Skip to main content

Quick Start

This quickstart guide contains all the information necessary to get up and running as a searcher on Flashbots. If you have any questions, do not hesitate to ask in the '#🐣 newcomers' or '#🤖 searchers' discord channels, or in the Searcher Self-Support Forum.

See you on-chain! ⚡🤖

Bundle Relay URLS​

NetworkURL
Mainnethttps://relay.flashbots.net
Goerlihttps://relay-goerli.flashbots.net
Sepoliahttps://relay-sepolia.flashbots.net

Who should use Flashbots Auction?​

  1. Ethereum bot operators (we call them "searchers") looking for fast, and risk free access to blockspace (for example, arbitrage and liquidation bots)
  2. Ethereum users looking for frontrunning protection on their transactions (for example, Uniswap traders)
  3. Ethereum Dapps with advanced use cases like account abstraction or gasless transactions

How does Flashbots work for searchers?​

Flashbots connects searchers to validators (previously "miners") while allowing them to avoid the public tx pool. Searchers with transactions they would like to send first craft what we call "bundles" and send these to a block builder such as Flashbots. The builder simulates the bundles to ensure there are no reverts, and then builds a full block with the available bundles and transactions. Via mev-boost and the network of relays and builders, these blocks are received by validators while maintaining pre-trade privacy.

Getting onboarded to Flashbots is easy for searchers; you simply need to update how you send transactions.

How to send your first Flashbots bundle​

To access the Flashbots network you will need three things:

  1. A private key that Flashbots can use to identify you
  2. A way to interact with the Flashbots network
    • Alchemy offers an easy way to send single transactions to Flashbots.
  3. A "bundle" for your transactions

Let's begin with the private key Flashbots uses for identity. When you send bundles to Flashbots you will sign them with a private key so that we can establish identity for searchers and establish reputation for them over time. This private key does not store funds and is not the primary private key you use for executing transactions. Again, it is only used for identity, and it can be any private key.

Second, you'll need a way to interact with Flashbots. The Flashbots builder receives bundles at relay.flashbots.net, and we have specific RPC endpoints you'll need to use to send us transactions. We've integrated with a few popular developer tools like Ethers.js or web3.py to make interacting with Flashbots as easy as possible. Here are a few examples of how to set up a Flashbots provider:

const ethers = require("ethers.js");
const {
  FlashbotsBundleProvider,
} = require("@flashbots/ethers-provider-bundle");
const provider = new ethers.providers.JsonRpcProvider({
  url: ETHEREUM_RPC_URL,
});
// Standard json rpc provider directly from ethers.js. For example you can use Infura, Alchemy, or your own node.

const authSigner = new ethers.Wallet(
  "0x0000000000000000000000000000000000000000000000000000000000000000"
);
// `authSigner` is an Ethereum private key that does NOT store funds and is NOT your bot's primary key.
// This is an identifying key for signing payloads to establish reputation and whitelisting

const flashbotsProvider = await FlashbotsBundleProvider.create(
  provider,
  authSigner
);
// Flashbots provider requires passing in a standard provider and an auth signer

Now that we have a private key to identify ourselves with and a Flashbots provider we can create and send a bundle. Here's an example in node.js

const ethers = require("ethers.js");
const {
  FlashbotsBundleProvider,
} = require("@flashbots/ethers-provider-bundle");
const provider = new ethers.providers.JsonRpcProvider({
  url: ETHEREUM_RPC_URL,
});

const authSigner = new ethers.Wallet(
  "0x2000000000000000000000000000000000000000000000000000000000000000"
);
const flashbotsProvider = await FlashbotsBundleProvider.create(
  provider,
  authSigner
);

const signedBundle = await flashbotsProvider.signBundle([
  {
    signer: SOME_SIGNER_TO_SEND_FROM,
    transaction: SOME_TRANSACTION_TO_SEND,
  },
]);

const bundleReceipt = await flashbotsProvider.sendRawBundle(
  signedBundle,
  TARGET_BLOCK_NUMBER
);

That's it!

Next steps​

Congrats! You should now have everything you need to start sending transactions to the Flashbots network.