How to Implement a MEV-Boost Relay Strategy for Validators

MEV-Boost is a middleware service that allows Ethereum Proof-of-Stake validators to outsource block building to a competitive network of specialized builders via relays. By using MEV-Boost, validators can capture Maximal Extractable Value (MEV)—profits from reordering or including transactions—without running complex infrastructure themselves. This significantly increases validator rewards, with top-performing blocks often earning 2-5x the standard block reward. The core components are the validator client, the consensus client, the MEV-Boost software, and the chosen relays which connect validators to block builders.

To implement MEV-Boost, you must first configure your validator setup. This involves installing the mev-boost binary (or a client-integrated version) and updating your validator client's configuration. For example, using the Lighthouse validator client, you would add the --builder-proposals flag and point it to your local MEV-Boost instance with --suggested-fee-recipient set to your fee address. The MEV-Boost service itself is started with a command specifying which relays to connect to, such as mev-boost -relays https://0xrelay.url. It's critical to use multiple relays from different providers to maximize bid competition and censorship resistance.

Choosing which relays to use is a key strategic decision. Factors to evaluate include relay reputation, uptime history, censorship policies (some filter OFAC-sanctioned transactions), geographic distribution, and fee structures. Major relays include Flashbots Protect, BloXroute Max Profit, Ultrasound Money, and Agnostic Gnosis. A robust strategy involves configuring 3-5 trusted relays. You can monitor relay performance using dashboards like mevboost.org or relayscan.io, which track metrics like delivered payload value and latency. Avoid relying on a single relay to prevent missed revenue or centralization risks.

Once operational, your validator will receive execution payload headers from connected relays alongside local engine_getPayload calls. The consensus client selects the header with the highest value for the validator's fee recipient. The corresponding full block is only revealed upon a successful commitment, a process known as commit-reveal, which prevents theft. Validators should monitor logs for successful getHeader and getPayload calls. Key metrics to track are the proposer payment received (visible in logs as value) and the inclusion rate of MEV-Boost blocks versus locally built ones, aiming for near 100%.

Advanced strategies involve dynamic relay configuration and fallback logic. Tools like mev-boost-rs or orchestration scripts can help rotate relays based on performance or prune those with consistent failures. Consider running a fallback local builder like Flashbots' mev-geth fork or Reth to ensure block production if all relays fail. Remember that using MEV-Boost introduces external dependencies, so validator uptime and network connectivity are paramount. Always keep your mev-boost and client software updated to the latest stable releases for security patches and protocol compliance (e.g., Deneb/Cancun upgrades).

Implementing MEV-Boost is now considered essential for competitive validator rewards. By carefully selecting a diverse set of reputable relays, properly configuring your clients, and establishing monitoring, you can reliably capture MEV while contributing to a healthier, more decentralized ecosystem. For further details, consult the official MEV-Boost documentation and your specific consensus/validator client guides. The landscape evolves quickly, so staying informed about new relays, builder innovations, and protocol changes is part of an effective long-term strategy.

Implementing a MEV-Boost relay strategy requires a fully functional Ethereum validator node. This node consists of two core components: an execution client (like Geth, Nethermind, or Besu) and a consensus client (like Prysm, Lighthouse, or Teku). Both clients must be synchronized to the Ethereum mainnet and configured to communicate via the Engine API on localhost. Your validator must be actively attesting and proposing blocks. The primary prerequisite is running a consensus client that supports the external builder API, which is standard in all major clients post-Merge.

Your system must meet baseline hardware requirements to handle the additional data processing from MEV-Boost. We recommend a machine with at least 4 CPU cores, 16 GB of RAM, and a 2 TB NVMe SSD. A stable, high-bandwidth internet connection is critical, as MEV-Boost introduces new external network calls to relays during block proposal. Validators should also have a solid understanding of Linux system administration, including managing systemd services, monitoring logs, and configuring firewalls to allow traffic on necessary ports.

From a software perspective, you will need to install the MEV-Boost binary itself, available from the official flashbots/mev-boost repository. Ensure you download a release version compatible with your system architecture. You must also decide on a set of trusted relays to connect to, such as those operated by Flashbots, BloXroute, or Agnostic. Your choice impacts censorship resistance and maximum extractable value (MEV) potential. Finally, secure management of your validator's fee recipient address is essential, as this is where MEV rewards are sent.

MEV-Boost is a middleware that sits between an Ethereum validator client and the network. Its primary function is to outsource block production to a competitive marketplace of specialized block builders. Instead of constructing a block locally, the validator uses MEV-Boost to receive a complete, pre-built block from a relay. This block is typically more valuable because builders extract Maximal Extractable Value (MEV) from pending transactions—through arbitrage, liquidations, and other strategies—and share a portion of that profit with the validator proposing the block.

The architecture relies on three key actors: the validator (block proposer), the relay, and the builder. The relay is a trusted intermediary that receives blocks from builders, verifies their validity and payload, and forwards the most profitable one to the validator. Builders are specialized nodes that compete to create the most valuable block by including and ordering transactions. Validators configure their consensus client (like Lighthouse or Prysm) to connect to the MEV-Boost software, which then connects to one or more relays.

The operational flow for a validator begins when they are assigned to propose a block. Their MEV-Boost instance requests header bids from its connected relays. Each header contains a commitment to a full block body and the proposed fee (the bid) for the validator. MEV-Boost selects the header with the highest bid. The validator signs this header and returns it to the relay, at which point they receive the full block data. Finally, the validator proposes this block to the Ethereum network, earning the bid amount on top of the standard block reward.

Implementing a relay strategy is critical for validator profitability and security. Validators should connect to multiple reputable relays to ensure liveness and maximize bid competition. Key relays include Flashbots, BloxRoute, and Titan. It's essential to use relays that enforce payload transparency and cancellation conditions to protect against malicious or invalid blocks. Configuration involves setting the --builder and --relay flags in your consensus client or MEV-Boost software to the public endpoints provided by the relay operators.

While MEV-Boost significantly increases rewards, it introduces trust assumptions and centralization risks. The validator trusts the relay to deliver a valid block and the builder to honor the promised payment. To mitigate this, the protocol uses cryptographic commitments and slashing conditions. The ongoing development of PBS (Proposer-Builder Separation) aims to bring these mechanics directly into the Ethereum protocol, reducing reliance on external, trusted parties and creating a more robust and decentralized system for MEV distribution.

MEV-Boost is a middleware service that allows Ethereum Proof-of-Stake validators to access blocks built by a competitive network of builders via relays. Instead of constructing blocks locally, your validator client receives a complete, pre-built block from a relay just before the proposal deadline. This block includes the priority fee from user transactions and the MEV (Maximal Extractable Value) extracted by sophisticated searchers, resulting in significantly higher rewards than a standard block. The core components are your consensus client (e.g., Lighthouse, Prysm), your execution client (e.g., Geth, Nethermind), and the MEV-Boost software that sits between them.

To begin, you must install and configure the MEV-Boost client. Download the latest release for your operating system from the official MEV-Boost GitHub repository. The service is typically run via command line. A basic startup command looks like: ./mev-boost -relays https://0xac6e77dfe25ecd6110b8e780608cce0dab71fdd5ebea22a16c0205200f2f8e2e3ad3b71d3499c54ad14d6c21b41a37ae@boost-relay.flashbots.net. This example connects to Flashbots' relay. You should connect to multiple reputable relays for redundancy and better reward opportunities. Configure your consensus client to connect to MEV-Boost's local API, usually at http://localhost:18550.

Choosing relays is a critical security and profitability decision. Relays are trusted to deliver valid, executable blocks and distribute rewards honestly. Evaluate relays based on their uptime, censorship resistance policies, geographic distribution, and fee structure. Major options include the Flashbots Relay, Ultrasound Money Relay, Agnostic Relay, and BloxRoute Max Profit Relay. It is a best practice to configure at least 2-3 relays in your MEV-Boost client command using multiple -relay flags. This ensures your validator does not miss a proposal if one relay is temporarily unavailable.

Integration with your validator setup requires modifying your consensus client's configuration. For example, in Lighthouse, you add --builder http://localhost:18550 to your beacon node command. For Prysm, you use the flag --http-mev-relay http://localhost:18550. Your execution client must remain running and synced, as the relay's block payloads are ultimately executed against your local EL client. After restarting your consensus client with the new flags, monitor the logs for connections to MEV-Boost and for messages indicating successful registration with the relays.

Once operational, you can monitor performance using tools like the MEV-Boost UI (http://localhost:18550) or relay-specific dashboards such as Flashbots Relay Stats. Key metrics include your validator's registration status, the number of connected relays, and the value of the most recent proposed block. Rewards will appear as increased priority fees in your execution client's fee recipient address. It is crucial to keep MEV-Boost and all relay URLs updated, as the network evolves. Implementing MEV-Boost is now considered standard practice for maximizing validator rewards on Ethereum.

MEV-Boost is middleware that allows Ethereum proof-of-stake validators to outsource block building to a competitive marketplace. Instead of constructing a block locally, your validator client connects to a relay, which aggregates builder blocks and presents the most profitable one for you to sign. Your relay selection strategy directly impacts your rewards and the censorship resistance of the network. This guide covers how to analyze the trade-offs and configure your setup.

The core decision is which relays to trust. Each relay has a different set of connected builders and its own policies. Key factors to evaluate include: - Relay reputation and uptime (e.g., Flashbots, BloXroute, Agnostic) - Censorship resistance (does the relay filter transactions based on OFAC sanctions?) - Builder diversity (does the relay connect to many builders or a few dominant ones?) - Payment reliability (how and when are rewards delivered?). You configure your preferred relays in your mev-boost service startup command or configuration file.

A basic mev-boost service startup command might look like this, specifying multiple relays for redundancy:

codeCopy
mev-boost \
  -relay-check \
  -relays https://0xac6e77dfe25ecd6110b8e780608cce0dab71fdd5ebea22a16c0205200f2f8e2e3ad3b71d3499c54ad14d6c21b41a37ae@boost-relay.flashbots.net \
  -relays https://0x8b5d2e73e2a3a55c6c87b8b6eb92e0149a125c852751db1422fa951e42a09b82c142c3ea98d0d9930b056a3bc9896b8f@bloxroute.max-profit.blxrbdn.com \
  -relays https://0xa7ab7a996c8584251c8f925da3170bdfd6ebc75d50f5ddc4050a6fdc77f2a3b5fce2cc750d0865e06d4a27d0b5c34cc5@agnostic-relay.net

This configuration connects to three major relays, allowing mev-boost to solicit bids from builders across all of them for each slot.

To analyze performance, you must monitor your rewards and their source. Tools like mevboost.pics provide a public dashboard showing the market share of builders and relays. For personal analysis, your validator client logs will show which relay provided the winning block. Track metrics like: - Average block reward compared to the network average - The frequency of blocks you propose - The distribution of which builders and relays you are selecting. High variance is normal, but a prolonged underperformance may indicate a suboptimal relay set.

Your strategy should balance profit maximization with network health. Using only the highest-paying relay may centralize power and increase censorship risks. A recommended practice is to include at least one censorship-resistant relay (one that does not filter OFAC-sanctioned transactions) in your set. This ensures your validator contributes to credible neutrality. You can also implement a local builder fallback, where your own execution client builds a block if relay bids are too low or unavailable, though this requires more technical overhead.

Continuously review and update your strategy. The builder market evolves rapidly; new entrants emerge and relay policies can change. Join community discussions on forums like the EthStaker Discord or r/ethstaker to stay informed. By actively managing your MEV-Boost relay configuration, you optimize your rewards while supporting a decentralized and resilient block production ecosystem on Ethereum.

MEV-Boost is a middleware service that allows Ethereum Proof-of-Stake validators to outsource block building to a competitive market of specialized searchers and builders. By connecting to multiple relays, validators can access blocks containing Maximum Extractable Value (MEV)—profits from arbitrage, liquidations, and other on-chain opportunities—which significantly boosts their staking rewards. A validator's relay strategy directly impacts their earnings, the network's censorship resistance, and the overall health of the proposer-builder separation (PBS) ecosystem.

Your primary technical decision is which relays to configure in your mev-boost client. A robust strategy involves connecting to a diverse set of at least 3-5 reputable relays to ensure high block availability and bid competition. Key technical criteria include relay uptime (target >99%), geographic distribution to reduce latency, and the public attestation of their builder software. You must also verify a relay's compliance with OFAC sanctions lists; while compliant relays are common, including at least one non-compliant or "censorship-resistant" relay is a critical practice for network health.

Implementation involves configuring your validator client (e.g., Lighthouse, Prysm) with the --builder flag and pointing your mev-boost instance to your chosen relay endpoints. A sample command to run mev-boost might look like: mev-boost -relays https://0xrelay1.com,https://0xrelay2.com. It is essential to monitor metrics like getHeader latency, bid values received, and missed slot rates. Tools like Grafana dashboards for your execution and consensus clients should integrate MEV-Boost metrics to provide a complete performance picture.

Ethical considerations extend beyond pure profit. By deliberately selecting a relay set that includes builders with fair transaction ordering policies and those that resist transaction censorship, you contribute to Ethereum's neutrality and resilience. The community-driven Relay Monitor (https://www.relayscan.io) provides transparency into relay performance, builder market share, and censorship statistics, which should inform your ongoing strategy. Diversifying your relay set dilutes the influence of any single dominant builder or relay operator.

Your strategy must also account for validator responsibilities. You remain accountable for the blocks you propose, even if they are built by a third party. This includes understanding the potential negative externalities of certain MEV extraction methods, like time-bandit attacks or chain reorganizations. Engaging with the relay and builder ecosystem through forums and research, such as the Flashbots forum, helps validators stay informed on best practices and emerging risks in this evolving landscape.

Implementing a MEV-Boost relay strategy is a critical step for modern Ethereum validators. By connecting to multiple trusted relays like Flashbots, BloXroute, and Titan, you maximize your chances of receiving high-value blocks while distributing trust. This setup directly increases your validator's profitability through priority fees and MEV rewards, which are paid directly to your fee recipient address. Remember, your validator's duties remain unchanged; the consensus and execution clients simply receive block proposals from an external source.

To ensure long-term reliability and performance, establish a monitoring routine. Track key metrics such as your validator's inclusion rate, the frequency of empty proposals, and the average value of rewards from each connected relay. Tools like Grafana dashboards or the beacon chain explorer on Beaconcha.in are essential for this. Regularly review the health and reputation of your chosen relays, as the relay landscape evolves. Staying informed through channels like the EthStaker Discord or the Flashbots Discord is recommended for updates on new relays or protocol changes.

The next technical frontier is preparing for Proposer-Builder Separation (PBS). While MEV-Boost is an interim solution, full PBS will be a core protocol feature. Familiarize yourself with the concepts of builders and the crList. You can begin testing on Holesky testnet by configuring your validator with a builder_proposals flag if your client supports it. Exploring the code for relay APIs or builder software on GitHub can provide deeper insight into the system's mechanics.

Finally, consider your role in the ecosystem's health. Choosing relays that practice transparent filtering and contribute to mev-boost-relay-monitor helps combat malicious MEV. You can further contribute by running a block explorer for your local network or participating in community governance discussions about PBS design. Your implementation is now complete, but ongoing engagement ensures you continue to validate effectively and ethically as Ethereum evolves.