The ethical block builder for PulseChain

Every block hides value. We ferret it out.

BlockFerret builds PulseChain blocks the honest way. It digs out the value hidden in each one (arbitrage, protocol spreads, rewarded upkeep) and pays the validator 60% of it, on top of the full block reward. It never front-runs, never sandwiches, and never changes the outcome of a user's transaction.

Put BlockFerret to work Read the Ferret Code
BlockFerret, a ferret in a hard hat, work vest and tool belt, holding a glowing green block

Live numbers

What BlockFerret added in the last 48 hours

Every figure comes from blocks BlockFerret actually delivered through the Vouch relay, using each block's own accounting: the reward the validator would have earned from a vanilla block of the same public transactions, and the MEV BlockFerret added on top.

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MEV added — PLS
Vanilla reward — PLS
Vanilla reward — PLS
Typical block —

Figures from block #—, a typical BlockFerret block.

Blocks delivered

—

through the Vouch relay

Blocks with MEV

—

— of them carried added value

Extra paid to validators

— PLS

above the vanilla rewards

MEV added per block

— PLS

on average, above the vanilla reward

Validator reward per block

Hourly averages over the last 48 hours, in PLS. Hours in UTC.

  • Vanilla reward
  • MEV added

Loading live stats…No data available

How we measure

Vanilla reward: for every slot, BlockFerret first builds the ordinary block a validator would get from the public mempool. Its priority fees are the vanilla reward.

MEV added: the validator's 60% of the net MEV in the delivered block, after execution gas, the payout transfer, and any reimbursed fees.

Typical block (the headline): half of BlockFerret's blocks raised the validator's reward by more than this, and half by less. The equation above uses one such block's own numbers.

MEV added per block: all the MEV paid to validators in the window, divided by the number of blocks BlockFerret delivered.

You can check every block BlockFerret delivered in the relay's public data API.

How it works

From mempool to your fee recipient in one slot

  1. Sniff

    BlockFerret watches PulseChain's public mempool: the same transactions every builder sees. No private orderflow, no side deals.

  2. Dig

    For each upcoming block it digs for value: price gaps between exchanges, imbalances left by large trades, protocol spreads and rewarded upkeep.

  3. Inspect

    Every candidate block gets a full safety inspection: it's executed exactly before it's offered. If any user's transaction would turn out differently, the opportunity is dropped.

  4. Deliver

    The block is bid through the Vouch relay. If it wins, the validator receives the full vanilla reward plus 60% of the MEV, paid inside the same block.

What it digs for

Value that's already in the block

BlockFerret doesn't make money by getting in anyone's way. It digs out value that is already there (price gaps, spreads and protocol rewards) and shares most of it with the validator.

Cross-DEX arbitrage

When a token trades at different prices on different PulseChain exchanges, BlockFerret closes the gap, pulling prices back in line for everyone.

Backruns

Large swaps move prices. BlockFerret rebalances them in the same block, strictly after the user's trade has executed at the price they signed for.

Protocol spreads

Some protocols let anyone mint at a fixed rate. When the market pays more, BlockFerret mints and sells in one step, turning the spread into block value.

Protocol upkeep

Many protocols reward anyone who performs routine maintenance: keeper triggers, liquidations of under-collateralized positions, redemptions. BlockFerret watches for them and steps in when they pay.

Strategies run through dedicated executor contracts and are re-proven against every block. We don't publish the blueprints.

Ethics

The Ferret Code

Six rules, enforced in code by the builder's policy engine. A block must pass all six before it leaves the workshop.

  1. Backrun only

    BlockFerret acts only after a user's transaction, never in front of it. No front-running. No sandwiches. Ever.

  2. Users are untouched

    Every user transaction in a BlockFerret block executes exactly as it would have without us: the same success, logs, gas and output. If that can't be proven, the block carries no MEV.

  3. Validators first

    The validator is always paid at least the full vanilla reward for the slot. Any fee displaced to make room is reimbursed before MEV is shared.

  4. A fixed, fair split

    Net MEV is split 60% to the validator and 40% to BlockFerret. The split is compiled into the builder and cannot change from block to block.

  5. Fail closed

    If anything is uncertain, whether a simulation, a price or a receipt, BlockFerret falls back to an ordinary block. Guesswork never reaches the relay.

  6. Every block on the record

    Each block carries a proof of its strategy and accounting, and every candidate is written to a hash-chained audit log tied to the policy that approved it.

BlockFerret will

  • Close price gaps between PulseChain exchanges
  • Rebalance prices after trades, in the same block
  • Capture protocol mint-and-sell spreads
  • Perform rewarded, permissionless protocol upkeep
  • Compete with other bots' arbitrage, never with users. When it outbids a bot, the validator is reimbursed the fee that bot would have paid

BlockFerret will never

  • Front-run a transaction
  • Sandwich a trade
  • Change the outcome of any user's transaction
  • Censor anyone for who they are: not by address, not by app, not by token
  • Trade on private orderflow; it uses the public mempool only
  • Reorganize or rewrite past blocks

For validators

Put BlockFerret to work for your validator

BlockFerret delivers its blocks through the Vouch relay. Run Vouch's PulseChain build of mev-boost next to your beacon node and your validator receives BlockFerret's bids, alongside every other builder on the relay, whenever it proposes.

Vouch relay URL for mev-boost

https://0xa6b974cbc17ce9c37b5f9796e167455d22882f2ca662c19379b0b9c476b1fbe745c19006444b653f9fb8409ffda9a450@boost-relay.vouch.run

  1. Run Vouch's mev-boost sidecar

    Stock mev-boost releases don't work on PulseChain, so use Vouch's build (the pulse branch). The Docker setup comes with the Vouch relay already configured and listens on port 18550.

    # Docker quickstart
mkdir -p mev-boost && cd mev-boost && \
curl -fsSLO https://raw.githubusercontent.com/Vouchrun/mev-boost/pulse/ops/docker-compose.yml && \
curl -fsSLO https://raw.githubusercontent.com/Vouchrun/mev-boost/pulse/ops/mev-boost-config.example.yaml && \
docker compose up -d

  2. Point your clients at mev-boost

    # beacon node
--http-mev-relay=http://127.0.0.1:18550

# validator client
--enable-builder
--suggested-gas-limit=45000000
--suggested-fee-recipient=0xYourFeeRecipient

    Set the gas limit. Both PulseChain clients default to 30M gas while the network runs at about 45M, so without the flag every mev-boost block leaves about a third of its space unused. Start the sidecar first, then restart the beacon node and the validator client, ideally when no proposal is due.

  3. Propose as usual

    Your validator registers its fee recipient with the relay. When it proposes, the relay offers the best bid, and BlockFerret's payment arrives at your fee recipient in the block itself. If the relay is ever unavailable, your client falls back to a local block. You can't end up worse off.

    The setup guide shows how to confirm your registration and your first delivered block. The Docker setup skips bids under 2,000 PLS; those slots are built locally.

mev-boost for PulseChain Vouch's sidecar and setup guide Vouch relay Live relay stats and delivered blocks Every BlockFerret block The relay's public delivery record Vouch vouch.run

FAQ

Questions validators ask

Does BlockFerret cost my validator anything?

No. The validator is always paid at least the vanilla reward for the slot. BlockFerret's 40% comes only from the MEV it adds on top, never from your ordinary fees.

How is the increase calculated?

For every block BlockFerret delivered in the last 48 hours we compare what the validator was paid with the vanilla reward: what an ordinary block of the same public transactions would have paid. The headline is the typical block: half of BlockFerret's blocks raised the validator's reward by more than that, and half by less. Blocks without MEV are included.

What happens when another builder wins my slot?

Nothing changes for you. The relay simply gives you the highest bid. BlockFerret only earns when its block is the one you sign.

Can BlockFerret hurt the users in my block?

No, by construction. Rules I and II of the Ferret Code are checked by exact execution before every bid. If any user transaction would land differently, the MEV is dropped and an ordinary block is offered instead.

Do I need to change my fee recipient or keys?

No. You keep your own fee recipient and keys. BlockFerret pays you with a transfer inside the block it built, and the relay verifies the bid before it ever reaches you.

Which mev-boost do I need?

Vouch's PulseChain build: the pulse branch of Vouchrun/mev-boost, also published as the Docker image ghcr.io/vouchrun/mev-boost:pulse. Stock flashbots releases don't support PulseChain. Its setup guide covers Docker, the client flags (including the 45M gas limit) and how to check that everything is working.

Who runs the relay?

The relay is operated by Vouch. It's a standard mev-boost relay that any PulseChain validator can connect to, and its public page shows live stats and every delivered block.

Ready to put a ferret on the job?

Run Vouch's mev-boost with the Vouch relay and BlockFerret starts bidding for your blocks.

Put BlockFerret to work