alloy-deadbeef

This crate allows to generate custom, vanity tx hash prefixes:

It brute-forces the correct hash iterating on gas_limit or value fields until it finds a matching prefix. You can read more about the implementation in this blog post.

Usage

cargo add alloy-deadbeef

You can use it as an as an alloy provider filler:

let provider = ProviderBuilder::new()
    .filler(DeadbeefFiller::new(
       "beef".to_string(),
       wallet.clone(),
    ))
    .wallet(wallet)
    .on_http(endpoint().parse()?);

All the transactions sent from this provider will land with a 0xbeef prefix. If you combine it with other fillers, it has to be the last one. Otherwise hash calculations will be invalid.

Alternatively, you can generate a tx object that, once submitted will have a matching hash prefix:

let tx = TransactionRequest {
    from: Some(account),
    to: Some(account.into()),
    value: Some(U256::ZERO),
    chain_id: Some(chain_id),
    nonce: Some(nonce),
    max_fee_per_gas: Some(gas_price * 110 / 100),
    max_priority_fee_per_gas: Some(GWEI_I),
    gas: Some(21000),
    ..Default::default()
};
let deadbeef = DeadbeefFiller::new("beef".to_string(), wallet.clone())?;
let prefixed_tx = deadbeef.prefixed_tx(tx.clone()).await?;

let provider = ProviderBuilder::new()
    .wallet(wallet)
    .on_http(endpoint().parse()?);

 let _ = provider
    .send_transaction(tx)
    .await?
    .get_receipt()
    .await?;

For prefixes up to 4 characters, it's possible to send nonpayable transactions because we're iterating on gas_limit instead of value. See this example for details on how to do it.

Alternatively, you can force a specific iteration mode like this:

let mut deadbeef = DeadbeefFiller::new("beef".to_string(), wallet)?;
deadbeef.set_iteration_mode(IterationMode::Value);

Processing time

The table shows the worst-case scenario processing times on MBP M2 with 12 CPU cores. Check out the blog post for more details.

Status

I'd appreciate feedback on how hash crunching speed can be improved. There's a benchmark to easily measure changes in performance:

cargo bench