Introducing the Aestus Relay

Aestus Relay
4 min readDec 10, 2022

The Aestus MEV-Boost Relay is a neutral, non-censoring block relay for Ethereum proof-of-stake validators and block builders. We provide both Ethereum mainnet and Goerli block relays, available at We welcome all builders, validators, and relay monitors. This document explains our guiding principles and commitment to neutrality.

Mainnet MEV-Boost URL

Goerli MEV-Boost URL

Photo by Joshua Gaunt on Unsplash


The Aestus relay project developed out of conversations between members of the EthFinance and EthStaker communities who see the need to develop credibly neutral architecture for the Ethereum staking ecosystem. Aestus, the Latin root for estuary, refers to a sheltered body of water where fresh river water mixes with saline ocean water, creating a healthy environment for life to thrive. Likewise, a relay operates at the interface where transaction flow finally reaches validators; a place we hope to build a similarly healthy environment.

MEV returns are likely to remain an important source of profits for those participating in Ethereum PoS consensus. The MEV-Boost para-protocol has been developed by entities with financial interests in its usage, and the absence of community oversight or meta-governance by core developers is concerning. In-protocol PBS may address some of these concerns, however MEV, in some form, is probably here to stay.

For those currently staking, principled non-participation in the MEV ecosystem is of course an option, but this only creates additional long-term centralizing forces. And yet, for those that choose to participate, the lack of diversity and opaque relationships between relays, searchers, and builders operating around this dark forest make it difficult for stakers to decide which relays to use or trust.

The Aestus relay is MEV infrastructure which we offer to the community as a public good, free from any commercial interest and aligned to principles of credible neutrality:

Censorship Resistant

The Aestus relay will never censor or filter transactions

Ethereum block production faces a problem of censorship: currently a majority of blocks are sent through relays that enforce OFAC compliance, threatening the credible neutrality of Ethereum as a whole. We believe it is vital to operate and support relays that oppose censorship.


The Aestus relay will never exclude or promote specific types of MEV searcher strategy

While the argument may be made that some MEV strategies are harmful to the Ethereum ecosystem, we believe that a neutral relay should not place itself in a position to act as an arbiter of what separates “good” and “bad” MEV. In the long term, we support the mitigation of harmful MEV through research and development of technologies such as a shutterized beacon chain and Flashbots’ SUAVE.


The Aestus relay will never profit indirectly or directly from MEV

MEV-Boost relays require a high level of trust from both block builders and validators to properly carry out their duties without exploiting their trusted position for personal gain. To help build and support this trust, we commit to running the Aestus relay as a non-profit public good. Operating costs will be funded by contributions from team members and through grants.


The Aestus relay will never compete with or make exclusive relationships with builders and searchers

The vast majority of existing relays are run by entities who simultaneously run their own block builder and searcher and/or transaction submission RPC. This vertical integration leads to a potential conflict of interest and requires a higher degree of trust. We will not run our own builder, instead welcoming unaffiliated third-party builders. We commit to treating all builders equally, with no prioritized block validation or required whitelisting.

Open Source

The Aestus relay’s architecture and all modifications to existing projects will be published for all to see

For maximum transparency, all relay code run on our servers is available on our GitHub organization page. In addition, we have open sourced our Kubernetes configuration, which we hope will help others in establishing additional relays.


The Aestus relay is committed to these principles of neutrality, and hope to contribute to a healthy and diverse relay ecosystem. We welcome connections from all validators, block builders, and monitors. Please reach out with any questions or comments on Twitter @AestusRelay or via email.