bloXroute lets you Rent A MEV Searcher

bloXroute Team
4 min readOct 14, 2021


By: Eyal Markovich, Co-Founder & COO

Several months ago, we introduced the BackRunMe service to the Ethereum ecosystem. The idea of coupling front-running protection with additional payback to users has garnered us great feedback from the community.

BackRunMe is a novel service that allows users to dodge front-running and sandwich attacks by safely submitting private transactions while authorizing searchers to extract positive MEV (Miner Extractable Value) from their transactions if their transaction creates an arbitrage opportunity. The most important part of BackRunMe is that a large portion of this additional profit captured by the searchers will be rewarded to the users.

Over the last year, frontrunning protection has received more attention and more players have joined the race. In order to benefit more users, we’re excited to announce a new service that will enable other DeFi protocols and projects to provide a BackRunMe-like service to increase their users’ trading profits.

Theoretically, every project with access to private transactions can run an arbitrage bot to capture the arbitrage opportunity by themselves. However, building and running such bots is a full-time job and also faces a lot of risks. Since it’s the same work that our traders (searchers) are already doing for their business, why not let other projects save time and effort by granting them access to our BackRunMe searchers? So we call this new service “Rent-A- Searcher” — granting projects access to our searchers so that their users can not only avoid frontrunning attacks but also have a chance to earn additional MEV profit. More importantly, it will help create a better offering. So why miss out on free profit for your users?

How does Rent-A-Searcher work?

If you’re a private transaction and MEV service provider, there are two ways for you to leverage our searcher capacity and there’s a slight difference between them.

  • Integrate with BackRunMe. The private transaction and MEV bundles will be submitted to the mining pools directly by bloXroute.
  • Integrate with Rent-A-Searcher. bloXroute will send the arbitrage transactions back to the service provider who will be responsible for creating and submitting the bundles to the mining pools.

mistX is a great example of how Rent-A-Searcher works in real life. They have recently announced the integration with the Rent-A-Searcher service that has generated outstanding cashback rewards to their users.

(Source: Award leaderboard from the Medium post Did somebody say rewards? mistX rolls out an exciting new feature)

Let’s take a close look at this specific example:

This user used the mistX router to swap NFD and DOG tokens with ETH, and paid a total fee of 0.03 ETH. Below is what happened behind the scene.

  1. In this case, the user’s main goal was to protect their transaction against sandwich attacks so that they submitted a private transaction to mistX protection (the user could also use bloXroute Frontrunning Protection or other private transactions services).
  2. mistX forwarded the transaction to bloXroute who then sent this transaction’s metadata to a few searchers who would check if there’s a potential opportunity for arbitrage. In this case, there was an opportunity and a transaction to capture it was submitted to mistX (0xde4f243c196afb19aa55fffab86e62e24efd7679b497e9cfe2797fcf9ba26b43).
  3. mistX added the arbitrage transaction after the private one and sent both of them to the Flashbots relay in the same MEV bundle. They were eventually mined in block 13152727.
  4. To the user’s surprise, a reward of 1.04ETH was sent to their wallet instantly after the success of their transaction. As a result, this user not only avoided frontrunning attacks, but also earned almost 10 times of the transaction fee they paid, for FREE!

Who should use the “Rent-A-Searcher ” service?

Any organization or individual currently using private transactions (e.g. Flashbots, Eden, bloXroute) and lacks the know-how of arbitrage searching should take advantage of “Rent-A-Searcher”. The integration process is very simple and can be completed fairly quickly.



bloXroute Team

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