Block Engine

The following parties interacts with the block engine are:


  • SubscribePendingTransactions: subscribe to pending transactions from the relayer by sending a list containing accounts of interest. The block engine will forward any transactions that write-lock the accounts mentioned. Transactions have a timeout attached at which point they may get confirmed on-chain.
  • SendBundle: send a list of transactions
  • GetNextScheduledLeader, GetConnectedLeaders, GetTipAccounts: access information about connected validators and tip accounts.


  • SubscribePackets: receive transactions received by our system
  • SubscribeBundles: receive high-value and simulated bundles that contain MEV payment


  • SubscribeAccountsOfInterest: relayers receive a union of all of the accounts searchers are interested in.
  • StartExpiringPacketStream: relayers send packets that have