blunt-instruments/MevWallet

MevWallet

MevWallet is a smart contract wallet that allows the user to capture MEV from Searchers, or create MEV on purpose.

This repo contains the solidity contracts in contracts/, deployment tooling in script/, and a Rust library for interacting with the contracts in src/.

THIS IS UNAUDITED CODE. USE AT YOUR OWN RISK

Wait what?

MevWallet is a smart contract wallet that allows the user to capture MEV from Searchers, or create MEV on purpose.

Ok yeah I heard you the first time, what does that mean?

User transactions pay fees, and may generate MEV. Searchers take the MEV from the user, and pay it to block proposers. This means that users are effectively paying block creators twice. Once via MEV, and once via the regular transaction fee.

MevWallet changes this relationship. Instead of paying block proposers via tx fees, users make transactions via the MevWallet. These transaction pay no tx fee. Instead, MevWallet transactions create MEV, and allow Searchers to pay tx fees on the user's behalf. This allows users to more effectively and efficiently price their transactions.

It also allows one more (really cool thing). It lets the user give the Searcher negative MEV. This means that the Searcher's bundle must pay the user for the right to broadcast the transaction. If the user is creating a large amount of MEV, they can force the Searcher to give them a cut of that MEV. The user gets to use this to cover their tx fees (cool!) and potentially end up paying less than 0 tx fees (coooler!).

Addresses

MevWeth: 0x00000000008C43efC014746c230049e330039Cb3
MevWalletV1 Implementation: 0x0000000000c08718718B974D644B098C19bd0064
MevWalletV1 ProxyFactory: 0x9248B5e672e1880af34068C0FaE18D30c26D05Fb

Didn't bother to grind an address for the proxy factory :)

How do I integrate it?

This repo has a Rust library for working with MevTxns. I'm also publishing a typescript library using ethers.js.

Use MevTxBuilder to build a txn:

let mev_tx: MevTx = MevTxBuilder::new()
  .from(&wallet_contract)
  .to(weth_address)
  .call(
    // WOW! you can use any `abigen!` generated call here!
    // (you can also you `.data(some_bytes)` to set the raw calldata
    ierc20::TransferCall {
      recipient,
      amount,
    }
  )
  .tip(1_000_000_000)
  .populate()
  .await?
  .build();
let signed_mev_tx = mev_tx.sign(wallet_address, signer).await?;

// You can convert from an ether-rs tx too!
// Middleware is required to resolve typed tx ENS name. This can often be a
// dummy middleware.
let typed_tx = weth.transfer(recipient, amount);
let signed_mev_tx = MevTxBuilder::from_typed_tx(&wallet_contract, typed_tx)
  .await?
  .nonce(5)
  // adding a signer signs the mev tx when it's built :)
  .with_signer(signer)
  // Defaults to the signer's chain_id
  .with_chain_id(31337)
  .populate()
  .await?
  .build(wallet_address)
  .await?;

Searchers should can use any middleware to send a MevTx:

let signed_mev_tx = serde_json::from_str(a_serialized_tx)?;

// `into_call` converts into a normal `ContractCall` wrapping the MevTx
// it sets value to the mev_tx_value, and
let pending = signed_mev_tx
  .into_call(arc_middleware.clone())
  // modify gas or w/e here :)
  // it is STRONGLY ADVISED that you use `.call()` to simulate
  // as we do not currently check the code at the wallet address
  .send()
  .await?;

You can also use this lib to deploy a new proxy contract:

// set owner to msg.sender
let my_wallet = MevWallet::new_proxy(middleware, salt).await?;

// set owner to an arbitrary address
let my_wallet = MevWallet::new_proxy(middleware, salt, owner_address).await?;

However, if doing it manually might be easier to use forge

forge script --broadcast $FORGE_SIGNER_INFO DeployProxyV0 --sig "run(bytes32)" $SALT -vvvvvv

MevTx Layout

MevTxns are very similar to normal txns, and are signed with EIP712.

to -- target address for the call.
data -- data for the call.
value -- value that should be passed in the call.
delegate -- true for delegatecall (but be careful!). Must be false if value is non-0
tip -- MEV created by the tx, in wei, can be negative
maxBaseFee -- call should not be executed above this basefee (may be 0, for no max)
deadline -- call should not be executed after this timestamp (may be 0, for no deadline)
nonce -- nonce for the MevTx, as set in MevWallet state

Repo Setup

$ git submodule update --init --recursive

Running Tests

Integrations tests are a bit funky right now. Run ./devenv.sh to start an anvil instance. Then run cargo test in another terminal. Use ctrl+C to exist the anvil instance when necessary.

Regenerating contract bindings.

It is NOT RECOMMENDED that you make contract changes. If you must, make sure to run ./bind.sh to generate the rust bindings.

Deploying MevWallet

If working on chain with a MevWeth deployment, use these scripts (including your RPC and signer details):

# deploy the implementation to a new chain
forge script DeployImplV0
# deploy the proxy factory to a new chain
forge script DeployFactoryV0
# deploy a new proxy wallet
forge script DeployProxyV0.sol --sig "run(bytes32)" $YOUR_SALT_BYTES32

If working on a fresh anvil instance or a chain without MevWeth, follow the MevWeth deployment instructions. Then deploy MevWallet as above :)

blunt-instruments / MevWallet