eth_simulateV1

Simulates transactions across multiple blocks. Allows you to test transactions with custom state and block parameters without submitting them to the network.

important

This method is only supported on Mainnet and Sepolia.

A maximum of 16 block state calls can be simulated in a single request. This is determined by assessing the blockStateCalls array of objects.

Parameters

• BLOCK STATE CALL OBJECT:
  • blockStateCalls: [required] Array of block, state, and call objects:
    • blockOverrides: [optional] Object to override block parameters:
      • baseFeePerGas: (string) Hexadecimal value for the base fee per gas for the block.
      • blobBaseFee: (string) Hexadecimal value for the base fee per unit of blob gas.
      • feeRecipient: (string) Address of the fee recipient for the block proposal.
      • gasLimit: (string) Hexadecimal value that represents the maximum amount of gas that transactions are allowed to consume.
      • number: (string) Hexadecimal block number.
      • prevRandao: (string) The previous value of randomness, which is used as a source of randomness for various protocol operations.
      • time: (string) Hexadecimal value representing the Unix epoch time in seconds.
    • stateOverrides: [optional] Object to override account states:
      • balance: (string) Hexadecimal value representing the account balance.
      • nonce: (string) Hexadecimal temporary nonce value for the call execution.
      • code: (string) Bytecode to inject into the account.
      • state: Object of key-value mappings to override all slots in the account storage before executing the call.
      • stateDiff: Object of key-value mappings to override individual slots in the account storage before executing the call.
      • movePrecompileToAddress: (string) Moves the precompile to the supplied address.
    • calls: [required] Array of transaction call objects:
      • from: [optional] 20 bytes - The address the transaction is sent from.
      • to: [optional] 20 bytes - The address the transaction is directed to.
      • gas: [optional] Hexadecimal value of the gas provided for the transaction execution.
      • gasPrice: [optional] Hexadecimal value of the gas price used for each paid gas.
      • maxPriorityFeePerGas: [optional] Maximum fee, in wei, the sender is willing to pay per gas above the base fee.
      • maxFeePerGas: [optional] Maximum total fee (base fee + priority fee), in wei, the sender is willing to pay per gas.
      • value: [optional] Hexadecimal value of the value sent with this transaction.
      • data: [optional] Hash of the method signature and encoded parameters. See the Ethereum contract ABI specification.
    • returnFullTransactionObjects: [optional] Boolean value which when true, returns full transaction objects, otherwise, just hashes are returned. The default is false.
    • traceTransfers: [optional] Boolean value which when true, adds ETH transfers as ERC20 transfer events to the logs, allowing you to trace value transfers. The default is false.
    • validation: [optional] Boolean value which when true, does all the validation that a normal EVM would do, except contract sender and signature checks. When false, eth_simulateV1 behaves like eth_call. The default is false.
  • blockParameter: (string) [optional] A hexadecimal block number, or one of the tags latest, earliest, pending or finalized. See the default block parameter.

Returns

An array of simulation result objects:

• baseFeePerGas: Hexadecimal value for the base fee per gas for the block.
• blobGasUsed: Hexadecimal value for the amount of blob gas used.
• calls: Array of call results:
  • returnData: Data returned for the call.
  • logs: Array of logs generated during the call.
    • address: Address of the contract that generated the log.
    • blockHash: Hash of the block.
    • blockNumber: Hexadecimal block number.
    • data: Non-indexed log parameters.
    • logIndex: Index of the log in the block.
    • removed: Whether the log was removed due to chain reorganization.
    • topics: Array of indexed log parameters.
    • transactionHash: Hash of the transaction.
    • transactionIndex: Index of the transaction in the block.
  • error: Object containing error information:
    • message: The error message.
    • code: The error status code.
    • data: Error-related information.
  • gasUsed: Hexadecimal value representing the amount of gas used.
  • status: Status indicating whether the transaction succeeded (0x1). 0x0 indicates that a transaction has failed.
• difficulty: A hexadecimal of the difficulty for this block.
• excessBlobGas: A hexadecimal of the excess blob gas.
• extraData: The "extra data" field of this block.
• gasLimit: Maximum gas allowed in this block.
• gasUsed: Total used gas by all transactions in this block.
• hash: Hash of the block. Null when the returned block is the pending block.
• logsBloom: The bloom filter for the logs of the block. Null when the returned block is the pending block.
• miner: Address of the beneficiary to whom the mining rewards were given.
• mixHash: Hexadecimal mix hash.
• nonce: Hash of the generated proof-of-work. Null when the returned block is the pending block.
• number: Block number. Null when the returned block is the pending block.
• parentBeaconBlockRoot: Parent beacon block root.
• parentHash: Hash of the parent block.
• receiptsRoot: The root of the receipts trie of the block. Also see Tries in Ethereum.
• sha3Uncles: The SHA3 of the uncles data in the block.
• size: A hexadecimal of the size of this block in bytes.
• stateRoot: The root of the final state trie of the block.
• timestamp: The unix timestamp for when the block was collated.
• totalDifficulty: A hexadecimal of the total difficulty of the chain until this block.
• transactions: (Array) An array of transaction objects, or 32 bytes transaction hashes depending on the last given parameter.
• transactionsRoot: The root of the transaction trie of the block.
• uncles: (Array) An array of uncle hashes.
• withdrawals: (Array) Withdrawal objects.
• withdrawalsRoot: Withdrawals trie root.

Example

Replace <YOUR-API-KEY> with an API key from your MetaMask Developer dashboard.

Request

curl

curl https://mainnet.infura.io/v3/<YOUR-API-KEY> \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "eth_simulateV1",
    "params": [
      {
        "blockStateCalls": [
          {
            "blockOverrides": {
              "baseFeePerGas": "0x9"
            },
            "stateOverrides": {
              "0xc000000000000000000000000000000000000000": {
                "balance": "0x4a817c800"
              }
            },
            "calls": [
              {
                "from": "0xc000000000000000000000000000000000000000",
                "to": "0xc000000000000000000000000000000000000001",
                "maxFeePerGas": "0xf",
                "value": "0x1"
              },
              {
                "from": "0xc000000000000000000000000000000000000000",
                "to": "0xc000000000000000000000000000000000000002",
                "maxFeePerGas": "0xf",
                "value": "0x1"
              }
            ]
          }
        ],
        "validation": true,
        "traceTransfers": true
      },
      "latest"
    ]
  }'

WSS

wscat -c wss://mainnet.infura.io/ws/v3/<YOUR-API-KEY> -x '{"jsonrpc":"2.0","id":1,"method":"eth_simulateV1","params":[{"blockStateCalls":[{"blockOverrides":{"baseFeePerGas":"0x9"},"stateOverrides":{"0xc000000000000000000000000000000000000000":{"balance":"0x4a817c800"}},"calls":[{"from":"0xc000000000000000000000000000000000000000","to":"0xc000000000000000000000000000000000000001","maxFeePerGas":"0xf","value":"0x1"},{"from":"0xc000000000000000000000000000000000000000","to":"0xc000000000000000000000000000000000000002","maxFeePerGas":"0xf","value":"0x1"}]}],"validation":true,"traceTransfers":true},"latest"]}'

Response

JSON

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": [
    {
      "baseFeePerGas": "0x9",
      "blobGasUsed": "0x0",
      "calls": [
        {
          "gasUsed": "0x5208",
          "logs": [
            {
              "address": "0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee",
              "blockHash": "0xc98388385b0dbfc15ad5c6a0f4b19f7abd94efb4618ced05e3eb320ee30b1e7f",
              "blockNumber": "0x1496e50",
              "data": "0x0000000000000000000000000000000000000000000000000000000000000001",
              "logIndex": "0x0",
              "removed": false,
              "topics": [
                "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
                "0x000000000000000000000000c000000000000000000000000000000000000000",
                "0x000000000000000000000000c000000000000000000000000000000000000001"
              ],
              "transactionHash": "0xe7217784e0c3f7b35d39303b1165046e9b7e8af9b9cf80d5d5f96c3163de8f51",
              "transactionIndex": "0x0"
            }
          ],
          "returnData": "0x",
          "status": "0x1"
        },
        {
          "gasUsed": "0x5208",
          "logs": [
            {
              "address": "0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee",
              "blockHash": "0xc98388385b0dbfc15ad5c6a0f4b19f7abd94efb4618ced05e3eb320ee30b1e7f",
              "blockNumber": "0x1496e50",
              "data": "0x0000000000000000000000000000000000000000000000000000000000000001",
              "logIndex": "0x1",
              "removed": false,
              "topics": [
                "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
                "0x000000000000000000000000c000000000000000000000000000000000000000",
                "0x000000000000000000000000c000000000000000000000000000000000000002"
              ],
              "transactionHash": "0xf0182201606ec03701ba3a07d965fabdb4b7d06b424f226ea7ec3581802fc6fa",
              "transactionIndex": "0x1"
            }
          ],
          "returnData": "0x",
          "status": "0x1"
        }
      ],
      "difficulty": "0x0",
      "excessBlobGas": "0x4920000",
      "extraData": "0x",
      "gasLimit": "0x1c9c380",
      "gasUsed": "0xa410",
      "hash": "0xc98388385b0dbfc15ad5c6a0f4b19f7abd94efb4618ced05e3eb320ee30b1e7f",
      "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
      "miner": "0x7e2a2fa2a064f693f0a55c5639476d913ff12d05",
      "mixHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
      "nonce": "0x0000000000000000",
      "number": "0x1496e50",
      "parentBeaconBlockRoot": "0x0000000000000000000000000000000000000000000000000000000000000000",
      "parentHash": "0xddd47e7383c8ced495e85e053f898d7a333feb0432fa9098306f6f563cde4984",
      "receiptsRoot": "0x75308898d571eafb5cd8cde8278bf5b3d13c5f6ec074926de3bb895b519264e1",
      "sha3Uncles": "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
      "size": "0x29c",
      "stateRoot": "0xd6da11fae4ab94ddba2c4c71206962f7c6eaec6e5fabf00f3f7540c4ed7ad8f1",
      "timestamp": "0x67803e64",
      "transactions": [
        "0xe7217784e0c3f7b35d39303b1165046e9b7e8af9b9cf80d5d5f96c3163de8f51",
        "0xf0182201606ec03701ba3a07d965fabdb4b7d06b424f226ea7ec3581802fc6fa"
      ],
      "transactionsRoot": "0x9bdb74f3ce41f5893a02a631e904ae0d21ae8c4e416786d8dbd9cb5c54f1dc0f",
      "uncles": [],
      "withdrawals": [],
      "withdrawalsRoot": "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421"
    }