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

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

// The units leave the source warehouse here.
const stockTransfer = await client.stockTransfers.markInTransit('st_1234567890')

spree api patch /stock_transfers/{id}/mark_in_transit -d '{ ... }'

{
  "id": "st_UkLWZg9DAJ",
  "number": "T1001",
  "reference": "Weekly restock",
  "created_at": "2026-01-15T12:00:00.000Z",
  "updated_at": "2026-01-15T12:00:00.000Z",
  "source_location_id": "sloc_UkLWZg9DAJ",
  "destination_location_id": "sloc_gbHJdmfrXB",
  "status": "in_transit",
  "notes": null,
  "metadata": {},
  "close_reason": null,
  "items_count": 1,
  "quantity_received_total": 0,
  "quantity_rejected_total": 0,
  "shipped_at": "2026-01-15T12:00:00.000Z",
  "received_at": null,
  "closed_short_at": null,
  "deleted_at": null,
  "closed_short": false,
  "quantity_shipped_total": 10,
  "editable": false
}