Batch upsert customers by external ID

Create or update multiple customers by external system ID. Supports up to 100 customers per request with stale update protection.

Related endpoints

• GET /customers/{customerId}/invoices — List customer invoices
• GET /customers/{customerId}/subscriptions — List customer subscriptions
• GET /customers/{customerId}/orders — List customer orders
• GET /customers/{customerId}/payments — List customer payments
• POST /customers — Create a new customer
• GET /customers — List customers
• GET /customers/{id} — Get customer by ID
• PATCH /customers/{id} — Update customer details

Common errors

• 400 invalid_request — malformed payload or failed validation.
• 401 unauthenticated — missing, malformed, or revoked API key.
• 403 permission_denied — key lacks the required scope, or the resource belongs to a different merchant.

Idempotency

Pass an Idempotency-Key header (UUID v4 recommended) to make retries safe. Keys are valid for 24 hours; see the idempotency guide.

curl -X PUT "https://api.revkeen.com/v2/customers/external/batch" \  -H "x-api-key: $REVKEEN_API_KEY" \  -H "Content-Type: application/json" \  -d '{    "source": "practicehub",    "customers": [      {        "external_id": "PAT-12345",        "email": "john@example.com",        "name": "John Doe",        "phone": "+1-555-123-4567",        "address_line1": "string",        "address_line2": "string",        "city": "string",        "state": "string",        "postal_code": "string",        "country": "US",        "tax_id": "string",        "tax_id_country": "string",        "notes": "string",        "metadata": {},        "external_updated_at": "2026-01-01T00:00:00Z"      }    ]  }'

{
  "created": 5,
  "updated": 10,
  "skipped": 2,
  "failed": [
    {
      "external_id": "string",
      "error": "string"
    }
  ]
}