EIP-3074 (Batch) Transaction Invoker

An EIP-3074 based contract that can send one or more arbitrary transactions in the context of an Externally Owned Address (EOA), by using AUTH and AUTHCALL. The contract currently uses EIP-712-based messages for authentication.

This contract is a proof of concept, and is NOT audited. It's not recommended to use this in production environments.

Getting started

The contract is deployed on the Puxi testnet at 0x17C1244D6bBFD6cF5798035505cBdA305d388Bc1. Manually deploying this contract requires a custom version of Solidity, which you can find here: https://github.com/quilt/solidity/tree/eip-3074. Alternatively, you can use this forked version of Remix to compile and deploy the contract, or use the compiler that is included in this repo to compile it with Hardhat:

$ yarn compile

Signing a transaction

The contract currently uses EIP-712-based messages. You can use the following typed data object for creating the messages:

{
  "types": {
    "EIP712Domain": [
      { "name": "name", "type": "string" },
      { "name": "version", "type": "string" },
      { "name": "chainId", "type": "uint256" },
      { "name": "verifyingContract", "type": "address" }
    ],
    "Transaction": [
      { "name": "nonce", "type": "uint256" },
      { "name": "payload", "type": "TransactionPayload[]" }
    ],
    "TransactionPayload": [
      { "name": "to", "type": "address" },
      { "name": "value", "type": "uint256" },
      { "name": "gasLimit", "type": "uint256" },
      { "name": "data", "type": "bytes" }
    ]
  },
  "primaryType": "Transaction",
  "domain": {
    "name": "Transaction Invoker",
    "version": "0.1.0",
    "chainId": 224525,
    "verifyingContract": "0x17C1244D6bBFD6cF5798035505cBdA305d388Bc1"
  },
  "message": {
    "nonce": 0,
    "payload": [
      {
        "to": "0xeb2bdABFE67489072c01D3b51Ad0596974926dE7",
        "value": 0,
        "gasLimit": 200000,
        "data": "0xa9059cbb000000000000000000000000fffd6973e250e3db5471ede26c9f0ca7f8f708170000000000000000000000000000000000000000000000000000000000000001"
      }
    ]
  }
}

Simply replace the values in message with the actual values. If you're using your own version of the contract, make sure to also replace the values in the domain section.

You can use the script in scripts/sign.ts to sign a message using a private key. It uses the typed message in scripts/data/message.json. If you want to integrate this into your own UI, you can use my EIP-712 library for constructing compatible messages.

$ yarn sign PRIVATE_KEY

Using the contract

The contract has an invoke function which takes a Signature and Transaction. Signature is a struct that has the signature r, s, and v values (note that the v should be either 0 or 1). Transaction is a struct with the following values:

nonce (uint256) - The nonce of the transaction. You can get the expected value by reading nonces in the contract. It should increase by one for every transaction.
payload (TransactionPayload[]) - The transactions to send.

TransactionPayload looks like this:

to (address) - The address to send the transaction to.
value (uint256) - The amount of Ether to send. Note that in order to send Ether, you have to include it in the call to the invoker contract. AUTHCALL is currently not able to send Ether from an authenticated address.
gasLimit (uint256) - The maximum units of gas the transaction can use.
data (bytes) - The data to send to the contract.

If you are using the signing tool in scripts/sign.ts, it will generate Remix-compatible output based on the typed message. You can simply copy and paste the signature and transaction from there.

Automated testing

There are some automated tests for the contract in tests, which you can run using yarn test. Note that this requires Geth being available globally (e.g., in /usr/bin), which includes support for EIP-3074. The test script will spin up a private Geth network temporarily, run the tests, and remove the temporary network again.

$ yarn test

Contract ABI

The contract ABI for the invoker contract: