Building an SPL Token in Solidity Syntax

Tokens are the building block of DeFi. On Ethereum, you write ERC-20 contracts. On Solana, tokens use the SPL Token standard. With SolScript, you write token contracts in Solidity syntax and the compiler generates the correct SPL Token interactions.

The Token Contract

Here’s a complete token contract in SolScript:

contract Token {
    string public name;
    string public symbol;
    uint8 public decimals = 9;
    uint256 public totalSupply;
    mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;
    address public owner;

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

    error InsufficientBalance(uint256 available, uint256 required);
    error InsufficientAllowance(uint256 available, uint256 required);
    error Unauthorized();

    modifier onlyOwner() {
        if (msg.sender != owner) revert Unauthorized();
        _;
    }

    constructor(string memory _name, string memory _symbol, uint256 _initialSupply) {
        name = _name;
        symbol = _symbol;
        owner = msg.sender;
        if (_initialSupply > 0) {
            _mint(msg.sender, _initialSupply);
        }
    }

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

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

    function mint(address to, uint256 amount) public onlyOwner {
        _mint(to, amount);
    }

    function burn(uint256 amount) public {
        if (balanceOf[msg.sender] < amount) {
            revert InsufficientBalance(balanceOf[msg.sender], amount);
        }
        balanceOf[msg.sender] -= amount;
        totalSupply -= amount;
    }

    function _transfer(address from, address to, uint256 amount) internal {
        if (balanceOf[from] < amount) {
            revert InsufficientBalance(balanceOf[from], amount);
        }
        balanceOf[from] -= amount;
        balanceOf[to] += amount;
        emit Transfer(from, to, amount);
    }

    function _mint(address to, uint256 amount) internal {
        totalSupply += amount;
        balanceOf[to] += amount;
        emit Transfer(address(0), to, amount);
    }
}

What SolScript Generates

When compiled, SolScript produces:

1. Account structures for token state and per-user balance PDAs
2. Anchor instructions for initialize, transfer, approve, mint, and burn
3. PDA derivation for the balanceOf and allowance mappings
4. Access control via signer validation for the onlyOwner modifier
5. Events emitted as Anchor events

Deploying the Token

1. Open the SolScript Playground
2. Paste the token contract
3. Click Compile to verify it builds
4. Connect your Solana wallet (Phantom or Solflare)
5. Select Devnet as the network
6. Click Deploy

Your token is now live on Solana devnet. You can interact with it using any Solana wallet or SDK.

Next Steps

• Add a pause mechanism for emergency stops
• Implement transferFrom with allowance checking
• Browse the full token example for the complete implementation