Meta transaction (a.k.a. Gasless transactions) using ethers.js

Is there a way to implement a meta transaction using ethers.js library.

Consider a transaction to transfer 100 tokens from 0xAccountA to 0xAccountB. The transaction will be signed by 0xAccountA but the gas would be payed by some other 0xAccountC.

[joeb000]

@ricmoo just FYI I am working on extending ethers.js to add an intuitive way for Dapp devs to integrate meta transactions into their dapp with only a couple lines of code.

I am imagining something like this:

    const metaConfig = {
        relayerURL: "https://somerelayernode.com",
        metaType: "erc1776" // metamask Generalized MetaTransaction Contest winner: https://github.com/wighawag/singleton-1776-meta-transaction
    }
    const metaSigner = provider.getMetaSigner(metaConfig)
    const metaContract = new ethers.MetaContract(address, abi, metaSigner)

    // call it just like you would with a normal ethers contract
    let metaTx = await metaContract.someFunction(param1, param2)

Basically allow dapp devs using ethers to set their relayer and metaType in a config object and initialize a MetaSigner (extension of Signer) which instead of signing a transaction and POSTing to the Provider’s URL, it will sign a meta transaction (in the above example with signTypedData_v4) and send the signed meta transaction hex string to the relayerURL.

To pilot this concept I extended ethers.js with my own meta-ethers library and used my own simplified meta transaction schema. My experiments have gone very well, so I am now working on forking ethers.js base code to build this functionality into the native ethers.js source code itself. Will post back here when I have anything worthy of review/beta testing.

[ricmoo]

I have not actually used Meta-transactions yet, but all the necessary functions should certainly be available. I will be bugging the metatx cartel during DevCon5 to get caught up on the latest techniques. 😃