Ethereum Compatibility
Kaia provides wrapped transaction types to support Ethereum compatibility. Ethereum transaction types in Kaia have the same attributes and RLP encoding schemes with Ethereum's design except for the single-byte type delimiter called EthereumTxTypeEnvelope. Therefore, users can successfully deploy transactions generated by Ethereum development tools on Kaia. The type delimiter is also omitted when users use eth namespace APIs, so they can use Kaia just as if they were using Ethereum. Using kaia namespace APIs, users can deploy and retrieve Ethereum formatted transactions as a type of Kaia transactions without getting confused with the existing Kaia transaction types.
EthereumTxTypeEnvelope
EthereumTxTypeEnvelope is a single-byte prefix for raw transactions that denotes Ethereum transaction types. Ethereum has adopted an extendable transaction type scheme from EIP-2718 and it uses a type numbering system that conflicts with Kaia's. To resolve the conflict between two different transaction type schemes, Kaia has introduced EthereumTxTypeEnvelope which allows for separation and expansion for future Ethereum transaction types.
EthereumTxTypeEnvelope is an additional type delimiter and used only for raw transactions and type numbering. It is not used for transaction hash or signature hash. For that purpose, EthereumTransactionType as defined in EIPs is used.
- EthereumTxTypeEnvelope:
0x78 - TxHashRLP : EthereumTransactionType || TransactionPayload
- RawTransaction : EthereumTxTypeEnvelope || EthereumTransactionType || TransactionPayload
TxTypeEthereumAccessList
TxTypeEthereumAccessList represents a type of Ethereum transaction specified in EIP-2930. This transactions type contains an access list, a list of addresses and storage keys that the transaction is supposed to access. Since this transaction type exists to support compatibility, it only works with EOAs associated with [AccountKeyLegacy]. EOAs associated with other account key types should use other transaction types such as TxTypeValueTransfer, TxTypeSmartContractExecution, and so on. This transaction type can create accounts, transfer tokens, deploy/execute smart contracts or a mix of the aforementioned.
Kaia networks can process this transaction type after the EthTxTypeCompatibleBlock
NOTE: This transaction type only supports the format of the Ethereum transaction type. Unlike EIP-2930, there are no benefits in terms of transaction fee from using access list.
Attributes
| Attribute | Type | Description |
|---|---|---|
| type | uint8 (Go) | The type of TxTypeEthereumAccessList that is a concatenation of EthereumTxTypeEnvelope and EthereumTransactionType. This must be 0x7801. |
| chainId | *big.Int (Go) | The destination chain ID. |
| nonce | uint64 (Go) | A value used to uniquely identify a sender’s transaction. If two transactions with the same nonce are generated by a sender, only one is executed. |
| gasPrice | *big.Int (Go) | A multiplier to get how much the sender will pay in tokens. The amount of tokens the sender will pay is calculated via gas * gasPrice. For example, the sender will pay 10 KAIA for a transaction fee if gas is 10 and gasPrice is 10^18. See [Unit of KAIA]. |
| gas | uint64 (Go) | The maximum amount of transaction fee the transaction is allowed to use. |
| to | *common.Address (Go) | The account address that will receive the transferred value. |
| value | *big.Int (Go) | The amount of KAIA in kei to be transferred. |
| data | []byte (Go) | Data attached to the transaction, used for transaction execution. |
| accessList | type.AccessList (Go) | A list of addresses and storage keys consisting of [](common.Address, []common.Hash). |
| v, r, s | *big.Int (Go) | The cryptographic signature generated by the sender to let the receiver obtain the sender's address. |
RLP Encoding for Signature
To make a signature for this transaction type, the RLP serialization proceeds as follows:
This type of transaction should be signed with London Signer
SigRLP = EthereumTransactionType || encode([chainId, nonce, gasPrice, gasLimit, to, value, data, accessList])SigHash = keccak256(SigRLP)Signature = sign(SigHash, <private key>)
RLP Encoding for SenderTxHash
To obtain SenderTxHash for this transaction type, the RLP serialization proceeds as follows:
SenderTxHashRLP = EthereumTransactionType || encode([chainId, nonce, gasPrice, gasLimit, to, value, data, accessList, v, r, s])SenderTxHash = keccak256(SenderTxHashRLP)Signature = sign(SenderTxHash, <private key>)
RLP Encoding for Transaction Hash
To make a transaction hash, the RLP serialization proceeds as follows:
TxHashRLP = EthereumTransactionType || encode([chainId, nonce, gasPrice, gasLimit, to, value, data, accessList, v, r, s])TxHash = keccak256(TxHashRLP)
Raw Transaction
RawTx = EthereumTxTypeEnvelope || EthereumTransactionType || encode([chainId, nonce, gasPrice, gasLimit, to, value, data, accessList, v, r, s])
RLP Encoding (Example)
The following shows the result of the RLP serialization and the transaction object:
TX(3a3ab67168de40b1f8a2141a70a4e2f551f90d7814b2fbcb3ac99ad8d8d0b641) Contract: false Chaind: 0x2 From: a94f5374fce5edbc8e2a8697c15331677e6ebf0b To: 7b65b75d204abed71587c9e519a89277766ee1d0 Nonce: 1234 GasPrice: 0x19 GasLimit 0xf4240 Value: 0xa Data: 0x31323334 AccessList: [{0000000000000000000000000000000000000001 [0000000000000000000000000000000000000000000000000000000000000000]}] V: 0x1 R: 0xbfc80a874c43b71b67c68fa5927d1443407f31aef4ec6369bbecdb76fc39b0c0 S: 0x193e62c1dd63905aee7073958675dcb45d78c716a9a286b54a496e82cb762f26 Hex: 7801f8a1028204d219830f4240947b65b75d204abed71587c9e519a89277766ee1d00a8431323334f838f7940000000000000000000000000000000000000001e1a0000000000000000000000000000000000000000000000000000000000000000001a0bfc80a874c43b71b67c68fa5927d1443407f31aef4ec6369bbecdb76fc39b0c0a0193e62c1dd63905aee7073958675dcb45d78c716a9a286b54a496e82cb762f26
RPC Output (Example)
The following shows a transaction object returned via JSON RPC.
The return of eth_getTransactionByHash
{ "blockHash": "0x7bd7e8a92ecaa5781a15a8b6fff589f8ac8a79325b517a1ba5d5f2f3d7af1b00", "blockNumber": "0x1c8f4b", "from": "0x5618e15ec2916bbe6cf2cce20ce31e61d6062cac", "gas": "0x174876e800", "gasPrice": "0x5d21dba00", "hash": "0x3f67e48c2090f560234f555cd4edf7853b6327aa9a6a795be1efe3f360dac118", "input": "0x1122", "nonce": "0x11", "to": "0x5dce87b5bfcde54023811b168dc97a9f10913957", "transactionIndex": "0x0", "value": "0x186a0", "type": "0x1", "accessList": [ { "address": "0x0000000000000000000000000000000000000001", "storageKeys": [ "0x0000000000000000000000000000000000000000000000000000000000000000" ] } ], "chainId": "0x2710", "v": "0x1", "r": "0xebb2d2144293c257e27aaa1d22156f322b0d2d7385257f186c117899d791f174", "s": "0x5cea970287c9f0f9754050a552c458c066d8f3b3e4639f561b22ce4cb7553ac0"}
The return of kaia_getTransactionByHash
{ "accessList": [ { "address": "0x0000000000000000000000000000000000000001", "storageKeys": [ "0x0000000000000000000000000000000000000000000000000000000000000000" ] } ], "blockHash": "0x7bd7e8a92ecaa5781a15a8b6fff589f8ac8a79325b517a1ba5d5f2f3d7af1b00", "blockNumber": "0x1c8f4b", "chainID": "0x2710", "from": "0x5618e15ec2916bbe6cf2cce20ce31e61d6062cac", "gas": "0x174876e800", "gasPrice": "0x5d21dba00", "hash": "0x3f67e48c2090f560234f555cd4edf7853b6327aa9a6a795be1efe3f360dac118", "input": "0x1122", "nonce": "0x11", "senderTxHash": "0x3f67e48c2090f560234f555cd4edf7853b6327aa9a6a795be1efe3f360dac118", "signatures": [ { "V": "0x1", "R": "0xebb2d2144293c257e27aaa1d22156f322b0d2d7385257f186c117899d791f174", "S": "0x5cea970287c9f0f9754050a552c458c066d8f3b3e4639f561b22ce4cb7553ac0" } ], "to": "0x5dce87b5bfcde54023811b168dc97a9f10913957", "transactionIndex": "0x0", "type": "TxTypeEthereumAccessList", "typeInt": 30721, "value": "0x186a0"}
TxTypeEthereumDynamicFee
TxTypeEthereumDynamicFee represents a type of Ethereum transaction specified in EIP-1559. This transaction type contains gasTipCap and gasFeeCap instead of gasPrice. Since this transaction type exists to support compatibility, it only works with EOAs associated with [AccountKeyLegacy]. EOAs associated with other account key types should use other transaction types such as TxTypeValueTransfer, TxTypeSmartContractExecution, and so on. This type of transaction can create accouns, transfer tokens, deploy/execute smart contracts, or a mix of the aforementioned.
NOTE: Kaia networks can process this transaction type after the EthTxTypeCompatibleBlock
Currently, this type of transaction only supports the format of the Ethereum transaction type. Unlike EIP-2930, there are no benefits in terms of transaction fees from using access list.
NOTE: Since Kaia has a fixed gas price, gasTipCap and gasFeeCap should take the gas price for the respective network, which is 250 Gkei at the time of writing.
Attributes
| Attribute | Type | Description |
|---|---|---|
| type | uint8 (Go) | The type of TxTypeEthereumDynamicFee that is a concatenation of EthereumTxTypeEnvelope and EthereumTransactionType. It must be 0x7802. |
| chainId | *big.Int (Go) | The destination chain ID. |
| nonce | uint64 (Go) | A value used to uniquely identify a sender’s transaction. If two transactions with the same nonce are generated by a sender, only one is executed. |
| gasTipCap | *big.Int (Go) | A multiplier to get how much the sender will pay in addition to baseFee. Since Kaia has a fixed gas price, gasTipCap and gasFeeCap should take the gas price for the respective network, which is 250 Gkei at the time of writing. |
| gasFeeCap | *big.Int (Go) | A multiplier to get how much the sender will pay in tokens. The amount of tokens the sender will pay is calculated via gas * gasFeeCap. Since Kaia has a fixed gas price, gasTipCap and gasFeeCap should take the gas price for the respective network, which is 250 Gkei at the time of writing. |
| gas | uint64 (Go) | The maximum amount of transaction fee the transaction is allowed to use. |
| to | *common.Address (Go) | The account address that will receive the transferred value. |
| value | *big.Int (Go) | The amount of KAIA in kei to be transferred. |
| data | []byte (Go) | Data attached to the transaction, used for transaction execution. |
| accessList | type.AccessList (Go) | A list of addresses and storage keys consisting of [](common.Address, []common.Hash). |
| v, r, s | *big.Int (Go) | The cryptographic signature generated by the sender to let the receiver obtain the sender's address. |
RLP Encoding for Signature
To make a signature for this transaction type, the RLP serialization proceeds as follows:
This type of transaction should be signed with London Signer
SigRLP = EthereumTransactionType || encode([chainId, nonce, gasTipCap, gasFeeCap, gasLimit, to, value, data, accessList])SigHash = keccak256(SigRLP)Signature = sign(SigHash, <private key>)
RLP Encoding for SenderTxHash
To obtain SenderTxHash for this transaction type, the RLP serialization proceeds as follows:
SenderTxHashRLP = EthereumTransactionType || encode([chainId, nonce, gasTipCap, gasFeeCap, gasLimit, to, value, data, accessList, v, r, s])SenderTxHash = keccak256(SenderTxHashRLP)Signature = sign(SenderTxHash, <private key>)
RLP Encoding for Transaction Hash
To obtain a transaction hash, the RLP serialization proceeds as follows:
TxHashRLP = EthereumTransactionType || encode([chainId, nonce, gasTipCap, gasFeeCap, gasLimit, to, value, data, accessList, v, r, s])TxHash = keccak256(TxHashRLP)
Raw Transaction
RawTx = EthereumTxTypeEnvelope || EthereumTransactionType || encode([chainId, nonce, gasTipCap, gasFeeCap, gasLimit, to, value, data, accessList, v, r, s])
RLP Encoding (Example)
The following shows the result of the RLP serialization and the transaction object:
TX(be74e122acf00c2f257e8698ecf01140b58b2880de3f24d0875730425eccb45a) Contract: false Chaind: 0x2 From: a94f5374fce5edbc8e2a8697c15331677e6ebf0b To: 7b65b75d204abed71587c9e519a89277766ee1d0 Nonce: 1234 GasTipCap: 0x19 GasFeeCap: 0x19 GasLimit 0xf4240 Value: 0xa Data: 0x31323334 AccessList: [{0000000000000000000000000000000000000001 [0000000000000000000000000000000000000000000000000000000000000000]}] V: 0x0 R: 0xca14aa0bada2da7ca1b143c16e2dd4a69f2a1e77ce54c7f6d440fe828a777f4f S: 0x117f0f78aed398b2995b5ee7c67ace25d52be3c72c1384c2aaa9683b351556 Hex: 7802f8a1028204d21919830f4240947b65b75d204abed71587c9e519a89277766ee1d00a8431323334f838f7940000000000000000000000000000000000000001e1a0000000000000000000000000000000000000000000000000000000000000000080a0ca14aa0bada2da7ca1b143c16e2dd4a69f2a1e77ce54c7f6d440fe828a777f4f9f117f0f78aed398b2995b5ee7c67ace25d52be3c72c1384c2aaa9683b351556
RPC Output (Example)
The following shows a transaction object returned via JSON RPC.
The return of eth_getTransactionByHash
{ "blockHash": "0x55792fe186e3d1515fe35a68c2c8d7977b2d7db184d80526f906c53222b77833", "blockNumber": "0x1c944d", "from": "0x5618e15ec2916bbe6cf2cce20ce31e61d6062cac", "gas": "0x174876e800", "gasPrice": "0x5d21dba00", "maxFeePerGas": "0x5d21dba00", "maxPriorityFeePerGas": "0x5d21dba00", "hash": "0x5db239963029ad9ef6c3331b10ae455638316e330b0efdae2cc1f8e86884e66e", "input": "0x1122", "nonce": "0x13", "to": "0xa0f1633f4c666d7fe5ba912bd5caf03d3655ac31", "transactionIndex": "0x0", "value": "0x186a0", "type": "0x2", "accessList": [ { "address": "0x0000000000000000000000000000000000000001", "storageKeys": [ "0x0000000000000000000000000000000000000000000000000000000000000000" ] } ], "chainId": "0x2710", "v": "0x1", "r": "0x27e007cbe79fd8cc9b89dd798bdd5aa62d038273bf006c7c3b40e13a938ab807", "s": "0x6209bb328855f02fa2671fecb41efd9f191b03ecab5e580227fa2a0674879384"}
The return of kaia_getTransactionByHash
{ "accessList": [ { "address": "0x0000000000000000000000000000000000000001", "storageKeys": [ "0x0000000000000000000000000000000000000000000000000000000000000000" ] } ], "blockHash": "0x55792fe186e3d1515fe35a68c2c8d7977b2d7db184d80526f906c53222b77833", "blockNumber": "0x1c944d", "chainId": "0x2710", "from": "0x5618e15ec2916bbe6cf2cce20ce31e61d6062cac", "gas": "0x174876e800", "hash": "0x5db239963029ad9ef6c3331b10ae455638316e330b0efdae2cc1f8e86884e66e", "input": "0x1122", "maxFeePerGas": "0x5d21dba00", "maxPriorityFeePerGas": "0x5d21dba00", "nonce": "0x13", "senderTxHash": "0x5db239963029ad9ef6c3331b10ae455638316e330b0efdae2cc1f8e86884e66e", "signatures": [ { "V": "0x1", "R": "0x27e007cbe79fd8cc9b89dd798bdd5aa62d038273bf006c7c3b40e13a938ab807", "S": "0x6209bb328855f02fa2671fecb41efd9f191b03ecab5e580227fa2a0674879384" } ], "to": "0xa0f1633f4c666d7fe5ba912bd5caf03d3655ac31", "transactionIndex": "0x0", "type": "TxTypeEthereumDynamicFee", "typeInt": 30722, "value": "0x186a0"}