company name, contact person, billing address
- Your business: business name, address, tax ID / EIN (if applicable)
- Line items: what are you billing for? (description, quantity, rate)
- Payment terms: Net 30, Net 15, due on receipt?
- Tax: applicable tax rate? (state sales tax, VAT, or exempt)
- Currency: USD, EUR, GBP, etc.?
Step 2: Generate Invoice Number
Invoice numbering convention:
[PREFIX]-[YEAR][MONTH]-[SEQUENCE]
Example: INV-202603-001
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago Changed 1738909c91e4
- 1mo ago First seen · 259 lines · 57 tokens per session scan A d406928ea20d
memstack-business-invoice-generator is a skill published in the GitHub repository cwinvestments/memstack (425 stars, last pushed today), licensed MIT. It adds 57 tokens to every session and 2,199 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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