curl --request GET \
  --url https://api.example.com/v1/sdk/purchases/{purchaseRef}

{
  "reference": "pur_1A2B3C4D",
  "customerRef": "cus_3C4D5E6F",
  "customerEmail": "customer@example.com",
  "productRef": "prd_1A2B3C4D",
  "status": "active",
  "amount": 9900,
  "currency": "GBP",
  "startDate": "<string>",
  "isRecurring": true,
  "createdAt": "<string>",
  "productName": "API Gateway Manager",
  "planSnapshot": {
    "price": 2999,
    "currency": "USD",
    "planType": "recurring",
    "reference": "pln_1A2B3C4D",
    "billingCycle": "monthly",
    "features": {},
    "limits": {},
    "meterRef": "mtr_1A2B3C4D",
    "limit": 5000,
    "freeUnits": 100,
    "creditsPerUnit": 1
  },
  "originalAmount": 10000,
  "exchangeRate": 1.3082,
  "endDate": "<string>",
  "paidAt": "<string>",
  "usage": {
    "used": 150,
    "overageUnits": 0,
    "overageCost": 0,
    "periodStart": "2025-10-01T00:00:00Z",
    "periodEnd": "2025-11-01T00:00:00Z"
  },
  "billingCycle": "weekly",
  "nextBillingDate": "<string>",
  "autoRenew": true,
  "cancelledAt": "<string>",
  "cancellationReason": "<string>",
  "metadata": {}
}