Built-in Functions Reference

Chain Object

The Chain object provides blockchain interaction capabilities within smart contracts.

Metadata Management

// Store data in contract storage
Chain.store(key, value);

// Retrieve data from contract storage
const data = Chain.load(key);

// Delete data from contract storage
Chain.del(key);

Example:

// Store user balance
Chain.store('balance_' + userAddress, '1000000');

// Retrieve user balance
const balance = Chain.load('balance_' + userAddress);

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Account Query Functions

// Get account balance (returns string)
const balance = Chain.getBalance(address);

// Get account metadata
const metadata = Chain.getAccountMetadata(address, key);

// Get account assets
const asset = Chain.getAccountAsset(address, assetKey);

// Get account privileges
const privilege = Chain.getAccountPrivilege(address);

// Get contract properties
const props = Chain.getContractProperty(address);

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Transaction Functions

// Transfer ZETRIX coins (amount in ZETA)
Chain.payCoin(toAddress, amount, input, metadata);

// Transfer assets
Chain.payAsset(toAddress, issuer, code, amount, input, metadata);

// Issue new assets
Chain.issueAsset(code, amount);

Example:

// Transfer 1 ZETRIX (1000000 ZETA)
Chain.payCoin(recipientAddress, '1000000');

// Transfer custom asset
Chain.payAsset(recipientAddress, issuerAddress, 'MYTOKEN', '100');

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Contract Operations

// Call another contract
Chain.contractCall(contractAddress, asset, amount, input);

// Query another contract (read-only)
const result = Chain.contractQuery(contractAddress, input);

// Create/deploy a new contract
Chain.contractCreate(balance, type, code, input);

// Delegate call (execute code in current context)
Chain.delegateCall(contractAddress, input);

// Delegate query (query in current context)
const result = Chain.delegateQuery(contractAddress, input);

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Logging and Events

// Log transaction events (generates on-chain log)
Chain.tlog(topic, arg1, arg2, arg3, arg4, arg5);

Example:

// Log token transfer event
Chain.tlog('Transfer', senderAddress, receiverAddress, amount);

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Built-in Objects

// Current block information
const blockNumber = Chain.block.number;
const blockTimestamp = Chain.block.timestamp;

// Transaction information
const initiator = Chain.tx.initiator;
const sender = Chain.tx.sender;
const gasPrice = Chain.tx.gasPrice;
const txHash = Chain.tx.hash;
const feeLimit = Chain.tx.feeLimit;

// Message information
const msgInitiator = Chain.msg.initiator;
const msgSender = Chain.msg.sender;
const coinAmount = Chain.msg.coinAmount;
const asset = Chain.msg.asset;
const nonce = Chain.msg.nonce;
const operationIndex = Chain.msg.operationIndex;

// Current contract address
const contractAddr = Chain.thisAddress;

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Utils Object

The Utils object provides cryptographic and mathematical utilities.

256-bit Integer Operations

// Compare two 256-bit integers (returns 1, 0, or -1)
const cmp = Utils.int256Compare(x, y);

// Arithmetic operations (all return strings)
const sum = Utils.int256Add(x, y);
const diff = Utils.int256Sub(x, y);
const product = Utils.int256Mul(x, y);
const quotient = Utils.int256Div(x, y);
const remainder = Utils.int256Mod(x, y);

Example:

// Calculate total supply
const total = Utils.int256Add('1000000', '500000'); // "1500000"

// Check if balance is sufficient
if (Utils.int256Compare(balance, amount) >= 0) {
    // Sufficient balance
}

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64-bit Integer Operations

const cmp = Utils.int64Compare(x, y);
const sum = Utils.int64Add(x, y);
const diff = Utils.int64Sub(x, y);
const product = Utils.int64Mul(x, y);
const quotient = Utils.int64Div(x, y);
const remainder = Utils.int64Mod(x, y);

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Cryptographic Functions

// SHA-256 hashing (returns base16 encoded hash)
const hash = Utils.sha256(data, dataType);

// Verify ECDSA signature
const isValid = Utils.ecVerify(signedData, publicKey, blobData, blobDataType);

// Convert public key to address
const address = Utils.toAddress(publicKey);

Example:

// Hash message
const messageHash = Utils.sha256('Hello World', 1);

// Verify signature
if (Utils.ecVerify(signature, publicKey, message, 1)) {
    // Signature is valid
}

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Validation Functions

// Validate address format
const isValidAddr = Utils.addressCheck(address);

// Validate 64-bit string number
const isValid64 = Utils.stoI64Check(strNumber);

// Validate 256-bit string number
const isValid256 = Utils.stoI256Check(strNumber);

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Utility Functions

// Output log (trace level)
Utils.log('Debug info');

// Assert condition (throws if false)
Utils.assert(condition, 'Error message');

// Convert to base unit (multiply by 10^6)
const baseUnit = Utils.toBaseUnit(value);

// Convert hex to decimal
const decimal = Utils.hexToDec(strHex);

Example:

// Validate input
Utils.assert(Utils.addressCheck(recipient), 'Invalid recipient address');

// Convert 1 ZETRIX to ZETA
const microZTX = Utils.toBaseUnit('1'); // "1000000"

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