MEV-Protect Pilot: Boost Validator Rewards and Promote Fairer MEV Distribution

By Eyal Markovich

In the MEV-Boost documentation, Flashbots explains the reasoning behind Proposer-Builder Separation (PBS):

“Separating the role of proposers from block builders promotes greater competition, decentralization, and censorship resistance for Ethereum.”

Unfortunately, exclusive orderflow (orderflow sent to a single builder) has had the opposite effect — reducing competition and increasing centralization.

Two years ago, bloXroute released the Proposer MEV-Protect feature, but no validators adopted it at launch. In recent months, as validator rewards have continued to decline, more validators have approached us about testing the feature.

In a nutshell, Proposer MEV Protect ensures validators are fairly rewarded for the blocks they propose. If a block pays less than 90% of its total value to the proposer, the relay will reject it unless the builder adds an additional fee. This safeguards validator revenue, discourages underpayment, and promotes healthier competition and alignment across the MEV ecosystem.

MEV-Protect Pilot

We are launching a pilot with leading validators to measure the impact of MEV-Protect. Our goal is to onboard enough validators to reach 15% stake before fully activating the program.

Based on modeling, we expect a 5–10% increase in Execution Layer rewards for participating validators. We also expect Ultrasound relay to support the MEV-Protect pilot.

MEV-Protect Data API Endpoints

We added two new data API endpoints to the bloXroute relays to help validators monitor the potential rewards and the effectiveness of the MEV-Protect program.

1. Summary Endpoint

Path:
blxr/v1/data/mevprotect/summary

Example URL:
https://bloxroute.max-profit.blxrbdn.com/blxr/v1/data/mevprotect/summary

Description:
This endpoint returns a summary for the last 24 hours (or less, depending on relay cache).

It shows, for each validator’s fee recipient:

Total block value
Total validator share
Total builder share
Additional revenue that would have been earned assuming 100% program success
Number and percentage of non-compliant blocks

Important: Compliance is measured at the block level.

A compliant block meets MEV-Protect payout rules for the proposer
A non-compliant block does not meet the rules (e.g., proposer payment < 90% of total block value)

Example Response:

{
  "start_slot": 12341059,
  "end_slot": 12343482,
  "start_time": "2025-08-11 12:53",
  "end_time": "2025-08-11 20:58",
  "duration": "8.0777 hours",
  "summary": [
    {
      "fee_recipient": "0x388c818ca8b9251b393131c08a736a67ccb19297",
      "total_block_value": "31.5958",
      "total_validator_value": "23.6326",
      "total_builder_value": "8.0695",
      "mev_protect_added_value": "2.6006",
      "total_slots": 502,
      "non_compliant_blocks": 394,
      "non_compliant_block_percentage": "78.49"
    },
    {
      "fee_recipient": "0xe688b84b23f322a994a53dbf8e15fa82cdb71127",
      "total_block_value": "9.1497",
      "total_validator_value": "7.2953",
      "total_builder_value": "1.9362",
      "mev_protect_added_value": "0.5866",
      "total_slots": 187,
      "non_compliant_blocks": 144,
      "non_compliant_block_percentage": "77.01"
    }
  ]
}

2. Slot Detail Endpoint

Path:
blxr/v1/data/mevprotect/slot

Example URL:
https://bloxroute.max-profit.blxrbdn.com/blxr/v1/data/mevprotect/slot

Query Parameters:

?slot=<slot> → Specific slot to retrieve
?limit=<limit> → Number of slots to return (default = 100)
?compliant=true → Return only compliant blocks
?compliant=false → Return only non-compliant blocks
?fee_recipient=<fee_recipient> → Filter on a single fee recipient

Description:
This endpoint provides detailed MEV-Protect compliance data for individual slots (or a range of slots).

It lets validators inspect:

Whether the block for that slot complied with MEV-Protect payout rules
The block’s total value and its breakdown between proposer and builder
The potential additional value the proposer could have earned under full compliance
The identity of the proposer and builder for that block

This data is useful for spot-checking compliance and understanding where value was lost to underpayment.

Example Response:

{
  "slot": 12341075,
  "block_number": 23117942,
  "parent_hash": "0xc5f7d44a5687f7f5b43a5f122b164c2abb16ba4c9c70a0a40b893d0ef8ea84b0",
  "block_hash": "0xceb680ab22c34f3eafbd6f63d66861918f3b04aa3078945f114396a976181969",
  "fee_recipient": "0x1135fa96848f34bff9d003f4c1699ae97418de29",
  "proposer_pubkey": "0x93359643a2454ab91720c44a49a40566faefd1de510cf4e2052a97f5d64a8c683cf3a7aed8f5730c88aeb54b256a912d",
  "builder_pubkey": "0x851b00b12f73770337fbd219b439aba7bd8e770dbdea16a3b0df030d971bc0d824d470d7868e5d93355f501bfe892947",
  "extra_data": "BuilderNet (Nethermind)",
  "compliant": false,
  "block_value_eth": "0.0209",
  "validator_value_eth": "0.0139",
  "builder_value_eth": "0.0070",
  "mev_protect_added_value_eth": "0.0023",
  "validator_value_percentage": "66.49"
}