Transaction blocking by Ethereum app applied to Titan Builder blocks

Phylax and Titan Builder have begun enforcing app-specific transaction screening at the Ethereum block-building stage, filtering out transactions that violate safety rules set in advance by individual apps before they are included in blocks. Titan Builder accounted for roughly 53% of blocks validators accepted from external builders in a recent one-day tally by RelayScan, though that share reflects builder output rather than full Ethereum transaction coverage or universal app protection. Screening rules are defined by each app itself; Phylax cited a vault-style app capping a single withdrawal at 50% of held assets. The arrangement matters because it pushes risk controls upstream into block construction, potentially extending protections to users without relying on app-level enforcement alone. What to watch next is whether other builders and relays adopt similar pre-inclusion checks and how much of Ethereum's block flow ends up covered by app-defined rules.