Estimate Fees

Estimates the fees to be sent when calling outbound method on the contract. The fees to be paid are in the native token of the source chain. The fees can be calculated off-chain as well as on-chain, making SocketDL a smart contract first messaging protocol.

On-chain

The fees for relaying messages can be calculated on-chain by calling the getMinFees() method on Socket. The method can be inherited in your contract from the ISocket interface.

    interface ISocket {
        function getMinFees(
            uint256 minMsgGasLimit_,
            uint256 payloadSize_,
            bytes32 executionParams_,
            bytes32 transmissionParams_,
            uint32 remoteChainSlug_,
            address plug_
        ) external view returns (uint256 totalFees);
    }

Example

The SpeedRunDL example contract fetches the fee on-chain and checks if the fee sent from the user is correct.

    function _getMinimumFees(
        uint256 msgGasLimit_,
        uint32 _remoteChainSlug
    ) internal view returns (uint256) {
        return
            ISocket(socket).getMinFees(
                msgGasLimit_,
                _remoteChainSlug,
                address(this)
            );
    }

    function sendMessage() external payable {
        uint256 totalFees = _getMinimumFees(destGasLimit, remoteChainSlug);

        if (msg.value < totalFees) revert InsufficientFees();

        // ... remaining code
    }

Off-chain API

GET https://prod.dlapi.socket.tech/v1/estimate-min-fees

Header: x-api-key : 2Va1n3HzAS5XfXB8ELhX1aATJwzA1A72sNnJE1a0

Query Param	Description
srcPlug	Address of source Plug
srcChainSlug	Slug of source chain
dstChainSlug	Slug of destination chain
msgGasLimit	Gas limit required for executing the destination payload

Example Request

Estimating fees for sending a message from Polygon to Optimism

https://prod.dlapi.socket.tech/v1/estimate-min-fees?srcPlug=0x7b9ed5C43E87DAFB03211651d4FA41fEa1Eb9b3D&srcChainSlug=2999&dstChainSlug=10&msgGasLimit=100000

Note : Add the x-api-key header mentioned above in the request for authentication.

Response Parameters

Parameter	Description
result	Total fees to be paid in the native token of the source chain