Manifold's builder is built different

Edited from a conversation I had with the dev in charge of our builder. A few very interesting elements here:

Our block builder doesn’t have an address. It’s a common misconception that there has to be one. We set the reward address of the block proposer as the coinbase of the block, so the block reward goes directly to that address. This is in contrast to other builders (Flashbots, Eden, bloXroute, etc.), who set their own builder address as the block’s coinbase and add a separate payment transaction at the end of the block.

Basically, we “enrich” the value of the block by adding transactions from our private transaction/bundle pool to the block and don’t take any cut for it. (For some future scenarios, we might consider taking a cut, in which case we would have an address where that cut would go, but at the moment we don’t.)

What’s more, we allow (and correctly validate) both approaches, unlike most other relays.

Here’s why I think this approach is better than the alternatives:

  • No superfluous transaction fees – By putting the transaction as payment at the end of the block, the gas for the transaction is essentially wasted. Our approach using the coinbase method wastes no fees (even if the recipient address is a smart contract!).

  • Transparency – When you look at a block built by Flashbots, you’ll usually see that the value of the last transaction is much higher than the gas tip reward of the block, raising the question of where the extra money came from. We, on the other hand, don’t subsidize blocks with our own money or the money from anyone else. That is, the block reward is simply the gas tips from the included transactions, and there aren’t any mystery funds/subsidies being distributed.