flashbot

What Is Flashbots?

Flashbots is a suite of research and infrastructure projects focused on Ethereum, specifically addressing the value and risks associated with transaction ordering. It provides tools for protecting and optimizing transactions. The main goal is to make user transactions more predictable while allowing validators to capture order-related rewards in a compliant manner.

On-chain, transactions are broadcast and sequenced before inclusion in a block. Some actors profit from manipulating this sequence, a phenomenon known as Maximal Extractable Value (MEV). Flashbots shifts transactions from public exposure to a controlled environment using private relays, and leverages transaction bundling and auction mechanisms to enhance transparency and reduce negative impacts.

Why Is Flashbots Relevant to MEV?

MEV refers to the additional value that can be extracted by changing the order or selection of transactions in a block. When transactions are publicly broadcast, their details are exposed, making them vulnerable to frontrunning and sandwich attacks.

Think of the public mempool as a notice board in an open marketplace: when large swaps are spotted early, attackers can insert their own transactions before and after the user's swap, artificially pushing prices up and then back down. The user ends up transacting at a worse price. Flashbots seeks to turn this hidden value into a transparent, researchable, and governable process, mitigating the harm to regular users.

How Does Flashbots Work?

Flashbots’ core concept is to route transactions through private relays where professional “builders” aggregate them into candidate blocks. These candidates are then auctioned off to validators, reducing public exposure and distributing ordering profits via explicit channels.

The main participants are:

• Users or developers submit transactions through protected channels instead of broadcasting to the public mempool.
• “Searchers” identify opportunities and bundle related transactions.
• “Builders” assemble these bundles into optimal candidate blocks.
• Private “relays” securely deliver candidate blocks to validators for proposal.

For example, consider swapping tokens on Uniswap: if submitted via the public mempool, the transaction could be sandwiched, impacting the execution price. Submitting via the Flashbots protected channel conceals transaction details until they’re included in a bundle, which is then processed by builders and finally validators, significantly reducing sandwich attack risk.

How Does Flashbots Operate After The Merge with MEV-Boost?

After Ethereum transitioned from Proof of Work to Proof of Stake, block proposals are made by validators. Flashbots’ MEV-Boost allows validators to select the most profitable candidate blocks from multiple builders before proposing a block.

MEV-Boost acts as a secure "block auction" interface: builders submit candidate blocks with attached bids, relays transmit them, and validators quickly select and sign off on the highest bid. This Proposer-Builder Separation (PBS) model decentralizes control over ordering, enables specialization and transparency in MEV extraction, and preserves user protection mechanisms.

What Are The Benefits of Flashbots? What Do Users and Developers Gain?

For users, Flashbots reduces sandwich attacks and frontrunning, making large transactions more stable and closer to expected prices. For developers, it provides research data, private submission endpoints, and bundling interfaces to design more attack-resistant applications.

Protected channels are crucial in decentralized trading and environments with high-frequency liquidation bots. For batch operations, auctions, or airdrop claims—where transaction order is critical—bundling and private relays help reduce the risk of adversarial reordering.

How To Use FlashbotsProtect?

FlashbotsProtect enables users to send transactions through protected relays. Commonly, this involves configuring a wallet with a dedicated RPC endpoint or activating protection options within an application.

Step 1: Add the Protect RPC endpoint to your wallet (one that supports custom RPCs), ensuring it points to Ethereum mainnet.

Step 2: When sending a transaction, select the Protect connection so your transaction bypasses the public mempool.

Step 3: Check transaction simulations or set minimum acceptable price ranges to avoid losses from excessive slippage.

Step 4: Submit the transaction and wait for confirmation. The protected channel forwards your transaction to builders and validators, typically bypassing sandwich attacks and frontrunning.

How Is Flashbots Different From Public Mempool Transactions on Public Blockchains?

Transactions in public mempools are visible to everyone—like being displayed on a giant screen—making them susceptible to frontrunning. Flashbots’ protected channel acts like a sealed envelope: only authorized parties can access and process these transactions.

Key differences include:

• Visibility: Public broadcasts are easily monitored; protected submissions reduce exposure.
• Ordering Opportunities: Sandwich attacks are more prevalent in open environments; protected channels shift opportunities to controlled bundling and bidding.
• Cost Experience: Protected channels usually result in execution closer to expected prices but require careful slippage and fee settings.

What Are The Risks And Limitations Of Flashbots?

Protection isn’t absolute. Relays and builders form part of the core infrastructure, introducing centralization risks and trade-offs related to compliance strategies. Some relays might reject certain transactions due to regulatory or technical policies, causing delays or failures.

Additionally, during periods of network congestion, protected channels may be less competitive than public paths. Users should remain aware of slippage risks, gas fee limits, and smart contract vulnerabilities. Ultimate asset safety depends on private key management and contract audits—protection does not guarantee absolute security.

How To Use Flashbots With Gate?

After withdrawing assets from Ethereum on Gate, you can enable FlashbotsProtect RPC when using a self-custody wallet for Uniswap or other DeFi activities. This reduces the risk of sandwich attacks.

For example, when planning a large token swap: switch your wallet connection to Protect, set appropriate slippage and gas parameters, send the transaction, and wait for confirmation. For batch claims or participating in auctions—operations highly sensitive to order—it’s also advisable to use protected submission channels.

What Is The Future Outlook For Flashbots?

Over the past two years, MEV research and infrastructure have steadily evolved. Validators increasingly collaborate with professional builders and relays. Looking ahead, more applications are expected to integrate protection options for users at the interface level, while PBS mechanisms may become standardized at the protocol level.

Overall, Flashbots is transforming "invisible ordering games" into transparent, researchable processes. As tools and standards mature, user experience and ecosystem transparency should continue to improve—but balancing protection with openness will require ongoing collaboration between community members and protocol developers.

FAQ

Will Using Flashbots Make Me A Target For Hackers? Is My Crypto Safe?

Flashbots Protect hides your transaction contents for privacy so hackers cannot see your orders in advance. However, it only safeguards transaction privacy—not your wallet itself. You are still responsible for secure key management and guarding against phishing threats. Using hardware wallets is recommended for an extra layer of protection.

As A Regular Trader, Will I Save Money Using Flashbots?

For typical users, the primary benefit of Flashbots is avoiding frontrunning (sandwich attacks) and slippage losses—it does not necessarily save on gas fees directly. If you frequently trade large amounts in DeFi, Flashbots Protect can shield you from MEV bots, which may result in significant savings. For small trades, the difference may be less noticeable; assess your usage pattern before deciding.

Which Blockchains Does Flashbots Support? Is It Only Ethereum?

Flashbots currently operates mainly within the Ethereum ecosystem; its core products are optimized for Ethereum mainnet. As scaling solutions like Arbitrum and Optimism grow, Flashbots is exploring cross-chain support. Other blockchains have their own MEV mitigation tools but Flashbots’ infrastructure is primarily Ethereum-focused for now.

What Happens If I Trade Directly On Gate Without Using Flashbots? What’s The Difference?

Even when trading on exchanges like Gate, your orders settle on-chain and may still face MEV risks—arbitrage bots could insert orders around yours for profit. Using Flashbots Protect conceals your trades from public view, preventing sandwich attacks. While regular users may not feel this acutely, large or frequent traders can significantly reduce hidden costs with Flashbots.

Does Flashbots Make Money? What Is Its Business Model?

Flashbots is currently a non-profit research organization supported mainly by the Ethereum Foundation and community contributors. Services like Flashbots Protect are free; its influence comes from academic research and open-source contributions. In the long term, sustainable business models may emerge—but for now, its focus remains on advancing MEV mitigation technology and securing the Ethereum ecosystem.