Geth Sealer is a Geth extension that allows building blocks externally for faster iteration of building strategies
Most available block building tools are integrated into execution clients like Geth, forcing the user to restart the client and rebuild the mempool in order to roll out changes and test new code. This Geth Sealer eliminates that hassle, enabling a more efficient workflow for block building, speculative transaction execution, and backtesting.
The sealer takes private and global mempool transactions, constructs a block, and submits it to specified relay(s)—all external to Geth. This allows faster iteration for building and searching strategies.
After passing private transactions, the sealer can optionally fill the block from the public mempool up to the gas limit. While building a block, the sealer can also return call traces of the included transactions, allowing further inspection and analysis. These traces can be used to pre-filter transactions prior to block submission if desired: This is useful when a destination relay is known to apply filtering criteria to transactions.
Geth Sealer also enables speculative execution and backtesting. Speculative execution allows users to simulate outcomes of potential transactions prior to building and submitting a block, while backtesting can show how strategies would have performed with historical mainnet data—both crucial insights for optimizing one’s block building.