Addition of tx preconfirmation functionality to API

[konradstrachan]

It would be desirable to be able to access limited preconfirmation data from Relays to support research we are doing on intent based architectures and hopefully level the playing field for as many fillers to compete in a risk managed manner leading to greater intent execution decentralisation.

Since all intent based protocols utilise FCFS auctions, fillers race to submit a filling bid earlier than others. Presently they this is done through a combination of protocol run execution insights (i.e. the protocol known an order has been signed because of API calls and thus can speculatively fill using this knowledge even before the tx reaches a mempool) or non-protocol aligned actors tailing public / private mempools directly prior to onchain confirmations.

We propose adding a new read-only API to the Relay (shown in green in the diagram below) that will accept a filter (e.g. a contract address possibly with a function selector) and return all the transactions currently in the best candidate block that meet these filter requirements.

This creates a mechanism that allows for a degree of limited probabilistic insight into future block composition without weakening in any way the proposer builder separation mechanisms.

Besides the previously noted advantage of decentralisation, if this functionality results in commercialisable datastreams consumed by Fillers (or other actors) it could be the foundation of an economic incentivisation mechanism for running Relays.

Along with this issue we are submitting an illustrative changeset that shows how we’d approach making this change at a high level. main...AneraLabs:mev-boost-relay:tx-inclusion-info-api

[konradstrachan]

Update : thanks to external discussions we realise that additional thought needs to go in to this. For now please disregard and I'll publish an update soon.