{
  "what": "Check a whole bibliography or dependency manifest in one call.",
  "how": "POST items[] (or citations[] and packages[] shorthand), up to 25 items, with a pack code as the bearer token.",
  "pricing": {
    "answer_pack": "one credit per three items (US$0.0167 an item)",
    "lookup_pack": "one credit an item (US$0.02)",
    "per_call": "US$0.12 for up to 12 items on the x402 rail at this door (or on the MCP door, verify_bulk)"
  },
  "receipt": "One signed receipt covers the whole list, and each item is answered by the door that answers a single call.",
  "charged_for": "items that produced an answer — an unreadable source costs nothing"
}