Setting Up a MEV-Boost Relay Selection Strategy

MEV-Boost is an out-of-protocol service that allows Ethereum validators to access blocks built by professional searchers via a network of relays. A relay is a trusted intermediary that receives blocks from builders, verifies their validity, and forwards them to proposers. Your relay selection strategy directly impacts your proposer rewards and consensus safety. Choosing the right mix of relays involves evaluating their reputation, uptime, geographic distribution, and censorship policies. A poor strategy can lead to missed proposals or inclusion of invalid blocks.

The core decision is whether to use a single relay for simplicity or multiple relays for redundancy and better rewards. Using multiple relays is strongly recommended. You configure your validator client (like Teku, Prysm, or Lighthouse) with a list of relay URLs. The client will query all configured relays and select the block with the highest bid for your proposal slot. This setup provides fallback options if one relay is offline and increases your chance of receiving the most valuable block.

To implement this, you add the --builder-endpoint flag to your validator client's startup command, pointing to each relay's public endpoint. For example, a Lighthouse validator might use: --builder-endpoint https://0xac6e77dfe25ecd6110b8e780608cce0dab71fdd5ebea22a16c0205200f2f8e2e3ad3b71d3499c54ad14d6c21b41a37ae@boost-relay.flashbots.net. You must add this flag for every relay you wish to use. It's critical to use relays from different operators to avoid a single point of failure in your setup.

Evaluate relays based on key metrics: - Performance: Historical uptime and latency. - Censorship Resistance: Whether the relay filters transactions based on OFAC sanctions. - Transparency: Public metrics dashboards and open-source software. - Maximum Profit: The historical value of blocks delivered. Relays like the Flashbots Relay, Ultrasound Money Relay, and BloxRoute are common choices. Consult resources like MEV-Boost.org or Relayscan.io for live data and comparisons.

Your strategy must also consider ethical and regulatory alignment. Some relays, like the Flashbots Relay, apply OFAC compliance, excluding transactions from sanctioned addresses. Others are censorship-resistant. Running a mix of both types can help ensure network neutrality while managing potential regulatory risk. You can also configure a local block builder as a fallback to guarantee you can always produce a block, even if all external relays fail.

Regularly audit and update your relay list. Monitor your validator's performance using beacon chain explorers and tools like MEVWatch. A dynamic strategy that adapts to changes in relay performance, the emergence of new relays, or shifts in the regulatory landscape will serve you best in the long term. Proper relay selection is a foundational component of a professional, profitable, and resilient Ethereum staking operation.

A MEV-Boost relay is a trusted intermediary that connects block proposers (validators) with block builders. Its primary function is to receive blocks from builders, verify their validity, and forward the most profitable one to the proposer. Your selection strategy determines which relays your validator client will connect to, directly impacting your rewards and the censorship resistance of the blocks you propose. You will need your validator's BLS signing key and a basic understanding of your consensus client's configuration files.

To interact with MEV-Boost, you must run the MEV-Boost client software alongside your existing Ethereum validator setup. This client acts as middleware between your consensus client (like Lighthouse or Teku) and the external relay network. Ensure your system meets the requirements: a synced execution and consensus client, a funded validator with at least 32 ETH, and the ability to run an additional service on port 18550. The official client can be downloaded from the flashbots/mev-boost GitHub repository.

Relays differ in their submission policies, geographic location, and builder inclusion lists. Some relays, like the Flashbots relay, only accept blocks from a permissioned set of trusted builders to mitigate certain attacks. Others may be more permissive. Your strategy should consider this, as connecting to a diverse set of relays with different policies maximizes your access to the builder market and helps decentralize the flow of MEV. You can find a current list of active relays and their policies on community-maintained sites like mevboost.org.

The core of your strategy is defined in the MEV_BOOST_RELAYS environment variable or command-line flag when starting the mev-boost client. This is a comma-separated list of relay URLs. For example, a basic configuration might include: --relays https://0xac6e77dfe25ecd6110b8e780608cce0dab71fdd5ebea22a16c0205200f2f8e2e3ad3b71d3499c54ad14d6c21b41a37ae@boost-relay.flashbots.net,https://0x9000009807ed12c1f08bf4e81c6da3ba8e3fc3d953898ce0102433094e5f22f21102ec057841fcb81978ed1ea0fa8246@builder-relay-mainnet.blocknative.com. Each URL contains the relay's public key for authentication.

For advanced strategies, you can implement relay monitoring and failover logic. Tools like Prometheus metrics (exposed by mev-boost on port 18551) allow you to track performance metrics per relay, such as latency and bid delivery success rate. You can script automated processes to rotate your relay list based on this data or use orchestration tools to manage the service. The goal is to maintain high uptime and consistently receive the most valuable blocks without manual intervention.

Finally, test your configuration on a testnet before deploying on mainnet. Use the Goerli or Sepolia testnets to run through the entire flow: starting mev-boost, connecting your validator, and ensuring blocks are being proposed with payloads from external builders. This verifies your setup and helps you understand the logs and metrics you'll monitor in production. Remember that a well-considered relay strategy is a dynamic component of professional validator operation, requiring occasional review as the relay landscape evolves.

A MEV-Boost relay is a trusted intermediary that receives blocks from builders and forwards them to validators. Your selection strategy directly impacts your validator rewards and consensus-layer security. A poor strategy can lead to missed proposals, reduced profits, or exposure to malicious blocks. The core decision is choosing which relays to include in your relays array within the MEV-Boost client configuration. This is not a set-and-forget task; it requires ongoing evaluation based on performance data and network conditions.

Effective evaluation rests on three pillars: performance, reliability, and transparency. Performance is measured by the average block value a relay delivers, often tracked via dashboards like Relay Scan. Reliability refers to consistent uptime and low latency, ensuring your validator can receive a block in the narrow 1-second window. Transparency involves the relay's public commitment to censorship resistance, its operational policies, and whether it publishes its builder submissions and payments to a public data lake.

To build your strategy, start by aggregating data. Monitor the inclusion rate (percentage of your proposals that successfully get a block from the relay) and value comparison across relays over time. Tools like the Ethereum MEV Dashboard or running your own analysis with the mev-boost-relay monitoring client are essential. Do not rely solely on short-term averages; look for consistency across different times of day and network congestion levels.

Your final relay list should balance high-performing options with relays that prioritize credible neutrality. It is advisable to include at least one relay that operates under a minimum censorship resistance policy, such as refusing to exclude transactions based on OFAC sanctions. A diversified list mitigates the risk of a single relay's failure or malicious behavior. A sample configuration might prioritize two top-performing relays and include one or two smaller, ethically-aligned relays as backups.

Continuously test and iterate on your strategy. Use a testnet validator or a simulation environment to trial new relay configurations without risking mainnet penalties. Stay informed about changes in the relay landscape, such as new entrants, protocol upgrades like PBS (Proposer-Builder Separation), or shifts in builder dominance. Your strategy is a dynamic component of your validator's operation, requiring periodic review to align with the evolving MEV ecosystem.

MEV-Boost is a middleware service that allows Ethereum proof-of-stake validators to outsource block building to a competitive marketplace. By connecting to multiple relays, validators can receive blocks that include proposer payments from searchers and builders. Your relay selection strategy directly impacts your earnings and the censorship resistance of the network. This guide walks through the configuration process, from initial setup to advanced optimization.

The first step is to choose which relays to connect to. You should select a diverse set based on reputation, inclusion criteria, and performance. Key relays include those operated by Flashbots (boost-relay.flashbots.net), BloXroute (bloxroute.max-profit.blxrbdn.com), and the community-run Ultra Sound relay (relay.ultrasound.money). Each relay publishes its policies on filtering transactions, which is critical for compliance and ethical considerations. Avoid relying on a single relay to prevent centralization risks.

Configuration is done via your validator client's command-line flags or configuration file. For example, using the Prysm client, you would add flags like --http-mev-relay for each endpoint. A typical setup for a Lighthouse validator in the validator_definitions.yml file includes the suggested_fee_recipient and the builder_proposals flag set to true, with relays specified under builder_registration_config. Always use the latest stable release of your client and MEV-Boost software.

After configuration, monitor your relay performance. Use metrics from your validator client logs, the MEV-Boost dashboard, or tools like mevboost.pics to track metrics like received_blocks, submitted_bids, and won_bids. A healthy relay will consistently deliver valid block proposals. Watch for errors such as relay timeout or invalid header, which may indicate connectivity issues or that a relay is not serving your validator effectively.

To optimize earnings, consider implementing a dynamic relay selection strategy. This can involve scripts that periodically evaluate relay performance—comparing bid values and inclusion rates—and adjust your client's configuration accordingly. Some operators use services that automatically select the top-paying relay for each slot. Remember that frequent switching can have overhead; balance optimization with stability. Your primary goal is reliable block proposal, not just chasing the highest single bid.

Finally, stay informed about relay developments. The MEV ecosystem evolves rapidly, with new relays launching and policies updating. Follow relay operators' announcements on GitHub and social media. Participate in community discussions on forums like the Ethereum Research forum to understand the long-term implications of your relay choices on network health and decentralization. Your configuration is a key component in both your validator's profitability and the security of Ethereum.

MEV-Boost is a middleware service that allows Ethereum proof-of-stake validators to outsource block building to a competitive marketplace of specialized builders. The validator's role is to select which relays to connect to. A relay is a trusted intermediary that receives block proposals from builders and forwards them to validators. Your relay selection strategy directly impacts your validator's maximum extractable value (MEV) rewards and exposure to censorship or malicious behavior. A poor strategy can lead to missed rewards or, in extreme cases, slashing for proposing invalid blocks.

The core of your strategy is the --builder-proposal-flags configuration for your consensus client (e.g., Prysm, Lighthouse, Teku). This flag accepts a comma-separated list of relay URLs. A basic configuration might look like: --builder-proposal-flags="https://relay1.example.com,https://relay2.example.com". Your client will query all configured relays for a block proposal and select the one with the highest bid. However, a naive "connect to all public relays" approach is risky, as relay performance, uptime, and policies vary significantly.

A robust strategy involves programmatically managing your relay list. You should regularly audit relays based on key metrics: uptime (from services like mevboost.org), censorship resistance (does the relay filter transactions?), geographic latency, and fee structure. Many operators use scripts to fetch a curated list, such as the one maintained by ethstaker, and update their client configuration dynamically. This ensures you are always connected to high-performing, reputable relays.

For advanced automation, you can interact with the MEV-Boost API. Each relay exposes a standard /eth/v1/builder/header endpoint. You can write a script to ping multiple relays, compare the value field in the response (the bid in wei), and select the top N performers. Here's a simplified Python example using requests:

pythonCopy
import requests
relays = ["https://relay1.example.com", "https://relay2.example.com"]
best_bid = 0
best_relay = None
for relay in relays:
    try:
        resp = requests.get(f"{relay}/eth/v1/builder/header/...", timeout=2)
        bid = int(resp.json()['data']['value'])
        if bid > best_bid:
            best_bid = bid
            best_relay = relay
    except:
        continue
# Update client config with best_relay

Your final configuration must balance reward maximization with safety. It is recommended to use a diversified set of 3-5 relays from different entities to avoid single points of failure. Always exclude relays with a history of downtime or those that engage in transaction censorship. Monitor your validator's performance through beacon chain explorers and adjust your strategy based on real-world results. The MEV-Boost ecosystem evolves rapidly; maintaining an active, informed relay selection process is a continuous responsibility for professional validators.

Effective MEV-Boost operation requires continuous evaluation of your connected relays. Key performance indicators (KPIs) to monitor include: - Inclusion rate: The percentage of your proposed blocks that include a payload from that relay. - Payload value: The average priority fee and MEV reward delivered per block. - Latency and reliability: Frequent timeouts or missed bids indicate network or performance issues. - Censorship compliance: Monitoring if a relay is filtering transactions based on OFAC sanctions or other criteria, which may conflict with your validator's ethos.

To gather this data, you need to aggregate logs from your validator client (prysm, lighthouse, teku, etc.) and mev-boost client. Tools like Grafana with Prometheus can be configured to visualize metrics such as validator_proposed_total and builder_bid_value. Community dashboards and scripts, like those from ethstaker or Rated.Network, can provide a starting point. For a programmatic approach, you can parse the mev-boost logs or use the relay's public API endpoints (e.g., https://relay.example.com/relay/v1/data/bidtraces/proposer/{slot}) to audit historical performance.

Establish clear thresholds for rotation. For example, rotate away from a relay if its inclusion rate drops below 95% over 100 blocks, or if its average payload value is consistently in the bottom quartile of your relay set for a week. Censorship is a binary decision; many operators choose to rotate away from relays that filter OFAC-sanctioned transactions to support network neutrality. Automating this process with scripts minimizes manual overhead and ensures timely reactions.

Rotation is executed by updating your mev-boost service configuration. Using a system like Docker Compose or a systemd service file makes this straightforward. First, stop the service: sudo systemctl stop mev-boost. Then, edit the command-line arguments to replace the underperforming relay's URL with a new one from a trusted list like https://boost-relay.flashbots.net. Finally, restart the service: sudo systemctl start mev-boost. Your validator will begin using the new relay for the next epoch.

Maintain a diversified portfolio of 3-5 relays from different providers (e.g., Flashbots, BloxRoute, Titan, Ultrasound). This mitigates the risk of a single point of failure and ensures you capture value from different searcher markets. Periodically review the aggregate landscape for new, reputable relays and consider phasing out consistently poor performers. Your strategy should be a living document, updated as the MEV ecosystem evolves.

Your relay selection strategy directly impacts your validator's profitability and security. A balanced approach considers several factors: maximum extractable value (MEV) potential, censorship resistance, and relay reliability. Avoid relying on a single relay; diversify across multiple providers to mitigate the risk of downtime or malicious behavior. Regularly monitor metrics like proposal success rate, average block value, and latency using tools like mevboost.pics or your own beacon chain analysis. This data-driven approach allows you to make informed decisions rather than relying on static configurations.

For optimal performance, implement a dynamic selection strategy. A common method is to create a prioritized list in your mev-boost client configuration, ordering relays by a weighted score of their recent performance and attributes. You can automate this process using scripts that fetch the latest relay data and update your configuration. For example, a Python script could pull stats from a trusted API, filter out relays with poor uptime or known censorship, and generate a new YAML or TOML config file for mev-boost to use on its next restart. Remember to include reputable, non-censoring relays like agnostic-relay.net or ultrasound.money to ensure your validator contributes to a neutral chain.

Operational security is paramount. Always verify the authenticity of relay endpoints to prevent man-in-the-middle attacks. Use relays that support signed payloads to ensure the block headers you receive are valid. Keep your mev-boost client and associated software updated to patch vulnerabilities. Furthermore, understand the economic trade-offs: high-MEV relays may have higher latency or different filtering policies. Establish clear rules for your setup, such as a minimum relay uptime threshold (e.g., 99.5%) or a maximum acceptable latency (e.g., 500ms), and enforce them in your selection logic. By combining technical diligence with a principled, automated strategy, you can sustainably enhance your validator's rewards while upholding the integrity of the Ethereum network.