curl -X POST https://api.stateset.com/v1/checkouts \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "items": [
      {
        "id": "item_123",
        "quantity": 2
      }
    ],
    "buyer": {
      "first_name": "John",
      "last_name": "Doe",
      "email": "john.doe@example.com",
      "phone_number": "+1234567890"
    },
    "fulfillment_address": {
      "name": "John Doe",
      "line_one": "123 Main St",
      "line_two": "Apt 4B",
      "city": "San Francisco",
      "state": "CA",
      "country": "US",
      "postal_code": "94105"
    }
  }'

const checkout = await stateset.checkouts.create({
  items: [
    {
      id: "item_123",
      quantity: 2
    }
  ],
  buyer: {
    first_name: "John",
    last_name: "Doe",
    email: "john.doe@example.com",
    phone_number: "+1234567890"
  },
  fulfillment_address: {
    name: "John Doe",
    line_one: "123 Main St",
    line_two: "Apt 4B",
    city: "San Francisco",
    state: "CA",
    country: "US",
    postal_code: "94105"
  }
});

checkout = stateset.checkouts.create(
    items=[
        {
            "id": "item_123",
            "quantity": 2
        }
    ],
    buyer={
        "first_name": "John",
        "last_name": "Doe",
        "email": "john.doe@example.com",
        "phone_number": "+1234567890"
    },
    fulfillment_address={
        "name": "John Doe",
        "line_one": "123 Main St",
        "line_two": "Apt 4B",
        "city": "San Francisco",
        "state": "CA",
        "country": "US",
        "postal_code": "94105"
    }
)

{
  "id": "checkout_abc123",
  "buyer": {
    "first_name": "John",
    "last_name": "Doe",
    "email": "john.doe@example.com",
    "phone_number": "+1234567890"
  },
  "payment_provider": {
    "provider": "stripe",
    "supported_payment_methods": ["card"]
  },
  "status": "ready_for_payment",
  "currency": "usd",
  "line_items": [
    {
      "id": "item_123",
      "item": {
        "id": "item_123",
        "quantity": 2
      },
      "base_amount": 2000,
      "discount": 0,
      "total": 2000,
      "subtotal": 2000,
      "tax": 0
    }
  ],
  "fulfillment_address": {
    "name": "John Doe",
    "line_one": "123 Main St",
    "line_two": "Apt 4B",
    "city": "San Francisco",
    "state": "CA",
    "country": "US",
    "postal_code": "94105"
  },
  "fulfillment_options": [
    {
      "type": "shipping",
      "id": "shipping_fast",
      "title": "Express Shipping",
      "subtitle": "2-3 business days",
      "carrier": "Shipping Co",
      "subtotal": 150,
      "tax": 0,
      "total": 150
    }
  ],
  "fulfillment_option_id": "shipping_fast",
  "totals": [
    {
      "type": "subtotal",
      "display_text": "Subtotal",
      "amount": 2000
    },
    {
      "type": "fulfillment",
      "display_text": "Shipping",
      "amount": 150
    },
    {
      "type": "tax",
      "display_text": "Tax",
      "amount": 100
    },
    {
      "type": "total",
      "display_text": "Total",
      "amount": 2250
    }
  ],
  "messages": [],
  "links": []
}

{
  "success": false,
  "error": {
    "type": "invalid_request",
    "code": "VALIDATION_ERROR",
    "message": "Invalid request parameters",
    "details": {
      "items": "At least one item is required",
      "buyer.email": "Invalid email format"
    }
  }
}