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 san-npm/skills-ws --skill saas-billinggit clone --depth 1 https://github.com/san-npm/skills-wsWrote 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/san-npm/skills-ws/saas-billing)<a href="https://agentmods.dev/skills/san-npm/skills-ws/saas-billing"><img src="https://agentmods.dev/badge/skills/san-npm/skills-ws/saas-billing/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/san-npm/skills-ws/saas-billing"><img src="https://agentmods.dev/badge/skills/san-npm/skills-ws/saas-billing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00065 | $0.00708 |
| Opus 5 | $0.00032 | $0.00354 |
| Sonnet 5 | $0.00013 | $0.00142 |
| Haiku 4.5 | $0.00006 | $0.00071 |
Grade A, and why
saas-billing 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 5d 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 — 42 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SaaS Billing with Stripe — Expert Skill
Disambiguation: this skill = Express/Node stack. For Next.js App Router + Server Actions billing, see
stripe-billing. This skill pins StripeapiVersion: '2026-06-24.dahlia';stripe-billingcurrently pins2025-09-30.clover.
Production-grade billing integration for SaaS applications using Stripe. Covers subscription, usage-based, and hybrid billing models with complete Express.js examples.
Safety gate
Before executing commands or changing external systems, confirm scope, credentials, target environment, rollback, and required approval. Pin and verify third-party artifacts; never expose secrets to client code or logs.
Reference guide
Read only the references needed for the current request:
- Table of Contents: references/table-of-contents.md
- Core Concepts: references/core-concepts.md
- Billing Models: references/billing-models.md
- Stripe Products & Prices: references/stripe-products-prices.md
- Checkout Sessions: references/checkout-sessions.md
- Stripe Tax: references/stripe-tax.md
- Adaptive Pricing (Local-Currency Checkout): references/adaptive-pricing-local-currency-checkout.md
- Subscription Lifecycle: references/subscription-lifecycle.md
- Webhook Handling: references/webhook-handling.md
- API Key Provisioning: references/api-key-provisioning.md
- Customer Portal: references/customer-portal.md
- Metered / Usage-Based Billing: references/metered-usage-based-billing.md
- Dunning & Failed Payments: references/dunning-failed-payments.md
- Security: references/security.md
- Testing: references/testing.md
- Common Mistakes: references/common-mistakes.md
- Complete Express.js Server Example: references/complete-express-js-server-example.md
- Quick Reference: Webhook Events Cheat Sheet: references/quick-reference-webhook-events-cheat-sheet.md
- Decision Flowchart: references/decision-flowchart.md
- Checklist: Go-Live: references/checklist-go-live.md
What ships with it
21 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- agents/openai.yaml 168 B
- references/adaptive-pricing-local-currency-checkout.md 2.6 KB
- references/api-key-provisioning.md 4.1 KB
- references/billing-models.md 1.5 KB
- references/checklist-go-live.md 785 B
- references/checkout-sessions.md 3.1 KB
- references/common-mistakes.md 3.2 KB
- references/complete-express-js-server-example.md 14 KB
- references/core-concepts.md 2.0 KB
- references/customer-portal.md 1.9 KB
- references/decision-flowchart.md 928 B
- references/dunning-failed-payments.md 1.8 KB
- references/metered-usage-based-billing.md 6.9 KB
- references/quick-reference-webhook-events-cheat-sheet.md 757 B
- references/security.md 3.3 KB
- references/stripe-products-prices.md 3.3 KB
- references/stripe-tax.md 6.0 KB
- references/subscription-lifecycle.md 8.7 KB
- references/table-of-contents.md 794 B
- references/testing.md 4.1 KB
- references/webhook-handling.md 14 KB
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.
- 5d ago First seen · 42 lines · 65 tokens per session scan A cfccd8d65da1
saas-billing is a skill published in the GitHub repository san-npm/skills-ws (2 stars, last pushed 5d ago), licensed MIT. It adds 65 tokens to every session and 708 once invoked, about $0.0003 per session on Opus 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 2026-09-07.
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