Wallet Operations Structures
The RawTxInfo object includes the following items:
| Parameter | Type | Description |
|---|---|---|
| tx_hex | string | UTXO only. The raw unsigned hex of a proposed transaction. |
| prev_txns | list | UTXO only. A list of standard InputTxns objects. |
| to | string | ETH/EVM only. A destination address to send the funds to. |
| value | string | ETH/EVM only. The amount of funds to be sent as a string with a 0x prefix, in wei units. |
| gas_limit | string | ETH/EVM only. The maximum gas to be used for sending the transaction, in gwei units. |
| pay_for_gas | object | Optional, ETH/EVM only. Used for EIP-1559 fee policy config. A standard PayForGas object. |
The InputTxns object includes the following items:
| Parameter | Type | Description |
|---|---|---|
| tx_hash | string | The transaction id of an unspent transaction from the same wallet output. |
| index | integer | The [output index(https://bitcoin.stackexchange.com/questions/100765/what-does-the-index-of-an-utxo-stand-for)] of this unspent transaction output. |
| script_pub_key | string | The scriptpubkey of this unspent transaction output. |
| amount | decimal | The value of this unspent transaction output. |
The PayForGas object includes the following items:
| Parameter | Type | Description |
|---|---|---|
| tx_type | string | ETH/EVM coins and tokens only. Options are Legacy or Eip1559. The type of transaction values being configured. |
| gas_price | decimal | Only used if tx_type is Legacy. Values are in Gwei. The maximium price per gas unit the user is willing to pay for the transaction. |
| max_fee_per_gas | decimal | Only used if tx_type is Eip1559. Values are in Gwei. The maximum amount to pay per unit of gas to get your transaction included in a block. |
| max_priority_fee_per_gas | decimal | Only used if tx_type is Eip1559. Values are in Gwei. This is paid directly to the miner, and can be set by the user to attract minimal delay in transaction confirmation. |
| min_wait_time | integer | Optional, only used if tx_type is Eip1559. Estimated minimum transaction wait time in mempool (in ms) for this priority level. |
| max_wait_time | integer | Optional, only used if tx_type is Eip1559. Estimated maximum transaction wait time in mempool (in ms) for this priority level. |
Eip1559 allows users to save on gas fees. To use this feature for a coin/token, its entry in your coins file must include fields for chain_id and max_eth_tx_type. To allow eip-1559 transactions, max_eth_tx_type should be set to 2. To find the chain_id for an [EVM network(https://blog.thirdweb.com/evm-compatible-blockchains-and-ethereum-virtual-machine/)], refer to chainlist.org. There is also a new gas_fee_estimator parameter in the coins file, which can be set to provider or simple.
By default, simple gas fee estimation suggests a fee based on fee history. If set gas_fee_estimator is set to provider, users must set the gas_api setting in their MM2.json file to source recommended fee values from third party providers Infura or Blocknative.
Use the start_eth_fee_estimator method to begin tracking the fee market for a coin (and its tokens). You can stop tracking the fee market with stop_eth_fee_estimator.
To set or view the current swap transaction fee policy, use the get_swap_transaction_fee_policy and set_swap_transaction_fee_policy methods.
For more information about EIP1559, refer to https://www.blocknative.com/blog/eip-1559-fees