How to perform Gasless swap automation manually using ether.js?

Created by Sourajyoti Gupta, Modified on Wed, 22 Nov, 2023 at 5:50 PM by Sourajyoti Gupta

To perfrom the GasLess sawp we need to generate the require arguments for executeMetaTransaction function

The function is configured with the following arguments.

address userAddress: The address of the user who signed the message data,

bytes memory functionSignature: encoded function data with required arguments.

you can create functionSignature using ethers or web3 library:

const functionSignature = contract.interface.encodeFunctionData("transfer", toAddress, amount])

For below three arguments you need to sign the EIP712 data and generate the R, S, and V

using the user address.

const domain = {
      name: "Contract name",
      version: "1",
      chainId: chainId,
      verifyingContract: contract.address,
    };

    const types = {
      MetaTransaction: [
        { name: "nonce", type: "uint256" },
        { name: "from", type: "address" },
        { name: "functionSignature", type: "bytes" },
      ],
    };

 const signature = await (await ethers.getSigner(accounts[0].address))._signTypedData(domain, types, value);
    const r = signature.slice(0, 66);
    const s = "0x".concat(signature.slice(66, 130));
    let : any = "0x".concat(signature.slice(130, 132));
    v = ethers.BigNumber.from(v).toNumber();

bytes32 sigR,
bytes32 sigS,
uint8 sigV

contract.executeMetaTransaction(userAddress,functionSignature,R,S,V)