AI Agents

AI coding assistants like Claude Code, Cursor, and Windsurf are transforming how developers build software. To help you integrate Creem faster and with best practices built-in, we’ve created an official Creem API Skill that gives AI assistants deep knowledge about our payment infrastructure.

Quick Install for Claude Code

Install the Creem skill with a single command:

/plugin marketplace add armitage-labs/creem

Then install the skill using either method: Option A: Use the interactive UI (easiest)

Type /plugin and press Enter
Go to the Discover tab
Search for creem-api
Press Enter to install

Option B: Use the command directly

/plugin install creem-api@creem-skills

That’s it! Claude Code now has complete knowledge of the Creem API and will generate production-ready integration code when you ask about payments, subscriptions, webhooks, or licenses.

The skill teaches your assistant how Creem works. If you also want it to act — create products, open checkouts, cancel subscriptions — add the MCP server, which exposes 49 API tools from the same creem package.

What is a Skill?

A skill is a structured set of instructions and reference materials that AI assistants use to provide more accurate, contextual help for specific tasks. When you load the Creem skill, your AI assistant gains comprehensive knowledge about:

Every documented API endpoint with request/response schemas
Webhook events and signature verification
Common integration patterns and workflows
Best practices for security and error handling
Test mode configuration

Get the Skill

Claude Code (Recommended)

One-line install via the plugin marketplace: /plugin marketplace add armitage-labs/creem

GitHub Repository

Browse or fork the skill files directly

Any Other Tool

Copy the folder into your project: npx degit armitage-labs/creem/packages/docs/skills/creem-api/skills/creem-api creem-skill

Skill Contents

The skill includes four comprehensive reference files:

File	Description
`SKILL.md`	Core skill with quick reference and implementation patterns
`REFERENCE.md`	Complete API reference with all endpoints and schemas
`WEBHOOKS.md`	Webhook events documentation with payload examples
`WORKFLOWS.md`	Step-by-step integration guides for common use cases

What’s Covered

API Endpoints

Checkouts: Create and retrieve checkout sessions
Products: Create, retrieve, and list products
Customers: Manage customers and portal links
Subscriptions: Full lifecycle management (get, update, upgrade, cancel, pause, resume)
Licenses: Activation, validation, and deactivation
Discounts: Create, retrieve, and delete promotional codes
Transactions: Query payment history

Webhook Events (13 types)

Event	Meaning
`checkout.completed`	Payment successful
`subscription.active`	New subscription created
`subscription.paid`	Recurring payment processed
`subscription.canceled`	Subscription ended
`subscription.scheduled_cancel`	Cancellation scheduled for period end
`subscription.past_due`	Payment failed, retries pending
`subscription.unpaid`	Payment collection failed
`subscription.expired`	Period ended without payment
`subscription.trialing`	Trial started
`subscription.paused`	Subscription paused
`subscription.update`	Subscription modified
`refund.created`	Refund processed
`dispute.created`	Chargeback opened

Integration Workflows

Basic SaaS subscription flows
One-time purchases with digital delivery
License key systems for desktop/mobile apps
Seat-based team billing
Freemium with upgrade flows
Affiliate and referral tracking

Best Practices

Webhook signature verification (HMAC-SHA256)
Error handling patterns
Test mode development
Security considerations
Idempotency and retry handling

Setup by AI Tool

Claude Code

Recommended Method: Use the plugin marketplace for the easiest setup experience.

One-Line Install (Plugin Marketplace) Claude Code’s plugin marketplace makes installation effortless:

Add the Marketplace

Open Claude Code and run:

/plugin marketplace add armitage-labs/creem

Install the Skill

Option A: Interactive UI (easiest)Type /plugin, go to the Discover tab, search for creem-api, and press Enter to install.Option B: Command

/plugin install creem-api@creem-skills

Start Building

Ask Claude to help with Creem integration:

Help me create a checkout flow for my SaaS product

Managing the Plugin

# View installed plugins
/plugin

# Disable the skill temporarily
/plugin disable creem-api@creem-skills

# Enable again
/plugin enable creem-api@creem-skills

# Uninstall
/plugin uninstall creem-api@creem-skills

# Update marketplace to get latest version
/plugin marketplace update creem-skills

Alternative: Direct Reference If you prefer not to use the marketplace, you can reference the skill directly in any conversation:

Help me integrate Creem payments. Use the skill at https://github.com/armitage-labs/creem

Cursor

Cursor supports adding context through multiple methods: Option 1: Add to Project

Pull just the skill directory into your project:

npx degit armitage-labs/creem/packages/docs/skills/creem-api/skills/creem-api .cursor/skills/creem-api

Reference the skill files in your conversations using @ mentions:

@.cursor/skills/creem-api/SKILL.md Help me create a checkout flow

Option 2: Custom Instructions Add the skill content to your project’s .cursorrules file:

When working with Creem payment integration:
- Use the Creem API at https://api.creem.io (or test-api.creem.io for test mode)
- Authenticate with x-api-key header
- Always verify webhook signatures using HMAC-SHA256
- Prices are in cents (1000 = $10.00)
- Reference: .cursor/skills/creem-api/

Option 3: Docs Integration Add the Creem documentation to Cursor’s docs:

Open Cursor Settings → Features → Docs
Add: https://docs.creem.io
Cursor will index our documentation for context

Windsurf

Windsurf supports custom knowledge through its Cascade feature:

Pull just the skill directory:

npx degit armitage-labs/creem/packages/docs/skills/creem-api/skills/creem-api .windsurf/creem

Add to your project’s knowledge base in Windsurf settings

Reference in conversations:

Using the Creem skill, help me implement subscription billing

Other AI Tools

For other AI coding assistants (GitHub Copilot Chat, Cody, Continue, etc.):

Pull the skill files into a dedicated folder:

npx degit armitage-labs/creem/packages/docs/skills/creem-api/skills/creem-api .ai/creem

Add that folder to your tool’s context or knowledge base
Reference in context when asking questions about Creem integration
Copy relevant sections into your conversation when needed

Most AI tools support adding files to conversation context - simply include the relevant skill file when working on payment integration.

Example Usage

Once the skill is loaded, you can ask natural language questions and get production-ready code:

Creating a Checkout

Create a checkout API route for my Next.js app that handles subscription purchases
with metadata tracking

// app/api/checkout/route.ts
import { NextRequest, NextResponse } from "next/server";

const CREEM_API_KEY = process.env.CREEM_API_KEY!;
const BASE_URL =
  process.env.NODE_ENV === "production" ? "https://api.creem.io" : "https://test-api.creem.io";

export async function POST(req: NextRequest) {
  const { productId, userId, email } = await req.json();

  const response = await fetch(`${BASE_URL}/v1/checkouts`, {
    method: "POST",
    headers: {
      "x-api-key": CREEM_API_KEY,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      product_id: productId,
      request_id: `checkout_${userId}_${Date.now()}`,
      success_url: `${process.env.NEXT_PUBLIC_APP_URL}/success`,
      customer: { email },
      metadata: { userId, source: "webapp" },
    }),
  });

  const checkout = await response.json();
  return NextResponse.json({ checkoutUrl: checkout.checkout_url });
}

Handling Webhooks

Create a webhook handler that verifies signatures and handles subscription events

// app/api/webhooks/creem/route.ts
import { NextRequest, NextResponse } from "next/server";
import { constructWebhookEventEntity } from "creem/webhooks";

export async function POST(req: NextRequest) {
  const rawBody = await req.text();
  const event = await constructWebhookEventEntity(rawBody, req.headers, {
    secret: process.env.CREEM_WEBHOOK_SECRET!,
  }).catch(() => null);

  if (!event) {
    return NextResponse.json({ error: "Invalid signature" }, { status: 401 });
  }

  switch (event.eventType) {
    case "checkout.completed":
      await handleCheckoutCompleted(event.object);
      break;
    case "subscription.paid":
      await handleSubscriptionPaid(event.object);
      break;
    case "subscription.canceled":
      await handleSubscriptionCanceled(event.object);
      break;
  }

  return NextResponse.json({ received: true });
}

License Key Integration

Implement license key activation and validation for my Electron desktop app

// license.ts (Electron)
import Store from "electron-store";
import { machineIdSync } from "node-machine-id";

const store = new Store<{ license: LicenseState }>();
// Your backend proxies these calls to Creem. The merchant API key
// never ships inside the desktop binary.
const LICENSE_API = "https://yourapp.com/api/license";

export async function activateLicense(licenseKey: string) {
  const instanceName = machineIdSync();

  const response = await fetch(`${LICENSE_API}/activate`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
      key: licenseKey,
      instance_name: instanceName,
    }),
  });

  if (!response.ok) {
    const error = await response.json();
    throw new Error(error.message || "Activation failed");
  }

  const license = await response.json();
  store.set("license", {
    key: licenseKey,
    instanceId: license.instance.id,
    expiresAt: license.expires_at,
  });

  return license;
}

export async function validateLicense() {
  const stored = store.get("license");
  if (!stored) return { valid: false, status: "not_activated" };

  const response = await fetch(`${LICENSE_API}/validate`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
      key: stored.key,
      instance_id: stored.instanceId,
    }),
  });

  const license = await response.json();
  return { valid: license.status === "active", status: license.status };
}

Why Use the Skill?

Faster Development

Skip reading documentation - describe what you want and get working code instantly

Best Practices Built-in

Generated code includes security patterns, error handling, and production considerations

Always Up-to-Date

We maintain the skill alongside our API - you always get current patterns

Comparison

Without Skill	With Skill
Read API docs, find endpoints	Describe your goal in plain English
Copy-paste examples, adapt manually	Get tailored, working code
Miss edge cases and best practices	Security and error handling included
Search for webhook payload formats	Full payload examples in context
Trial and error with parameters	Correct parameters from the start

Skill vs SDK

The Creem skill is designed for direct API integration and complements our SDKs:

Use the Skill When	Use an SDK When
Building custom integrations	Using Next.js, TypeScript, or Better Auth
Learning the API	Want type-safety and abstractions
Working with any language	Prefer pre-built components
Need full control over requests	Want faster development with helpers

The skill focuses on the REST API. For SDK-specific help, see our TypeScript SDK, Next.js SDK, or Better Auth documentation.

Contributing

Found an issue or want to improve the skill? We welcome contributions:

Report Issues

Found a bug or incorrect information? Let us know

Contribute

Submit improvements or new workflow examples

Next Steps

Install the Skill

Run /plugin marketplace add armitage-labs/creem in Claude Code

API Reference

Explore the full API documentation

Webhooks Guide

Learn about real-time event handling

Test Mode

Set up your development environment

Get Started

AI

Features

Code

Integrations

Community

Merchant of Record

For Customers

Quick Install for Claude Code

What is a Skill?

Get the Skill

Claude Code (Recommended)

GitHub Repository

Any Other Tool

Skill Contents

What’s Covered

Setup by AI Tool

Claude Code

Cursor

Windsurf

Other AI Tools

Example Usage

Creating a Checkout

Handling Webhooks

License Key Integration

Why Use the Skill?

Faster Development

Best Practices Built-in

Always Up-to-Date

Comparison

Skill vs SDK

Contributing

Report Issues

Contribute

Next Steps

Install the Skill

API Reference

Webhooks Guide

Test Mode

​Quick Install for Claude Code

​What is a Skill?

​Get the Skill

Claude Code (Recommended)

GitHub Repository

Any Other Tool

​Skill Contents

​What’s Covered

​Setup by AI Tool

​Claude Code

​Cursor

​Windsurf

​Other AI Tools

​Example Usage

​Creating a Checkout

​Handling Webhooks

​License Key Integration

​Why Use the Skill?

Faster Development

Best Practices Built-in

Always Up-to-Date

​Comparison

​Skill vs SDK

​Contributing

Report Issues

Contribute

​Next Steps

Install the Skill

API Reference

Webhooks Guide

Test Mode

Quick Install for Claude Code

What is a Skill?

Get the Skill

Skill Contents

What’s Covered

Setup by AI Tool

Claude Code

Cursor

Windsurf

Other AI Tools

Example Usage

Creating a Checkout

Handling Webhooks

License Key Integration

Why Use the Skill?

Comparison

Skill vs SDK

Contributing

Next Steps