Building Ethereum's Searcher Bots: A Guide to Maximal Extractable Value Extraction

In 2026, Ethereum's maximal extractable value (MEV) capture stands at around $24 million per month, which annualizes to over a quarter billion dollars. This activity is not just about profit; it also provides an opportunity for developers and builders to understand how the MEV extraction process works.

A 'searcher bot' plays a crucial role in this process by identifying profitable trades and packaging them into Flashbots bundles, which are then submitted to relays. These bots use various strategies such as arbitrage, triangular arbitrage, sandwich attacks, and liquidation bounties to capture MEV.

To build a searcher bot from scratch, one must first set up a project and install dependencies like Node.js, ethers.js, Foundry, and Flashbots' ethers-provider-bundle. Then, obtain an RPC endpoint and a burner wallet for signing bundles without touching the mainnet.

Throughout this process, it is essential to understand the mechanics of MEV extraction, including bundle construction, simulation, relay submission, and gas accounting. This knowledge can help developers create MEV-resistant applications and better comprehend the inner workings of Ethereum's infrastructure.