{
  "contract": "username_registry",
  "version": "1.0.0",
  "description": "Maps human-readable usernames to wallet addresses. Shorter names cost more to register. Fees go to the contract treasury.",
  "methods": [
    {
      "name": "register",
      "description": "Register a username for the caller. Fee = 10^(7 - min(len,6)) µT (1-char=10M, 2=1M, 3=100K, 4=10K, 5=1K, 6+=100). Caller must have sufficient balance.",
      "args": [
        {"name": "name", "type": "string", "description": "Username to register (max 64 chars, lowercase)"}
      ]
    },
    {
      "name": "resolve",
      "description": "Look up the wallet address that owns a username. Logs 'owner: <address>' or 'not found: <name>'.",
      "args": [
        {"name": "name", "type": "string", "description": "Username to look up"}
      ]
    },
    {
      "name": "lookup",
      "description": "Reverse lookup: find the username registered to a given address. Logs 'name: <username>' or 'no name: <address>'.",
      "args": [
        {"name": "address", "type": "string", "description": "Wallet address (hex pubkey)"}
      ]
    },
    {
      "name": "transfer",
      "description": "Transfer ownership of a username to another address. Only the current owner may call this.",
      "args": [
        {"name": "name", "type": "string", "description": "Username to transfer"},
        {"name": "new_owner", "type": "string", "description": "New owner address (hex pubkey)"}
      ]
    },
    {
      "name": "release",
      "description": "Release a username registration. Only the current owner may call this.",
      "args": [
        {"name": "name", "type": "string", "description": "Username to release"}
      ]
    },
    {
      "name": "fee",
      "description": "Query the registration fee for a given name length. Logs 'fee: <amount>' in µT.",
      "args": [
        {"name": "name", "type": "string", "description": "Name whose fee you want to check"}
      ]
    }
  ]
}