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Testnets

Flashbots operates on Goerli and Sepolia, so that searchers can test Flashbots without risking real funds.

Bundle Relay URLS

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

Examples

Here's how to setup the Flashbots Bundle Provider in Ethers to use Goerli or Sepolia:

const provider = new ethers.getDefaultProvider("goerli");
// uncomment the line below to use Sepolia
// const provider = new ethers.getDefaultProvider("sepolia");

const authSigner = new ethers.Wallet(
'0x2000000000000000000000000000000000000000000000000000000000000000',
provider
);

const flashbotsProvider = await flashbots.FlashbotsBundleProvider.create(
provider,
authSigner,
// use "https://relay-sepolia.flashbots.net" for Sepolia
"https://relay-goerli.flashbots.net",
"goerli"
);

Sending bundles works the same as sending bundles on the mainnet. For example this will simulate a bundle and if it is successful then send a batch of 10:

const wallet = new ethers.Wallet(SOME_PRIVATE_KEY);
const signedTransactions = await flashbotsProvider.signBundle([
{
signer: wallet,
transaction: {
to: "0xf1a54b075fb71768ac31b33fd7c61ad8f9f7dd18",
gasPrice: 10,
gasLimit: 21000,
chainId: 5,
value: 0,
},
},
{
signer: wallet,
transaction: {
to: "0xf1a54b075fb71768ac31b33fd7c61ad8f9f7dd18",
gasPrice: 10,
gasLimit: 21000,
chainId: 5,
value: 0,
},
},
]);

const blockNumber = await provider.getBlockNumber();

console.log(new Date());
const simulation = await flashbotsProvider.simulate(
signedTransactions,
blockNumber + 1
);
console.log(new Date());

// Using TypeScript discrimination
if ("error" in simulation) {
console.log(`Simulation Error: ${simulation.error.message}`);
} else {
console.log(
`Simulation Success: ${blockNumber} ${JSON.stringify(
simulation,
null,
2
)}`
);
}
console.log(signedTransactions);

for (var i = 1; i <= 10; i++) {
const bundleSubmission = flashbotsProvider.sendRawBundle(
signedTransactions,
blockNumber + i
);
console.log("submitted for block # ", blockNumber + i);
}
console.log("bundles submitted");

The reason why we submit bundles for the next 10 blocks is because Flashbots only runs a small portion of the validators on Goerli. We are more likely to have a bundle included if we submit bundles for several blocks into the future.