Una sola API para todos los canales en los que vendes

curl https://api.nembol.com/rest/v1/products?sku=MUG-1 \
  -H "Authorization: Bearer $NEMBOL_API_KEY" \
  -H "Nembol-Account: acct_66f0a1"   # partners only

{
  "data": [{
    "id": "prod_51aa", "title": "Ceramic mug",
    "variants": [{ "sku": "MUG-1", "quantity": 12 }],
    "listings": [
      { "channel": "shopify", "status": "listed" },
      { "channel": "etsy",    "status": "listed" }
    ]
  }]
}