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Getting Started

To start searching on MEV-Share, you will first need to connect to a MEV-Share Node. As a reminder, the MEV-Share Node is responsible for receiving transactions and bundles from users, and selectively sharing information ("hints") about them with searchers. When a searcher wants to include a transaction in their bundle, they use that transaction's hash. The MEV-Share Node replaces it with the original transaction before sending the bundle to a block builder.

Connect to MEV-Share Node​

Flashbots operates an MEV-Share Node on the Ethereum mainnet. This Node provides endpoints for user transactions and searcher bundles. Additionally, it offers an SSE event stream endpoint, broadcasting pending events/transactions to searchers.

The simplest way to connect to the Flashbots MEV-Share Node is to use a client library. For this guide, we'll refer to mev-share-client-ts.

Add library to your project:

yarn add @flashbots/mev-share-client

Use the following code to import the library (Replace ALL_CAPS placeholders with your data):

import { Wallet, JsonRpcProvider } from "ethers"
import MevShareClient, {
    BundleParams,
    HintPreferences,
    IPendingBundle,
    IPendingTransaction,
    TransactionOptions
} from "@flashbots/mev-share-client"

const provider = new JsonRpcProvider(RPC_URL)
const authSigner = new Wallet(FB_REPUTATION_PRIVATE_KEY, provider)
const mevShareClient = MevShareClient.useEthereumMainnet(authSigner)

Connecting to Goerli:

const mevShareClient = MevShareClient.useEthereumGoerli(authSigner)

Advanced setup (for developers):

// connect to MEV-Share on mainnet
const mevShareClient = new MevShareClient(authSigner, {
    name: "mainnet",
    chainId: 1,
    streamUrl: "https://mev-share.flashbots.net",
    apiUrl: "https://relay.flashbots.net",
})

Further documentation on the client library can be found in the mev-share-client-ts.

A note on other languages​

If you're coding in a language that doesn't yet have a MEV-Share Node client library, you can send transactions and bundles directly with the JSON-RPC endpoint. To listen for transactions, all you need is an HTTP client. More details on that in the Event Stream page.

Now you should be connected to the Flashbots MEV-Share Node. Continue reading on the next page to learn how to listen for hints about pending transactions shared by the MEV-Share Node.

A note for experienced searchers getting acquainted with MEV-Share

Searching on MEV-Share is different from searching on the mempool in that only certain parts of a transaction are shared with searchers. In the mempool, we can see all parts of a transaction, such as its calldata or who the transaction is from. But on MEV-Share, a transaction might only reveal its function selector, making a traditional arbitrage calculation infeasible.

There are three primary strategies for searching on MEV-Share:

  • Probabilistically: send many bundles that probabilistically backrun MEV-Share orderflow.
  • On-chain: perform more of your searching on-chain instead of off-chain.
  • Existing: only search on transactions which share all the information you need.

To maximally leverage MEV-Share searchers will need to employ new strategies.