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

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

const { stock_level_count } = await client.stockLevels.bulkUpsert({
  stock_levels: [
    {
      variant_id: 'variant_xxx',
      stock_location_id: 'sloc_xxx',
      count_on_hand: 42,
    },
  ],
})

spree api post /stock_levels/bulk_upsert -d '{"stock_levels":[{"variant_id":"variant_xxx","stock_location_id":"sloc_xxx","count_on_hand":42}]}'

{
  "stock_level_count": 1
}

{
  "error": {
    "code": "invalid_stock_levels",
    "message": "Each row must name a variant and stock location in this store, and either a count_on_hand or an adjustment.",
    "details": {
      "rows": [
        {
          "index": 0,
          "missing": [
            "count_on_hand"
          ]
        }
      ]
    }
  }
}