Create a customer group

import { createAdminClient } from '@spree/admin-sdk'

const client = createAdminClient({
  baseUrl: 'https://your-store.com',
  secretKey: 'sk_xxx',
})

const group = await client.customerGroups.create({
  name: 'VIP customers',
  description: 'Top spenders, eligible for early access',
  customer_ids: ['cus_UkLWZg9DAJ', 'cus_QrLWXg9CAJ'],
})

spree api post /customer_groups -d '{"name":"VIP customers","description":"Top spenders, eligible for early access","customer_ids":["cus_UkLWZg9DAJ","cus_QrLWXg9CAJ"]}'

{
  "id": "cg_EfhxLZ9ck8",
  "name": "Wholesale 2",
  "description": "B2B accounts",
  "customers_count": 1,
  "created_at": "2026-07-26T14:24:21.376Z",
  "updated_at": "2026-07-26T14:24:21.376Z"
}

{
  "error": {
    "code": "validation_error",
    "message": "Name can't be blank",
    "details": {
      "name": [
        "can't be blank"
      ]
    }
  }
}