exchange.IO("api", “eth”, …)

The calling method of exchange.IO("api", "eth", ...) function is used to call the Ethereum RPC method.

The exchange.IO("api", "eth", ...) function returns the return value of the called RPC method. string, number, bool, object, array, null and all other types supported by the system

exchange.IO(k, blockChain, rpcMethod) exchange.IO(k, blockChain, rpcMethod, …args)

The k parameter is used to set the function of the exchange.IO() function, set to "api" indicates that the function is used to extend the call request. k true string The blockChain parameter is used to set the function of the exchange.IO() function, set to "eth" indicates that the function is used for RPC method calls on the Ethereum Network. blockChain true string The rpcMethod parameter is used to set the RPC method to be called by the exchange.IO() function. rpcMethod true string The arg parameter is used to specify the parameters of the RPC method to be called. There may be more than one arg parameter. The type and number of arg parameters depend on the RPC method specified by the rpcMethod parameter. arg false string, number, bool, object, array, function, null, and all other types supported by the system

function main() {
    // "owner" needs to be replaced with the specific wallet address
    // Parameter labels for the "latest" string position: 'latest', 'earliest' or 'pending', please refrer to https://eth.wiki/json-rpc/API#the-default-block-parameter
    // The return value ethBalance is a hexadecimal string: 0x9b19ce56113070
    var ethBalance = exchange.IO("api", "eth", "eth_getBalance", "owner", "latest")              

    // ETH has a precision unit of 1e18
    var ethDecimal = 18              

    // Because of the JavaScript language precision, it is necessary to use the system underlying package function BigInt, BigDecimal to process
    // Convert ethBalance to readable amount, 0x9b19ce56113070 to 0.043656995388076145
    Log(Number((BigDecimal(BigInt(ethBalance))/BigDecimal(Math.pow(10, ethDecimal))).toString()))
}

Check the balance of ETH in your wallet:

function mian() {
    // ETH has a precision unit of 1e18
    var ethDecimal = 18  

    // Number of transfers, readable amount e.g. 0.01 ETH
    var sendAmount = 0.01  

    // Due to the JavaScript language precision, it is necessary to use the system underlying encapsulated functions BigInt, BigDecimal to process, and to convert the readable amount to the data processed on the chain
    var toAmount = (BigDecimal(sendAmount)*BigDecimal(Math.pow(10, ethDecimal))).toFixed(0)
    
    // "toAddress" is the address of the recipient's ETH wallet at the time of the transfer, which needs to be filled in specifically, and toAmount is the number of transfers
    exchange.IO("api", "eth", "send", "toAddress", toAmount)
}

For ETH transfers, you can set the {gasPrice: 11, gasLimit: 111, nonce: 111} parameter, which is set on the last parameter of the exchange.IO() function, according to your specific needs. You can omit the nonce and use the system default, or leave gasLimit/gasPrice/nonce unset and use the system default value for all.

function toAmount(s, decimals) {
    return Number((BigDecimal(BigInt(s))/BigDecimal(Math.pow(10, decimals))).toString())
}

function main() {
    var gasPrice = exchange.IO("api", "eth", "eth_gasPrice")
    Log("gasPrice:", toAmount(gasPrice, 0))   // 5000000000 , in wei (5 gwei)
}

Query gasPrice:

function toAmount(s, decimals) {
    // The toAmount function can convert hex-encoded values to decimal values
    return Number((BigDecimal(BigInt(s))/BigDecimal(Math.pow(10, decimals))).toString())
}                

function main() {
    // Coding approve (authorization) method calls
    var data = exchange.IO("encode", "0x111111111117dC0aa78b770fA6A738034120C302", "approve", "0xe592427a0aece92de3edee1f18e0157c05861564", "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff")
    Log("data:", data)
    var gasPrice = exchange.IO("api", "eth", "eth_gasPrice")
    Log("gasPrice:", toAmount(gasPrice, 0))
    var obj = {
        "from" : "0x0xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",   // walletAddress
        "to"  : "0x111111111117dC0aa78b770fA6A738034120C302",
        "gasPrice" : gasPrice,
        "value" : "0x0",
        "data" : "0x" + data,
    }
    
    var gasLimit = exchange.IO("api", "eth", "eth_estimateGas", obj)
    Log("gasLimit:", toAmount(gasLimit, 0))
    Log("gas fee", toAmount(gasLimit, 0) * toAmount(gasPrice, 0) / 1e18)
}

Query eth_estimateGas:

The second parameter of the exchange.IO() function with "eth" can directly call the RPC methods available to the Ethereum node server.

{@fun BigDecimal}, {@fun BigInt}

exchange.IO("abi", ...) exchange.IO("encode", ...)