ArrowPadToken

[
  {
    "inputs": [
      {
        "internalType": "string",
        "name": "name_",
        "type": "string"
      },
      {
        "internalType": "string",
        "name": "symbol_",
        "type": "string"
      },
      {
        "internalType": "string",
        "name": "metadataURI_",
        "type": "string"
      },
      {
        "internalType": "uint256",
        "name": "supply_",
        "type": "uint256"
      },
      {
        "internalType": "address",
        "name": "recipient_",
        "type": "address"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "constructor"
  },
  {
    "inputs": [],
    "name": "InsufficientAllowance",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "InsufficientBalance",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "ZeroAddress",
    "type": "error"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "owner",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "spender",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "value",
        "type": "uint256"
      }
    ],
    "name": "Approval",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "from",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "value",
        "type": "uint256"
      }
    ],
    "name": "Transfer",
    "type": "event"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "name": "allowance",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "spender",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "approve",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "name": "balanceOf",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "decimals",
    "outputs": [
      {
        "internalType": "uint8",
        "name": "",
        "type": "uint8"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "launchpad",
    "outputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "metadataURI",
    "outputs": [
      {
        "internalType": "string",
        "name": "",
        "type": "string"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "name",
    "outputs": [
      {
        "internalType": "string",
        "name": "",
        "type": "string"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "symbol",
    "outputs": [
      {
        "internalType": "string",
        "name": "",
        "type": "string"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "totalSupply",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "transfer",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "from",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "transferFrom",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  }
]

// SPDX-License-Identifier: MIT
pragma solidity 0.8.31;

/// @title ArrowPadToken — launched on https://arrowpad.fun · fixed supply, no owner, LP locked forever
/// @notice Fixed-supply ERC-20 deployed by the launchpad factory.
/// @dev Security properties (by construction, verifiable on-chain):
///      - Total supply is minted once in the constructor and can never change
///        (no mint function exists).
///      - There is no owner, no admin, no pause, no blacklist, no transfer tax
///        and no upgrade path.
///      - Metadata is immutable after deployment.
contract ArrowPadToken {
    string public name;
    string public symbol;
    uint8 public constant decimals = 18;
    uint256 public immutable totalSupply;

    /// @notice Off-chain metadata (JSON: description, image, links). Immutable.
    string public metadataURI;

    /// @notice The factory that deployed this token.
    address public immutable launchpad;

    mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);

    error InsufficientBalance();
    error InsufficientAllowance();
    error ZeroAddress();

    constructor(
        string memory name_,
        string memory symbol_,
        string memory metadataURI_,
        uint256 supply_,
        address recipient_
    ) {
        name = name_;
        symbol = symbol_;
        metadataURI = metadataURI_;
        launchpad = msg.sender;
        totalSupply = supply_;
        balanceOf[recipient_] = supply_;
        emit Transfer(address(0), recipient_, supply_);
    }

    function transfer(address to, uint256 amount) external returns (bool) {
        return _transfer(msg.sender, to, amount);
    }

    function transferFrom(address from, address to, uint256 amount) external returns (bool) {
        uint256 allowed = allowance[from][msg.sender];
        if (allowed != type(uint256).max) {
            if (allowed < amount) revert InsufficientAllowance();
            unchecked {
                allowance[from][msg.sender] = allowed - amount;
            }
        }
        return _transfer(from, to, amount);
    }

    function approve(address spender, uint256 amount) external returns (bool) {
        allowance[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    function _transfer(address from, address to, uint256 amount) internal returns (bool) {
        if (to == address(0)) revert ZeroAddress();
        uint256 fromBalance = balanceOf[from];
        if (fromBalance < amount) revert InsufficientBalance();
        unchecked {
            balanceOf[from] = fromBalance - amount;
            balanceOf[to] += amount;
        }
        emit Transfer(from, to, amount);
        return true;
    }
}