{
  "contract": "auction",
  "version": "1.0.0",
  "description": "English auction with on-chain token escrow. Bids are locked in the contract treasury. When an auction settles, the seller receives the top bid; outbid funds are automatically refunded.",
  "methods": [
    {
      "name": "create",
      "description": "Create a new auction. Logs 'created: <auction_id>'. auction_id = block_height:seq (seq auto-incremented).",
      "args": [
        {"name": "title",     "type": "string",  "description": "Human-readable item title (max 128 chars)"},
        {"name": "min_bid",   "type": "uint64",  "description": "Minimum opening bid in µT"},
        {"name": "duration",  "type": "uint64",  "description": "Duration in blocks"}
      ]
    },
    {
      "name": "bid",
      "description": "Place a bid on an open auction. Caller transfers bid amount to the contract treasury; previous top bidder is refunded. Logs 'bid: <auction_id>'.",
      "args": [
        {"name": "auction_id", "type": "string", "description": "Auction ID returned by create"},
        {"name": "amount",     "type": "uint64", "description": "Bid amount in µT (must exceed current top bid)"}
      ]
    },
    {
      "name": "settle",
      "description": "Settle an ended auction. Transfers winning bid to seller. Anyone may call after the end block. Logs 'settled: <auction_id>'.",
      "args": [
        {"name": "auction_id", "type": "string", "description": "Auction ID to settle"}
      ]
    },
    {
      "name": "cancel",
      "description": "Cancel an auction before any bids. Only the seller may cancel. Logs 'cancelled: <auction_id>'.",
      "args": [
        {"name": "auction_id", "type": "string", "description": "Auction ID to cancel"}
      ]
    },
    {
      "name": "info",
      "description": "Query auction info. Logs 'seller: ...', 'title: ...', 'top_bid: ...', 'end_block: ...', 'status: open/settled/cancelled'.",
      "args": [
        {"name": "auction_id", "type": "string", "description": "Auction ID"}
      ]
    }
  ]
}