eth_estimateUserOperationGas

Tip

This method will not revert if the signature field in the user operation fails. However, most account implementations require the signature to be well formed, which usually means it must have the correct length.

For SimpleAccount, you can use the following dummy signature to put in the signature field during gas estimation:

0xfffffffffffffffffffffffffffffff0000000000000000000000000000000007aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa1c

This method simulates the user operation and estimates the appropriate gas limits for it.

If the operation is not successful, it will return an error.

EntryPoint v0.7

Request

{
  "jsonrpc": "2.0",
  "method": "eth_estimateUserOperationGas",
  "params": [
    {
      "sender": "0x5a6b47F4131bf1feAFA56A05573314BcF44C9149",
      "nonce": "0x845adb2c711129d4f3966735ed98a9f09fc4ce5700000000000000000000",
      "factory": "0xd703aaE79538628d27099B8c4f621bE4CCd142d5",
      "factoryData": "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",
      "callData": "0xe9ae5c5300000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000003400000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
      "callGasLimit": "0x0",
      "verificationGasLimit": "0x0",
      "preVerificationGas": "0x0",
      "maxFeePerGas": "0x7a5cf70d5",
      "maxPriorityFeePerGas": "0x3b9aca00",
      "paymaster": null,
      "paymasterVerificationGasLimit": null,
      "paymasterPostOpGasLimit": null,
      "paymasterData": null,
      "signature": "0xfffffffffffffffffffffffffffffff0000000000000000000000000000000007aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa1c",
    },
    "0x0000000071727De22E5E9d8BAf0edAc6f37da032"
  ],
  "id": 1
}

Response

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "preVerificationGas": "0xd3e3",
    "verificationGasLimit": "0x60b01",
    "callGasLimit": "0x13880",
    "paymasterVerificationGasLimit": "0x0",
    "paymasterPostOpGasLimit": "0x0"
  }
}

EntryPoint v0.6

Request

{
  "jsonrpc": "2.0",
  "method": "eth_estimateUserOperationGas",
  "params": [
    {
      "sender":"0xb341FEAFaF71b09089d03B7D114599f8F491EE45",
      "nonce":"0x0",
      "initCode":"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",
      "callData":"0x5194544700000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000008000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
      "callGasLimit":"0x0",
      "verificationGasLimit":"0x0",
      "preVerificationGas":"0x0",
      "maxPriorityFeePerGas":"0x3b9aca00",
      "maxFeePerGas":"0x7a5cf70d5",
      "paymasterAndData":"0x",
      "signature":"0x00000000fffffffffffffffffffffffffffffff0000000000000000000000000000000007aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa1c"
    },
    "0x5FF137D4b0FDCD49DcA30c7CF57E578a026d2789"
  ],
  "id": 1
}

Response

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "preVerificationGas": "0xdf55",
    "verificationGas": "0x52503",
    "verificationGasLimit": "0x52503",
    "callGasLimit": "0x13880"
  }
}

Using state overrides

You can use state overrides to simulate the user operation with a different state the same way you would with eth_call by including an optional third parameter. This is supported for both EntryPoint v0.6 and v0.7.

{
  "jsonrpc": "2.0",
  "method": "eth_estimateUserOperationGas",
  "params": [
    {
      "sender": "0xa203fDb8bC335F86016F635b85389B62B189E417",
      "nonce": "0x35bf2a054f92f3730b87582ef223c8d663f9eb01158154750000000000000000",
      "initCode": "0x",
      "callData": "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",
      "callGasLimit": "0x115b5c0",
      "verificationGasLimit": "0x249f0",
      "preVerificationGas": "0xeb11",
      "maxPriorityFeePerGas": "0x12a05f200",
      "maxFeePerGas": "0x5b08082fa",
      "paymasterAndData": "0x",
      "signature": "0xa6cc6589c8bd561cfd68d7b6b0757ef6f208e7438782939938498eee7d703260137856c840c491b3d415956265e81bf5c2184a725be2abfc365f7536b6af525e1c"
    },
    "0x5FF137D4b0FDCD49DcA30c7CF57E578a026d2789",
    {
      "0xd9c9cd5f6779558b6e0ed4e6acf6b1947e7fa1f3": {
        "balance": "0xde0b6b3a7640000"
      },
      "0xebe8efa441b9302a0d7eaecc277c09d20d684540": {
        "stateDiff": {
          "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80": "0x21"
        }
      }
    }
  ],
  "id": 1
}