pn-payment-integration

pn-payment-integration is a skill for Cursor from perniemann/pnCore. It costs 34 tokens per session (453 once invoked), scanned A, original, MIT.

A guide to adding Stripe, PayPal, or Square payments, including checkout, recurring billing, and payment-event webhooks.

In plain words
What is it for?
Use it when building checkout forms, subscriptions, billing flows, payment webhooks, or moving from test payments to live payments.
Why use it?
It helps avoid common payment failures and security mistakes, such as mishandled retries, refunds, disputes, or exposed card data.

Skill for Cursor

Written for Cursor: shipped in a Cursor plugin.

Part of the pn-core plugin — 133 skills, 19 commands, 9 agents, 1 MCP server shipped together

Good fit Use it when building checkout forms, subscriptions, billing flows, payment webhooks, or moving from test payments to live payments.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/perniemann/pncore/pn-payment-integration
Install

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.

Any agent
npx skills add perniemann/pnCore --skill pn-payment-integration
Clone the repo
git clone --depth 1 https://github.com/perniemann/pnCore

Made for: Cursor.

Or install pn-core, the plugin that ships this one along with the rest of its 133 skills, 19 commands, 9 agents, 1 MCP server.

Wrote 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.

agentmods badge for pn-payment-integration

README.md
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Your own site
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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.

agentmods 80×15 button for pn-payment-integration

Your own site · 80×15
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Per session 34 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 453 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00034 $0.00453
Opus 5 $0.00017 $0.00227
Sonnet 5 $0.00007 $0.00091
Haiku 4.5 $0.00003 $0.00045

Measured 6d ago against content hash c55dcbc9b9ae, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

pn-payment-integration 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 6d 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.

packages/pn-core-mcp/content/skills/backend/pn-payment-integration/SKILL.md · 53 lines

What it actually says

Payment integration

When to use

  • Implementing payments, billing, or subscription features
  • Checkout flows and payment forms
  • Webhook handling for payment events
  • Migrating from test to production payment mode

When Stripe MCP is available: Use its tools for Stripe API lookups, product/price/subscription schema, SDK examples, and Stripe-specific operations. Combine with this skill for checkout patterns, webhooks, idempotency, and PCI guidance. Do not duplicate Stripe docs manually when MCP can provide them.

Focus areas

  • Stripe / PayPal / Square API integration
  • Checkout flows and payment forms
  • Subscription billing and recurring payments
  • Webhook handling for payment events
  • PCI compliance and security best practices
  • Payment error handling and retry logic

Approach

  1. Security first — Never log sensitive card data; use official SDKs.
  2. Idempotency — Implement for all payment operations (create intent, confirm, refund).
  3. Edge cases — Handle failed payments, disputes, refunds, webhook retries.
  4. Test mode first — Clear migration path to production; separate API keys per environment.
  5. Webhooks — Comprehensive handling for async events; verify signatures; handle duplicate delivery.

Output

  • Payment integration code with error handling
  • Webhook endpoint implementations (verify signature, idempotent handlers)
  • Database schema for payment records (status, idempotency keys)
  • Security checklist (PCI compliance points)
  • Test payment scenarios and edge cases
  • Environment variable configuration (API keys, webhook secrets)

Sources

Guardrails

  • Always use official SDKs; include both server-side and client-side code where needed
  • Reference pn-security-audit for auth and API security
  • Reference pn-node-api for env/secrets and error handling
Changes

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.

  1. 6d ago First seen · 53 lines · 34 tokens per session scan A c55dcbc9b9ae

Subscribe to this mod's changes

pn-payment-integration is a skill published in the GitHub repository perniemann/pnCore (0 stars, last pushed 3d ago), licensed MIT. It adds 34 tokens to every session and 453 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 2026-09-03.