RMC proposal: add ultra sound relay to "must use some" list

TLDR: This is a proposal addressed to the Relay Maintenance Committee to add the ultra sound relay to the “must use some” list.


We propose to add the ultra sound relay to the “must use some” (is_mandatory = True) relay list. Our understanding is that such inclusion is contingent on good performance. We argue below that the ultra sound relay has had continued excellent performance, from the perspective of both inclusion rate and stability.

inclusion rate

The ultra sound relay wins ~50% of its auctions—significantly more than any other relay. The rated.network screenshot below (time frame set to 1d) shows the inclusion rate for 8 Lido operators. Notice the size of the green bands corresponding to the ultra sound relay. For example, the ultra sound relay has roughly 5x the inclusion rate of the Flashbots relay (in yellow).

The high inclusion rate is due to various optimisations that reduce latency. For example, we run validation nodes on top-notch baremetal machines with AMD Epyc CPUs. The machines running validation nodes have 512GB of RAM, allowing to run Geth with the full Ethereum state in a RAM disk. We also have excellent connectivity to builders—the ultra sound relay enjoys roughly 90% of winning blockflow.

stability: The ultra sound relay has been running extremely stably on mainnet. We run the Flashbots relay codebase which has proven to be reliable. We have integrated devops best practices shared by Flashbots, and in some places tried to go above and beyond. We have not suffered any missed slot due to operational accidents on our side.

We have suffered only one partial outage of roughly 15 minutes due to an automatic update to the Flashbots relay version v1.15.1 which was buggy. This outage was quickly resolved thanks to a custom monitoring and alert system that called (and woke up!) our lead devops engineer Niclas. We have learned from this outage, and validators didn’t suffer from missed slots.


Thanks for the proposal, @JustinDrake.

I believe Ultrasound relay checks all the boxes for going on the must-include list and would be value-additive for Lido’s MEV revenue.


Here’s a 30-day inclusion rate (prepared by Mike Neuder) of the ultra sound relay. Surprisingly consistent around 50% :slight_smile:



Thanks for the excitement to get moving!

In general I think it makes sense to do this in a batch for all of the relays in the “allow list” (unless there’s a reason not to for specific relays, eg operational issues). 1 month sounds like a reasonable amount of time after which to commence any “bumping up”, so unless the rest of the relay maintenance committee has a differing opinion I would propose that we consider enacting this in ~two weeks!


Bumping this thread! (It’s been ~two months. :sweat_smile:)

Summary of how the 29 Lido operators stand relative to the ultra sound relay:

  • 23 operators (79%) have connected
  • 1 operator (Attestant) will connect after “must use some”
  • 1 operator (RockX) may connect after “must use some”
  • 1 operator (HashQuark) unlikely to connect without clarity from OFAC
  • 2 operators (Jump, Blockdaemon) won’t connect without clarity from OFAC
  • 1 operator (Figment) is considering whether or not to connect

Thanks for the bump! Given the MEV Boost issues following the relay vuln and bumpiness post Shapella this took a bit of a ride on the backburner :sweat:

Will align with RMC to get this reprioritized.


Doing a self-bump here. The RMC will consider:

  • Aestus Relay
  • Agnostic Relay
  • ultra sound relay

For inclusion into the “must use some” list this week.

Manifold will be considered once their transition to the new codebase is complete.