Can builders unbundle and include extra transactions in searcher's bundle?

Block Builders
1

Suppose I am a searcher who sends a bundle to a builder for arbitrage that requires sequential execution. Can the builder insert additional transactions in my bundle to attack me? How is the searcher protected in this scenario?

1 Like
2

Block builders today have full control of the content in their blocks and have the ability to remove and/or insert transactions at any position. You can find some more details on how searchers and builders interact, and a some criteria to look for in a block builder, in our Documentation and in Searching Post-Merge.

We are working on reducing these trust assumptions, since March we’ve been running a block builder inside an SGX enclave, bringing us one step closer toward transaction confidentiality and decentralization of the block-building role.

Moving forward, with SUAVE, we seek to substitute these trust guarantees further with robust cryptographic and cryptoeconomic assurances for comprehensive programmable privacy.

1 Like
3

How to send bundles to a block builder? I am running falshbots block builder and need to send bundles to block builder. I used the following code, used BUILDER_URL, does not work.

const flashbotsProvider = await FlashbotsBundleProvider.create(
RPC_PROVIDER, // ethers.js provider, to perform gas estimiations and nonce lookups
wallet, // ethers.js signer wallet
BUILDER_URL,
BLOCKCHAIN_NAME
);

for (var i = 1; i <= 10; i++) {

    //bundle submission
    const bundleSubmission = await flashbotsProvider.sendRawBundle(
        signedTransactions,
        blockNumber + i
    )
    const waitResponse = await bundleSubmission.wait()


    //check bundle inclusion
    if (
        waitResponse === FlashbotsBundleResolution.BundleIncluded ||
        waitResponse === FlashbotsBundleResolution.AccountNonceTooHigh
    ) {
        console.log('Bundle included !!!')
        process.exit(0)
    } else {
        console.log("bundle not included !!!" + i)
        console.log({
			bundleStats: await flashbotsProvider.getBundleStats(
				simulation.bundleHash,
				blockNumber + 1,
			),
			userStats: await flashbotsProvider.getUserStats(),
		})
    }
}