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 seaworld008/Commonly-used-high-value-skills --skill billing-automationgit clone --depth 1 https://github.com/seaworld008/Commonly-used-high-value-skillsWrote 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/seaworld008/commonly-used-high-value-skills/billing-automation)<a href="https://agentmods.dev/skills/seaworld008/commonly-used-high-value-skills/billing-automation"><img src="https://agentmods.dev/badge/skills/seaworld008/commonly-used-high-value-skills/billing-automation/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/seaworld008/commonly-used-high-value-skills/billing-automation"><img src="https://agentmods.dev/badge/skills/seaworld008/commonly-used-high-value-skills/billing-automation.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Agent Snooping · line 8 Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.Fix: Remove all code or instructions that list or read other skills' files or directories. Skills should operate independently; cross-skill access is a privilege escalation.
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 | $0.00040 | $0.00959 |
| Opus 5 | $0.00020 | $0.00479 |
| Sonnet 5 | $0.00008 | $0.00192 |
| Haiku 4.5 | $0.00004 | $0.00096 |
Grade A, and why
billing-automation 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 13d 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 — 142 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Billing Automation
Master automated billing systems including recurring billing, invoice generation, dunning management, proration, and tax calculation.
When to Use This Skill
- Implementing SaaS subscription billing
- Automating invoice generation and delivery
- Managing failed payment recovery (dunning)
- Calculating prorated charges for plan changes
- Handling sales tax, VAT, and GST
- Processing usage-based billing
- Managing billing cycles and renewals
Core Concepts
1. Billing Cycles
Common Intervals:
- Monthly (most common for SaaS)
- Annual (discounted long-term)
- Quarterly
- Weekly
- Custom (usage-based, per-seat)
2. Subscription States
trial → active → past_due → canceled
→ paused → resumed
3. Dunning Management
Automated process to recover failed payments through:
- Retry schedules
- Customer notifications
- Grace periods
- Account restrictions
4. Proration
Adjusting charges when:
- Upgrading/downgrading mid-cycle
- Adding/removing seats
- Changing billing frequency
Quick Start
from billing import BillingEngine, Subscription
# Initialize billing engine
billing = BillingEngine()
# Create subscription
subscription = billing.create_subscription(
customer_id="cus_123",
plan_id="plan_pro_monthly",
billing_cycle_anchor=datetime.now(),
trial_days=14
)
# Process billing cycle
billing.process_billing_cycle(subscription.id)
Detailed patterns and worked examples
Detailed pattern documentation lives in references/details.md. Read that file when the navigation tier above is insufficient.
Implementation Checklist
Before building or changing billing logic, capture:
- Product catalog: plan ids, prices, currency, billing interval, trial rules, and included usage.
- Customer lifecycle: signup, trial conversion, renewal, pause, resume, cancellation, and reactivation.
- Payment failure policy: retry cadence, email/SMS notices, grace period, account restrictions, and final cancellation behavior.
- Proration rules: upgrades, downgrades, seat changes, coupons, taxes, refunds, and invoice credits.
- Ledger model: immutable invoice records, payment attempts, adjustments, and audit metadata.
- Compliance constraints: tax invoices, receipts, PCI boundaries, refund approvals, and data-retention requirements.
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.
- 13d ago First seen · 142 lines · 40 tokens per session scan A f197cebea2d2
billing-automation is a skill published in the GitHub repository seaworld008/Commonly-used-high-value-skills (70 stars, last pushed 5d ago), licensed MIT. It adds 40 tokens to every session and 959 once invoked, about $0.0002 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 2026-08-30.
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stock-explorer
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asc-ppp-pricing
Set territory-specific pricing for subscriptions and in-app purchases using current asc setup, pricing summary, price import, and price schedule commands. Use when adjusting prices by country or implementing localized PPP strategies.