.value Number Value of transaction. options.nonce Number Transaction nonce. options.gasPrice Number Gas price. The unit is 10^-18 NAS. options.gasLimit Number Transaction gas limit. options.contract Contract &lt;optional&gt; Example { chainID: 1, from: \"n1QZMXSZtW7BUerroSms4axNfyBGyFGkrh5\", to: \"n1SAeQRVn33bamxN4ehWUT7JGdxipwn8b17\", value: 10, nonce: 12, gasPrice: 1000000, gasLimit: 2000000 } Buffer Binary data type Type: TypedArray Example &lt;Buffer 5b ed 67 f9 9c b3 31 9e 0c 6f 6a 03 54 8b e3 c8 c5 2