{
  "contact_email": "transparency@programmatic-lab.dev",
  "contact_address": "Programmatic Lab, educational simulation",
  "version": "1.0",
  "sellers": [
    {
      "seller_id": "pub-atlas-1001",
      "seller_type": "PUBLISHER",
      "name": "Programmatic Lab Publishing",
      "domain": "programmatic-lab.dev",
      "is_confidential": 0,
      "ext": { "advertising_system": "ssp-atlas.example" }
    },
    {
      "seller_id": "origin-publisher-01",
      "seller_type": "PUBLISHER",
      "name": "Programmatic Lab Publishing",
      "domain": "programmatic-lab.dev",
      "is_confidential": 0,
      "ext": { "advertising_system": "ssp-origin.example" }
    },
    {
      "seller_id": "pub-beacon-2001",
      "seller_type": "INTERMEDIARY",
      "name": "Beacon Resale Partners",
      "domain": "beacon-resale.example",
      "is_confidential": 0,
      "ext": { "advertising_system": "ssp-beacon.example" }
    },
    {
      "seller_id": "pub-cascade-3001",
      "seller_type": "PUBLISHER",
      "name": "Programmatic Lab Publishing",
      "domain": "programmatic-lab.dev",
      "is_confidential": 0,
      "ext": { "advertising_system": "ssp-cascade.example" }
    }
  ],
  "ext": {
    "programmatic_lab": {
      "simulated": true,
      "note": "Combined educational snapshot. In production, each advertising system publishes its own sellers.json file."
    }
  }
}