2. pm_sponsorUserOperation

caution

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

info

You can get your Paymaster 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 Paymaster Explorer

All paymaster URL's allow you to use both Sponsorship and Token Paymasters. To switch between paymasters you will simply change the Mode of a specific request. We will highlight both type of requests below.

This endpoint is responsible for calculating the paymasterAndData field, if applicable, for the given request.

The API receives a partial UserOp and an optional token address. From the mode parameter in request, it checks for the type of paymaster this request is for, and processes the request accordingly, as outlined below.

Sponsorship Paymaster

To determine whether a request can be sponsored by the Sponsorship Paymaster, only consider the partial UserOp object and the sponsorshipInfo. If the request cannot be sponsored, it would return "0x" as the paymasterAndData.

Token Paymaster

Consider both the partial UserOp and tokenAddress parameters in this case. If the tokenAddress is absent, an error will be thrown. If both are present, check for the TokenPaymaster flow and send the paymasterAndData response accordingly. If the tokenAddress is not supported, an error will also be thrown. Please see the error response at the end of this document.

Parameters

Body

Param	Type	Description	Required
method	string	Name of method in this case: pm_getFeeQuoteOrData	Required
params	array	An array consisting of the Useroperation object and Paymaster mode information	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

Params Array for Sponsorship requests

Index	Type	Description	Required
0	object	A partial userOperation object for the userOp that needs to be sponsored	Required
1	object	Mode specified as "SPONSORSHIP" as well as sposorship information which includes any webhook data and smart account information: name and version	Required

Params Array for ERC20 paymaster requests

Index	Type	Description	Required
0	object	A partial userOperation object for the userOp that needs to be sponsored	Required
1	object	Mode specified as "ERC20" as well as tokenInfo: a preferred token address and list of tokens to include	Required

note

"MODE" is mandatory for pm_sponsorUserOperation API,

• If "MODE" is SPONSORED, we check for request sponsorship. If request cannot be sponsored, we return 0x. This would mean users will pay for their gas fees.
• If "MODE" is ERC20, we return paymasterAndData for TokenPaymaster. This would mean that users will pay in there preferred ERC20 Tokens

1. Mode is SPONSORED :

POST Request

{
    "id": 1,
    "jsonrpc": "2.0",
    "method": "pm_sponsorUserOperation",
    "params": [
        {
            sender, // address
            nonce, // uint256
            initCode, // string
            callData, // string
            callGasLimit, // string
            verificationGasLimit, // string
            preVerificationGas, // string
            maxFeePerGas, // string
            maxPriorityFeePerGas, // string
        },
        {
            "mode": "SPONSORED",
						"calculateGasLimits": true,
						"expiryDuration": 300 //5mins
            "sponsorshipInfo": {
                "webhookData": {},
                "smartAccountInfo": {
                    "name": "BICONOMY",
                    "version": "1.0.0"
                }
            }
        }
    ]
}

Response

Success Response

{
    "jsonrpc": "2.0",
    "id": 1,
    "result": {
        "MODE": "SPONSORED",
        "paymasterAndData": "0xdc91ffb7c4b800d70410a79a5b503ae4391f67e40000000000000000000000007306ac7a32eb690232de81a9ffb44bb346026fab00000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000041e1f74852c31150f18ef4e472b748148f8ae031849032218b26170414a18c9f99516eb13a4a9bd35d1334194348cccee3d270b6e7bb400b39f0c8d645266ead601c00000000000000000000000000000000000000000000000000000000000000",
				"preVerificationGas": "75388",
				"verificationGasLimit": 57121,
				"callGasLimit": 108848
    }
}

2. Mode is ERC20 :

POST Request:

{
	"jsonrpc": "2.0",
	"id": 14,
	"method": "pm_sponsorUserOperation",
	"params": [
		{
			sender, // address
			nonce, // uint256
			initCode, // string
			callData, // string
			maxFeePerGas, // string
			maxPriorityFeePerGas, // string

			//optional fields
			callGasLimit, // string 
			verificationGasLimit, // string
			preVerificationGas, // string
		},
		{
			"calculateGasLimits": true,
			"mode": "ERC20",
			"tokenInfo": {
				"feeTokenAddress": "0xfd086bc7cd5c481dcc9c85ebe478a1c0b69fcbb9"
			}
		}
	]
}

Response:

{
    "jsonrpc": "2.0",
    "id": 1,
    "result": {
        "MODE": "SPONSORED",
        "paymasterAndData": "0xdc91ffb7c4b800d70410a79a5b503ae4391f67e40000000000000000000000007306ac7a32eb690232de81a9ffb44bb346026fab00000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000041e1f74852c31150f18ef4e472b748148f8ae031849032218b26170414a18c9f99516eb13a4a9bd35d1334194348cccee3d270b6e7bb400b39f0c8d645266ead601c00000000000000000000000000000000000000000000000000000000000000",
				"preVerificationGas": "75388",
				"verificationGasLimit": 57121,
				"callGasLimit": 108848
    }
}

2. Mode is ERC20 :

POST Request

{
    "id": 1,
    "jsonrpc": "2.0",
    "method": "pm_sponsorUserOperation",
    "params": [
        {
            sender, // address
            nonce, // uint256
            initCode, // string
            callData, // string
            maxFeePerGas, // string
            maxPriorityFeePerGas, // string

            //mandatory fields
            callGasLimit, // string 
            verificationGasLimit, // string
            preVerificationGas, // string
            
        },
        {
            "mode": "ERC20",
						"calculateGasLimits" : true,
						"expiryDuration": 300 //5mins
            "tokenInfo": {
                "feeTokenAddress": "0xbf22b04e250a5921ab4dc0d4ced6e391459e92d4"
            }
        }
    ],
}

Response

{
    "jsonrpc": "2.0",
    "id": 1,
    "result": {
        "MODE": "ERC20",
        "paymasterAndData": "0xdc91ffb7c4b800d70410a79a5b503ae4391f67e40000000000000000000000007306ac7a32eb690232de81a9ffb44bb346026fab00000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000041e1f74852c31150f18ef4e472b748148f8ae031849032218b26170414a18c9f99516eb13a4a9bd35d1334194348cccee3d270b6e7bb400b39f0c8d645266ead601c00000000000000000000000000000000000000000000000000000000000000",
				"preVerificationGas": "75388",
				"verificationGasLimit": 57121,
				"callGasLimit": 108848
    }
}

In response, the result field will contain paymasterAndData to be used in UserOp.