1. eth_estimateUserOperationGas

caution

This documentation is for using our Bundler API directly. If you are building with the Biconomy SDK you can follow the instructions on this page.

info

You can get your Bundler URL from the Biconomy Dashboard. This is the same endpoint URL used for all requests. All requests must follow the JSON RPC specifications.

You can test this endpoint on our Bundler Explorer

This endpoint is used to estimate the gas values for a UserOperation. Request constitutes given UserOperation optionally without gas limits and gas prices & returns the needed gas limits. The signature field is ignored by the wallet, so that the operation will not require user’s approval. It still requires putting a “semi-valid” signature (e.g. a signature in the right length)

Parameters

Body

Param	Type	Description	Required
method	string	Name of method in this case: eth_estimateUserOperationGas	Required
params	array	An array consisting of the Useroperation object and Bundler address	Required
id	string	id for request determined by client for JSON RPC requests	Required
jsonrpc	string	JSON RPC version in this case 2.0.0	Required

Request

{
    "method": "eth_estimateUserOperationGas",
    "params": [
        {
            "sender": "0x5A927A01a32cE02AF4B438b7848BceBc52C8Ea3e",
            "nonce": "0x1b",
            "initCode": "0x",
            "callData": "0x0000189a0000000000000000000000001758f42af7026fbbb559dc60ece0de3ef81f665e00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000002440d097c30000000000000000000000005a927a01a32ce02af4b438b7848bcebc52c8ea3e00000000000000000000000000000000000000000000000000000000",
            "signature": "0x00000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000001c5b32F37F5beA87BDD5374eB2aC54eA8e000000000000000000000000000000000000000000000000000000000000004181d4b4981670cb18f99f0b4a66446df1bf5b204d24cfcb659bf38ba27a4359b5711649ec2423c5e1247245eba2964679b6a1dbb85c992ae40b9b00c6935b02ff1b00000000000000000000000000000000000000000000000000000000000000",
            "paymasterAndData": "0x"
        },
        "0x5ff137d4b0fdcd49dca30c7cf57e578a026d2789"
    ],
    "id": 1697033406,
    "jsonrpc": "2.0"
}

Response

{
    "jsonrpc": "2.0",
    "id": 1697033406,
    "result": {
        "callGasLimit": 77217,
        "verificationGasLimit": 86895,
        "preVerificationGas": 772931,
        "validUntil": {
            "type": "BigNumber",
            "hex": "0xffffffffffff"
        },
        "validAfter": {
            "type": "BigNumber",
            "hex": "0x00"
        },
        "maxPriorityFeePerGas": "0",
        "maxFeePerGas": "100000000"
    }
}