Audit Payment System

Q: What is a Claude Code skill and how does the Audit Payment System skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Audit Payment System is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Security category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Security · Sub-category: security-misc · Last updated: 2026-07-25

tool:stripe type:audit

Read-only audit for payment/money-movement systems, scope-gated so a simple Stripe-Checkout site and an in-house ledger/gateway each see only relevant findings. Checks the things that lose money or trigger PCI liability: idempotency on every mutation (double-charge on retry), double-entry append-only ledger, payment state machine (no double-capture), sync-auth vs async-webhook flow, HMAC + event-id webhook dedup, 3-way reconciliation vs PSP settlement, fraud/velocity + 3DS/SCA, multi-currency in minor units, PCI DSS v4.0.1 (never log PAN, tokens only, key rotation), and resilience (PSP timeout, partial ledger write, breaker). Uses the Stripe MCP for version-anchored provider checks when the PSP is Stripe. Use when "audit payment system", "payment gateway audit", "double charge / idempotency", "ledger / reconciliation", "webhook / 3DS / PCI", or "audit-payment-system". Defers per-call resilience to audit-resilience, PCI/secrets to audit-security, ledger schema to audit-db-schema.

Security AStatic scan found no risk patternsHow grading works ›

From the source SKILL.md

Payment code fails differently from normal CRUD. A dropped PUT is an annoyance; a retried charge is a double-charge, a lost ledger write is money that vanished, a logged PAN is PCI liability, and an unverified webhook is a spoofed "payment succeeded". The bugs are silent — everything looks green until a customer is charged twice or the month-end books don't balance. This audit checks the controls that keep every cent accounted for and every charge exactly-once.

What this skill does

Audit Payment System is a community-contributed Claude Code skill in the security-misc sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/audit-payment-system/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use when "audit payment system", "payment gateway audit", "double charge / idempotency", "ledger / reconciliation", "webhook / 3DS / PCI", or "audit-payment-system". Defers per-call resilience to audit-resilience, PCI/secrets to audit-security, ledger schema to audit-db-schema.

Who uses this skill

The Audit Payment System Claude Code skill is built for security engineers, penetration testers, DevSecOps practitioners, and development teams hardening codebases and infrastructure. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 159,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/audit-payment-system
curl -L https://claudskills.com/skills/audit-payment-system/SKILL.md \
  -o ~/.claude/skills/audit-payment-system/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/audit-payment-system/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/audit-payment-system/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\audit-payment-system\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Audit Payment System Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/audit-payment-system/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Audit Payment System skill do?

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Audit Payment System skill?

Use Audit Payment System when your Claude Code task falls under the Security category — specifically in the security misc area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Audit Payment System" or describe the task and let Claude pick). Browse related skills at /category/security/.

What is a Claude Code skill and how does the Audit Payment System skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Audit Payment System is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Security category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/kensaurus/cursor-kenji/blob/HEAD/skills/audit-payment-system/SKILL.md
License: MIT
Author: kensaurus
Website: https://github.com/kensaurus/cursor-kenji

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

kensaurus. (2026). Audit Payment System [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/audit-payment-system/

BibTeX

@misc{audit-payment-system-2026,
  author    = {kensaurus},
  title     = {Audit Payment System [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/audit-payment-system/}
}

Embed this skill

Promote, attribute, or link this skill from your own README, blog post, or documentation. All three snippets are free to use — no sign-up, no API key. More distribution surfaces →

Badge

[![ClaudSkills](https://claudskills.com/badge/audit-payment-system.svg)](https://claudskills.com/skills/audit-payment-system/?utm_source=badge&utm_medium=readme&utm_campaign=skill_badge)

Security scan

Grade A · scanned 2026-07-25 — free static scan against the OWASP Agentic Skills Top 10.

No risk patterns were found in any of the ten OWASP-aligned categories. How grading works ›

✓ Prompt injection
✓ Data exfiltration
✓ Supply chain
✓ Reverse shell
✓ Credentials
✓ Execution
✓ Filesystem
✓ Persistence
✓ Obfuscation
✓ Network

Show this grade on your repo (click to copy):

[![Security: A](https://img.shields.io/badge/Security-A-2e7d32)](https://claudskills.com/skills/audit-payment-system/#security)

More Security skills

Browse all Security skills in the ClaudSkills registry, or explore these other picks from the same category:

Browse all Security skills → Top 100 skills

Part of ClaudSkills — the open registry for Claude Skills & Claude Code Skills. · What's New · Install guide · About · llms.txt

Part of Acreator Store — Adam Lankamer's AI tools: PerfectStudio · Ucaption · UTagger · AutoXPoster · TestYourSkills · AutomationFlows · Au Naturel · Telegram @acreatorstore