go-ethereum/docs/interacting-with-geth/rpc/objects.md

title	description
Objects	Data structures used for RPC methods

The following are data structures which are used for various RPC methods.

Transaction call object

The transaction call object contains all the necessary parameters for executing an EVM contract method.

Field	Type	Bytes	Optional	Description
from	Address	20	Yes	Address the transaction is simulated to have been sent from. Defaults to first account in the local keystore or the 0x00..0 address if no local accounts are available.
to	Address	20	No	Address the transaction is sent to.
gas	Quantity	<8	Yes	Maximum gas allowance for the code execution to avoid infinite loops. Defaults to 2^63 or whatever value the node operator specified via --rpc.gascap.
gasPrice	Quantity	<32	Yes	Number of wei to simulate paying for each unit of gas during execution. Defaults to 1 gwei.
maxFeePerGas	Quantity	<32	Yes	Maximum fee per gas the transaction should pay in total. Relevant for type-2 transactions.
maxPriorityFeePerGas	Quantity	<32	Yes	Maximum tip per gas that's given directly to the miner. Relevant for type-2 transactions.
value	Quantity	<32	Yes	Amount of wei to simulate sending along with the transaction. Defaults to 0.
nonce	Quantity	<8	Yes	Nonce of sender account.
input	Binary	any	Yes	Binary data to send to the target contract. Generally the 4 byte hash of the method signature followed by the ABI encoded parameters. For details please see the Ethereum Contract ABI. This field was previously called data.
accessList	AccessList	any	Yes	A list of addresses and storage keys that the transaction plans to access. Used in non-legacy, i.e. type 1 and 2 transactions.
chainId	Quantity	<32	Yes	Transaction only valid on networks with this chain ID. Used in non-legacy, i.e. type 1 and 2 transactions.
maxFeePerBlobGas	Quantity	<32	Yes	Max fee per blob gas the transaction should pay in total. Relevant for blob transactions.
blobVersionedHashes	Array	any	Yes	Blob versioned hashes that can be accessed from EVM. They will be validated in case blobs also provided. Relevant for blob transactions.
blobs	Array	any	Yes	EIP-4844 Blobs.
commitments	Array	any	Yes	Commitments to EIP-4844 Blobs. They will be generated if only blobs are present and validated if both blobs and commitments are provided.
proofs	Array	any	Yes	Proofs for EIP-4844 Blobs. They must be provided along with commitments. Else they will be generated.

Example for a legacy transaction:

{
  "from": "0xd9c9cd5f6779558b6e0ed4e6acf6b1947e7fa1f3",
  "to": "0xebe8efa441b9302a0d7eaecc277c09d20d684540",
  "gas": "0x1bd7c",
  "data": "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"
}

Example for a type-1 transaction:

{
  "from": "0xd9c9cd5f6779558b6e0ed4e6acf6b1947e7fa1f3",
  "to":   "0xebe8efa441b9302a0d7eaecc277c09d20d684540",
  "gas":  "0x1bd7c",
  "data": "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",
  "chainId": "0x1",
  "accessList":  [
    {
      "address": "0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48",
      "storageKeys": ["0xda650992a54ccb05f924b3a73ba785211ba39a8912b6d270312f8e2c223fb9b1", "0x10d6a54a4754c8869d6886b5f5d7fbfa5b4
                  522237ea5c60d11bc4e7a1ff9390b"]
    }, {
      "address": "0xa2327a938febf5fec13bacfb16ae10ecbc4cbdcf",
      "storageKeys": []
    },
  ]
}

Example for a type-2 transaction:

{
  "from": "0xd9c9cd5f6779558b6e0ed4e6acf6b1947e7fa1f3",
  "to": "0xebe8efa441b9302a0d7eaecc277c09d20d684540",
  "gas": "0x1bd7c",
  "maxFeePerGas": "0x6b44b0285",
  "maxPriorityFeePerGas": "0x6b44b0285",
  "data": "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",
  "chainId": "0x1",
  "accessList": []
}

State override set

The state override set is an optional address-to-state mapping, used in eth_call and eth_simulateV1, where each entry specifies some state to be ephemerally overridden prior to executing the call. Each address maps to an object containing:

Field	Type	Bytes	Optional	Description
balance	Quantity	<32	Yes	Fake balance to set for the account before executing the call.
nonce	Quantity	<8	Yes	Fake nonce to set for the account before executing the call.
code	Binary	any	Yes	Fake EVM bytecode to inject into the account before executing the call.
state	Object	any	Yes	Fake key-value mapping to override all slots in the account storage before executing the call.
stateDiff	Object	any	Yes	Fake key-value mapping to override individual slots in the account storage before executing the call.
movePrecompileToAddress	address	20	Yes	Moves precompile to given address

The goal of the state override set is manyfold:

• It can be used by websites to reduce the amount of contract code needed to be deployed on chain. Code that simply returns internal state or does pre-defined validations can be kept off chain and fed to the node on-demand.
• It can be used for smart contract analysis by extending the code deployed on chain with custom methods and invoking them. This avoids having to download and reconstruct the entire state in a sandbox to run custom code against.
• It can be used to debug smart contracts in an already deployed large suite of contracts by selectively overriding some code or state and seeing how execution changes. Specialized tooling will probably be necessary.
• It can be used to override ecrecover precompile to spoof signatures

Example:

{
 "0xd9c9cd5f6779558b6e0ed4e6acf6b1947e7fa1f3": {
   "balance": "0xde0b6b3a7640000"
 },
 "0xebe8efa441b9302a0d7eaecc277c09d20d684540": {
   "code": "0x...",
   "state": {
	 ""
   }
 }
}

Block overrides

The fields of this object customize the block as part of which a call is simulated. This object can be passed to eth_call, eth_simulateV1 as well as debug_traceCall methods and contains the following fields:

Field	Type	Description
number	uint64	Block number.
prevRandao	uint256	The previous value of randomness beacon.
time	uint64	Block timestamp.
gasLimit	uint64	Gas limit.
feeRecipient	address	Fee recipient (also known as coinbase).
withdrawals	Withdrawals	Withdrawals made by validators.
baseFeePerGas	uint256	Base fee per unit of gas (see EIP-1559).
blobBaseFee	uint64	Base fee per unit of blob gas (see EIP-4844).

The object withdrawals is an array of withdrawal objects:

Field	Type	Description
index	uint64	index
validatorIndex	uint64	validator index
address	address	address
amount	uint64	amount