Constitutional AIP: Proposal to adopt Timeboost, a new transaction ordering policy

Submitted by: The Arbitrum Foundation
Category: Constitutional, Software Upgrade


This AIP proposes the adoption of Timeboost, a new transaction ordering policy for Arbitrum One and Nova. Timeboost enables auctions for the rights to an express lane, giving the winner an advantage for transaction inclusion and allowing them to potentially capture arbitrage and backrunning opportunities. Proceeds from the auction are at the discretion of the Arbitrum DAO, with two main options outlined in this proposal: collecting bids in ETH or collecting bids in ARB.


Arbitrum Chains currently order transactions on a First-Come First-Served basis (FCFS). The motivation to implement FCFS was twofold:

  1. Easy to understand and implement,
  2. Replicate Web2 user experience for instant transaction confirmation,

Unfortunately, relying solely on first-come first-served transaction ordering is not an ideal long-term solution.

When opportunities to profitably arbitrage across exchanges arise on Arbitrum, “MEV Searchers” race to get their transaction included before anyone else so that they can capture this profit. This latency race involves a lot of spam, placing stress on chain infrastructure and causing searchers to wastefully invest in faster hardware. Furthermore, none of the MEV generated is captured by the chain and instead all profits are collected by searchers.

Timeboost is a new transaction ordering policy that retains many of the great benefits currently in place for Arbitrum chains, including frontrunning protection and fast block times, while allowing the chain to reduce negative externalities from the racing behavior induced by MEV searchers. Additionally, it can socialize the benefits of the transaction sequencing market back to the ArbitrumDAO.


Sustainable: Timeboost offers the ArbitrumDAO an opportunity to capture additional revenue that does not come at the expense of users, since the value being captured already exists.

Technically-Inclusive: Rather than capturing arbitrage opportunities by having the fastest hardware, participants can win these opportunities by bidding in an auction.

Neutral and Open: The auction for the express lane is permissionless and participation is open to everyone, where the highest bid wins.

Empowerment: The Arbitrum DAO can configure all aspects of Timeboost, including enabling or disabling it, the auction’s design, and how to handle proceeds.

Key Terms

Express Lane: A separate path for submitting transactions to the sequencer that has priority access compared to normally submitted transactions.

MEV: Maximal extractible value. In the context of Timeboost, MEV refers to the maximum amount of profit someone could make by including their transactions slightly faster than anyone else.


The full specification for the Timeboost auction can be found here: GitHub - OffchainLabs/timeboost-design

Arbitrum chains that adopt Timeboost will have two paths for transaction submission:

  • Normal path: Transactions in the normal path will experience a short delay (defaulted to 200ms) but will otherwise remain unchanged.
  • Express lane: Transactions in the express lane do not experience any delay.

Access to the express lane would be auctioned off in one-minute rounds, with the auction happening 15 seconds before the round begins. Bids are kept private until after the bid submission deadline, and the auction winner will pay the same price as the second-highest bid of that round. There are two reserve prices, which determine the minimum bid one can place, that are configurable by the DAO. The first is a “minimum reserve price,” which is set by governance. The second is a “current reserve price.” An address designated by governance can call the auction contract to change the current reserve price to any value greater than or equal to the minimum reserve price. To start, the proposed minimum reserve price is 0.001 ETH or 3 ARB per round (depending on what currency the DAO votes to collect bids in), and there is no address designated to change the current reserve price. The reserve prices are only meant for establishing a minimum bid, and does not represent what the expected value of the express lane will be. There are two main components that facilitate the express lane auction:

  • Auction contract: Prospective bidders must deposit funds into the auction contract before bidding in the auction. The contract is also responsible for verifying bidders’ signatures, checking auction contract account balances, deducting the second-highest bid amount from the account of the highest bidder, and handling the proceeds.
  • Autonomous auctioneer: An offchain program that captures bids from participants and reports the top two bids to the auction contract. This AIP proposes that the sequencer act as the autonomous auctioneer if Timeboost is adopted.

The proposed version of Timeboost is compatible with a centralized sequencer, however, the Timeboost policy will be compatible with proposals for a decentralized sequencer. 3% of auction proceeds would be left aside for the Arbitrum Developer Guild, which helps fund core Arbitrum development.

The ArbitrumDAO can configure the currency in which bids are collected and how the auction proceeds are handled. This AIP proposes two main options that the community can vote on if it decides to adopt Timeboost. Governance can change these options at any time.

  • Collect ETH: Collect bids in ETH and send the proceeds to the DAO treasury.
  • Burn ARB: Collect bids in ARB and burn the proceeds.

Depending on which option the Arbitrum DAO chooses, the auction contract can either transfer the proceeds to a designated account or burn them.

Steps to Implement

If the Arbitrum DAO approves the AIP, the path would consist of:

  1. Discussion of the proposal on the forum and governance call(s)
  2. A vote on Snapshot to decide between Option 1 (collect ETH), Option 2 (burn ARB), or Option 3 (don’t adopt Timeboost)
  3. Sufficient time for testing on a public testnet
  4. An onchain vote to deploy the upgrade on Arbitrum One and Arbitrum Nova


  1. What’s an ELI5 on Timeboost?

Timeboost is a new transaction ordering policy for Arbitrum chains where participants can bid for the right to get their transactions included slightly faster than anyone else. Importantly, user transactions will still remain private until after they are executed, meaning that no one can frontrun or sandwich users. Timeboost bids are collected by the Arbitrum DAO in either ETH or ARB, depending on DAO approval.

  1. As a typical user, will I notice any difference in my experience?

The only difference users should experience is a small delay when submitting their transactions. The default configuration for this delay is 200ms and can be changed by the Arbitrum DAO. This delay is to give the express lane controller an advantage so they are able to include transactions slightly quicker than others. Importantly, user transactions will still remain private until after they are executed, meaning that the express lane controller cannot frontrun or sandwich users.

  1. Where does the Timeboost income stream come from?

Timeboost auctions the rights to an express lane, giving the winner an advantage for transaction inclusion and allowing them to capture arbitrage and backrunning opportunities. Proceeds from the auction are at the discretion of the Arbitrum DAO, with two main options outlined in this proposal: collecting bids in ETH or collecting bids in ARB.

  1. What is the difference between the two options?

This AIP proposes two main options that the community can vote on if it decides to adopt Timeboost. Governance can change these options at any time.

  • Option 1: Collect bids in ETH and send the proceeds to the DAO treasury.
  • Option 2: Collect bids in ARB and burn the proceeds.

Depending on which option the Arbitrum DAO chooses, the auction contract can either transfer the proceeds to a designated account or burn them.

  1. How can I participate in Timeboost directly?

Interested parties can participate in the Timeboost auctions by depositing funds in the auction contract and sending bids to the autonomous auctioneer. We will have docs with more information.

The Timeboost auction is open to everyone; however, only parties interested in capturing arbitrage or backrunning opportunities will benefit from winning it. Timeboost works behind the scenes with minimal impact on normal users, generating revenue for the Arbitrum DAO.

  1. How much estimated revenue will this drive to the DAO?

Estimating how much revenue Timeboost will generate is difficult and based on many factors. There are no ways to confidently estimate the amount of arbitrage or backrunning opportunities that will exist on Arbitrum chains in the future. The expectation is that the revenue will be significant on Arbitrum One due to the high amount of DeFi activity.

  1. Does it work with Orbit chains?

Timeboost can be adopted by Orbit chains, and they can also choose different tokens from ETH or ARB to be paid in if they wish. For example, a chain could choose to accept its own token for the auction.

  1. Will there be a testnet for Timeboost?

Timeboost will be enabled on internal devnets and Arbitrum Sepolia prior to Arbitrum One and Nova.

  1. What is the timeline for Timeboost?

Timeboost is at the beginning of the governance process and must undergo forum discussion, a Snapshot vote, and an onchain vote before being adopted on mainnet.

  1. Will it work with future decentralized Arbitrum sequencers?

The proposed version of Timeboost is only compatible with a centralized sequencer, however, a future version that works with a decentralized sequencer is under development. This allows us to deliver Timeboost sooner, rather than waiting until the decentralized sequencer is complete.



very interesting proposal and idea behind Timeboost.
Basically its a “sniper tool” for MEV searcher, NFT sniper and every other situation where one needs to be fast.

What is going to happen if, lets says, every user is deciding to use the fast lane. Who will be the winner then?

Also I would tend to Option 2, collect in ARB and burn.
One could say we need more ETH in the treasury, but I do think the main problem is not that we need more ETH, rather the DAO should focus more on spending and budgets.


Very interesting proposal, it’s a great way to increase revenue while not really disrupting the MEV scene on Arbitrum for average users.

As we are moving closer to ARB staking and some kind of revenue distribution, I believe it makes more sense to collect fees in ETH to also keep some consistency with the rest of fees on the network.

Just curious of a few technical aspects of timeboost:

  1. As the express lane auctions happen every minute, in a situation with no usage what would be the minimum auction price be? Would it be the same cost of using the normal path or would the reserve price be set up in a way so that it is always guaranteed to cost more and therefore generate higher fees for Arbitrum?
  2. Does the starting bid depend on previous time slot bid price helping to capitalise more in periods of high activity or it always starts from the same constant reserve price?

Great post! This is @yusufxzy from Delphi Digital. A couple of questions-

  1. Its helpful to have prospective bidders place a deposit in order to bids. I assume this mechanism is in place to avoid spam from searchers. How is this deposit value quantified?

  2. What does block construction look like when the Time Boost is in place? Does the sequencer have to place the express bundles atop other, normal bundles? What if there is a delay in receiving the express bundle? Does it delay the block building process? What are some mechanisms in place to avoid such situations?

  3. What would happen in case the autonomous auctioneer goes offline? Would Arbitrum revert to FCFS as a fall back immediately? What measures do we have to protect against the autonomous auctioneer down-time? Who would manage this auctioneer?


We should start to think about how to drive value back to the Arb token with new initiatives like this. I propose two possible solutions:

  1. Allow users to stake ARB tokens in order to receive a share of the fees generated by the auction
  2. Require users to stake a certain amount of ARB in addition to paying the auction fee to get access to this priority transaction lane - could also allow people to delegate ARB to a specific user in return for a share of the profits from the MEV to reduce the up front capex for smaller players

There is only one option: consume arb
A good ecosystem is a positive cycle. Arbitrum should use arb as the center of the ecosystem to spread outward. The current competitive landscape of L2 is unclear. The functions of each other are not irreplaceable. Doing something well is not about doing it well, but about making it different. I believe this is a good start.


Timeboost is going to take Arbitrum DAO to the next level. Absolutely stoked for this one! I still need to dig into the technicals, but I am obviously supportive of this initiative… as I am sure most community members will be.

In reference to the below:

I believe it is a no brainer to collect the fees in ETH and send the proceeds to the treasury where they can be leveraged to earn additional yield into perpetuity. I understand people want ARB utility ASAP, but I firmly believe that we can build up a treasury worth 10s of billions of dollars of ETH and Stables over time. Once we reach that point, I will be in favor of protocol revenue share with token holders through some type of mechanism.

I believe it is extremely important for the DAO to have a longterm mindset on these types of issues rather than rushing to share profit or burn ARB tokens during our early stage growth phase. Do we really want to be in a situation where we enter a bear market with a treasury w/ 99% of its assets in ARB with no inherent staking yield, and minimal yield opportunities / liquidity when compared to ETH? Or do we want hundreds of millions (and eventually billions) of dollars of ETH and Stables that can earn at minimum the ETH staking yield and US short term treasury yield?

To me, the answer is obvious. I want Arbitrum to be well capitalized over the coming decades, rather than essentially buying our token at a valuation that has a ton of speculative premium priced in and sending it to an EOA that no one controls or benefits from…


I propose a third option for profit distribution.
Distribute 100% of the received ARB to ARB stakers (if such staking is accepted)
In any case, I believe that there is no point in burning ARB: there are many ways to properly distribute profits.


I believe the adoption of Timeboost is a beneficial move for Arbitrum, as it not only addresses MEV-related challenges but also creates a sustainable revenue stream for the DAO. I agree with @cp0x suggestion to distribute ARB proceeds to stakers, which fosters community engagement and aligns incentives without reducing the ARB supply through burning.


Distributing the proceeds to Stakers creates selling pressure. Typically, stakers sell their staking income, such as salary, at the end of the month. However, if there is a constantly burning supply, it activates the holding psychology more and people theoretically hold it as if they were Staking, without receiving Stake income. Burning is more positive for pricing.
I think the staking mechanism should be placed at the center of Bold in the future when price stability is achieved. @cp0x @0xTALVO.ETH_MTY


Overall the idea sounds exciting and I’m aligned with most of the positive arguments highlighted in the convo, but I do have a few reservations:

1. Technical implementation
As @yusufxzy and @0x_ultra highlighted above, having more information about some mechanisms and technical details would be helpful, in particular re the auctioneer management and potential associated risks.

2. Data and projections
Is there any existing data on similar implementations on other chains that we could refer to? If not, do we have any projections or models to rely on? Specifically, data on how this change might impact arbitrage behavior – based on the potential increase of transaction costs and block time. How much those increases could impact the current arbitrage opportunities – which in turn might affect traffic? This is a pretty important consideration imho, and having a past study or projections would help assess the potential impact more clearly.

3. Profits redistribution
The DAO’s recent focus has mostly be on strengthening its treasury and enhancing ARB’s utility, which isn’t a bad thing in itself, but I feel like we’re forgetting there are other options. For instance, could we consider redistributing a portion of the profits (in ARB?) generated to the protocols used by these transactions? This feels like a fair and easy way to incentivize protocols by actually rewarding them for real contributions and activity on the chain.


gm, super interesting proposal - thank you for sharing. Arbitrum developers confirmed to be superstars who always look at new win-win improvements for the ecosystem.

I would like to understand better who would be the target user of this (maybe asking some dumb questions here):

What type of MEV activity exists today on Arbitrum? What do searchers search for?

Similarly, with this type of timeframe, what kind of transactions would go through the fast lane?

On top of the 2 options proposed, I lean towards accumulating ETH in the Treasury, until we agree on the best way to distribute it and/or we have accumulated enough reserves.

In general, I would exclude token burning because it doesn’t inherently increase the fundamental value of the token:


I share most of this but wanna focus on 3.

While i think we should go for eth, because from ballpark numbers arb might not be the best idea, i think the above could be brilliant to spin up the following for builders: when you deploy on arb, if your protocol generates a certain type of traffic, you get a share of the revenue of the whole chain.

And while this could potentially be a compliance and organization nightmare, could also be one of the things that creates a new narrative, not seen at scale, in our industry.


So @JoJo you mean ,
This isn’t a distant vision. It’s unfolding now and you’re invited to shape the and revamp it ?

Here, your traffic doesn’t just flow—it cascades back to you. Every byte of data your protocol generates becomes a yield. It’s not mere profit-sharing; it’s profit-proliferation.

Is this crafting a constellation of success? Investors aren’t just backing your project; they’re buying and taping into an entire and potential.

i understand your perspective.

Challenges exist, they’re opportunities in disguise. Tackling compliance head-on isn’t a burden—it’s your competitive edge. While others hesitate, you’ll be pioneering paths and setting industry standards.

you’re shaping its future.

This isn’t just a call to action—it’s turning builders into stakeholders, protocols into profit centers, and challenges into catalysts.

Don’t just deploy. other are looking at us
Don’t just participate. Pioneer.
Don’t just code. Co-create the future.

it defines an era.

As the blockchain sector matures, platforms may become of interest to a broader range of investors and institutions.

Compliance-First Approach:
Arbitrum’s commitment to regulatory compliance sets it apart in the blockchain space. By proactively addressing regulatory requirements and working closely with authorities, Arbitrum aims to create a safe and secure environment for users, developers, and investors alike. This compliance-first approach positions Arbitrum favorably as the industry navigates an increasingly complex regulatory landscape.

Transparent Governance and Operations:
Transparency and accountability are core values in the Arbitrum ecosystem. The platform’s governance model is designed to be community-driven, ensuring that all stakeholders have a voice in shaping its future. Regular audits, open communication, and clear governance structures demonstrate Arbitrum’s commitment to operating in a transparent and trustworthy manner.

Driving Industry Maturation:
Arbitrum’s focus on compliance and transparency contributes to the overall maturation of the blockchain sector. By setting high standards for security, accountability, and regulatory adherence, Arbitrum is helping to bridge the gap between traditional finance and the emerging world of decentralized technologies. As more institutional investors and mainstream users engage with blockchain, platforms like Arbitrum will play a crucial role in building trust and fostering widespread adoption.

Investor Appeal:
For investors seeking exposure to the growth potential of blockchain technology, Arbitrum presents a compelling opportunity. The platform’s commitment to compliance and transparency aligns with the expectations of institutional investors and risk-averse individuals. By investing in projects built on Arbitrum, investors can participate in the blockchain revolution while mitigating the risks associated with unregulated or opaque platforms.

Moreover,the focus on scalability and efficiency opens up new possibilities for decentralized applications across various sectors, such as finance, supply chain management, and healthcare. As these industries increasingly embrace blockchain solutions, projects are well-positioned to capture market share and generate long-term value for investors.

Arbitrum represents a significant step forward in the evolution of blockchain technology. By prioritizing compliance, transparency, and community governance, Arbitrum is laying the foundation for a more mature, trustworthy, and accessible blockchain ecosystem. For investors seeking to capitalize on the growth potential of this transformative technology, Arbitrum offers a compelling opportunity to invest in a compliant, transparent, and innovative platform.


If, according to your plan, the treasury still needs to operate for up to a dozen more years to finally achieve linear release and bring rights to holders, what is the current function of the ARB token? Is it for voting or just a tool for the team to raise funds? Everyone is well aware of who holds absolute power, which leads to retail investors’ indifference towards voting rights. If this situation continues, why issue ARB? If you can take money from your own pocket during the next token incentive to offset the token sell pressure from monthly team and VC unlocks, as well as ecosystem incentives, then I would absolutely support your view. The formation of a “big government” mentality due to the ever-growing treasury and declining governance participation is what should be cautioned against


Does grounded governance models in general align with Offchain Labs’ MEV vision for Arbitrum? This requires a nuanced answer:Alignment in Principle, But Not a Direct Overlap:

  • Shared Values: The principles you outlined (contextual adaptation, trade-off analysis, experimentation, long-term vision) DO resonate with Offchain Labs’ commitment to thoughtful and community-driven development.
  • MEV is Specific: However, MEV (Maximal Extractable Value) is a very specific aspect of blockchain design. It’s about how value is captured from the ordering and inclusion of transactions.
  • Governance is Broader: Governance models, while influencing MEV, encompass a much wider range of decisions: treasury management, protocol upgrades, community grants, and more.

How They Intersect:

  1. MEV Revenue as a Governance Lever: Offchain Labs clearly wants to capture MEV to benefit the Arbitrum DAO. This revenue stream BECOMES a factor in governance:
  • How should it be allocated?
  • What should it be spent on?
  • Do token holders get a say?
  1. Governance Mechanisms Impact MEV Extraction:
  • Different voting systems might favor certain stakeholders who have more (or less) ability to extract MEV.
  • Transparency around governance can reduce the information asymmetry that MEV searchers often exploit.

In Conclusion:

  • Offchain Labs’ MEV vision creates a subset of challenges that mathematically sound governance can help address.
  • Simply having advanced governance models does NOT guarantee alignment with their MEV goals. The specific design and implementation are what matter.
  • It’s MORE about how those models are used to:
    • Fairly distribute MEV benefits
    • Prevent harmful MEV extraction that harms users
    • Maintain a transparent and predictable playing field for all participants.

Your original analysis is valuable because it provides a toolkit for thinking about these complexities. Now, the discussion needs to shift towards how those tools are applied specifically within the context of Arbitrum’s MEV goals.

1 Like

We believe this a multi-faceted proposal that represents a significant shift in MEV management and presents a valuable opportunity for Arbitrum.

1. Economic & Technical

The current First-Come First-Serve ordering model is flawed, due to its excessive enablement of MEV Searchers and its failure to capture value. The potential implementation of this proposal would enable the introduction of Timeboost, which allows MEV extraction but in a manner that protects network users and is more efficient at capturing value.

The implementation of this proposal would thus allow Arbitrum to meaningfully innovate on transaction ordering while expanding its set of value-accruing mechanisms.

2. Values, Ethos and Users First
Furthermore, Arbitrum’s long-term goal and premise is to arguably circumvent and build upon the ‘shortcomings and pitfalls’ of Ethereum, where maximally extractive activities like sandwich trades and frontrunning profoundly harm and impede user experience.

The implementation of this proposal is aligned with the core values of Arbitrum while solving an important pitfall in the user experience of many crypto users.

3. Value-accrual and Distribution
Although exact revenue estimates are challenging, Timeboost is expected to become another revenue-generating source for Arbitrum without compromising user experience. That is undoubtedly another great step forward which enhances Arbitrum’s long-term sustainability and viability.

How the newly captured and accrued value is distributed, is a nuanced topic that may require a separate vote, due to the sheer amount of inputs and debates that typically surround value-distributing mechanism proposals (buyback & burn, rev-share to all ARB holders vs. to ARB stakers, distributing ARB vs. ETH, etc.).

Individuals may agree with and be in favour of the implementation and adoption of Timeboost, but may not necessarily agree with and be in favour of any of the proposed value-distributing mechanisms.

In the context of the current options proposed, we find Option 1 (collect ETH) to be the superior option.

At this point in time, the token ‘burning’ mechanism has been sufficiently time and battle-tested. There have been various implementations of this mechanism across the industry. Yet, according to the existing data (both internal and external) today, it is clear that from a purely economic perspective, none of its implementations tend to fundamentally and efficiently drive value to the underlying token.

From a legal/regulatory perspective, the ‘buyback and burn’ mechanisms have been deemed a more ‘compliant’ and viable solution, which is a common reason why many protocols and initiatives still decide to adopt this approach, despite its subpar economic performance.

However, the legal and regulatory landscapes are continuously evolving and changing, while the fundamentals and economics do not. That is why we find Option 1 (collect ETH) to be a superior option.

Additionally, besides the pure assessment of the proposal itself, Express Lane appears to be greatly similar to Fast Lane on Polygon and hence it could be efficient and worthwhile for the two teams to connect and collaborate.


This is an exciting proposal!

Regarding choosing the right option (burn ARB or receive ETH), my belief is that this need to be evaluated having in mind a broader discussion about DAO’s spending budget, runway, and treasury management strategy. Having to choose now, I would say that option 1 is better, as is an extra revenue stream to the DAO, that can later decide how to use that to foster growth and perpetuity.

1 Like