UPDATE AS OF JUNE 19, 2026
This proposal has been updated with two important changes. See the June 19, 2026 update section for full details.
UPDATE AS OF MAY 6, 2026
At the time of writing, Offchain Labs, in close collaboration with Entropy Advisors, had not yet concluded our detailed analyses on a new set of multidimensional gas targets to use for Dynamic Pricing. As a result, we proposed to leave Dynamic Pricing disabled as part of ArbOS 60 Elara’s activation on Arbitrum One and Arbitrum Nova.
Update — June 19, 2026
Offchain Labs would like to make 2 important updates to this proposal, alongside the in-line edits to reflect these updates.
Update 1: Minor version bump from ArbOS 60 to ArbOS 61
During testing of ArbOS 60 on Arbitrum Sepolia, an issue was reported by an ecosystem partner and subsequently confirmed by Offchain Labs: due to two interacting bugs in the gas refund logic, the upgrade caused small, unintended changes to gas refund behavior relating to Dynamic Pricing even with Dynamic Pricing disabled. Unfortunately, the required fixes modify the State Transition Function (STF) and therefore can only be applied via a new ArbOS version. The corrected release is versioned as ArbOS 61. ArbOS 61 is otherwise identical in scope to the ArbOS 60 Elara proposal described below - no features, parameters, or permissions have changed — and all references to ArbOS 60 in this proposal have been updated to read as ArbOS 61. Arbitrum One and Arbitrum Nova were never affected, as ArbOS 60 was not activated on either chain. Arbitrum Sepolia will be upgraded to ArbOS 61 once final release testing is complete. Node operators will be notified beforehand to give adequate time to upgrade their Nitro node software versions.
Update 2: Reaffirming our decision to not activate Dynamic Pricing as part of this proposal
Entropy Advisors has now concluded the analysis on the impacts of Dynamic Pricing (formally: multidimensional gas) on Arbitrum One, referenced in our May 6 update. The findings from the analysis, coupled with the below facts from our own internal assessment of the current implementation, were what ultimately led to our decision to leave Dynamic Pricing disabled and inactive on Arbitrum One and Nova.
See Entropy Advisor’s full analysis here: [Constitutional] AIP: ArbOS 61 Elara - #22 by Entropy
Our own internal assessment of the current implementation concluded that:
- Activating Dynamic Pricing on Arbitrum One and Nova would add additional code complexity to the Nitro node software. While normally this is not a concern in isolation, we hypothesize that Ethereum’s own specification for multidimensional gas (starting with EIP-8037, which is scheduled for the 2026 Glamsterdam hard fork) will result in a bigger Geth diff than we’d like if we enable implementation of multidimensional gas pricing, resulting in a larger long term maintenance burden when compared to adopting what Ethereum eventually pursues. It is our preference to, therefore, invest more time and effort into ensuring that our implementation be updated in such a way that allows Arbitrum chains to reap the many benefits of a multidimensional gas pricing regime, while minimizing the differences between how we implement it and how Ethereum eventually implements it.
- There are non-trivial performance tradeoffs relating to the per-transaction overhead that the new gas accounting logic would impart on chains running at 100ms blocktimes. While today Arbitrum One and Nova do not themselves run at 100ms blocktimes, we have a strong preference to take the time to optimize and invest further in our implementation such that the performance and stability differences between Arbitrum chains running at 100ms vs. 250ms blocktimes are smaller.
- Dynamic Pricing Pricing is only one of many possible and exciting solutions to consider when scaling Arbitrum technology and we believe, especially given the above two points, that there are other solutions that have similar or greater impact with more palpable and less significant tradeoffs. In other words: we believe there are higher return-on-investment solutions we can invest in in the short term instead. We’re very excited to share those with the Arbitrum community when we’re ready to!
All in all, we intend to leave this codepath in the codebase but keep it disabled for Arbitrum One and Nova. This is done so intentionally so that our team has the option to pick this back up in the future should a scenario arise where we believe it makes appropriate sense to re-assess the benefits and tradeoffs. Explicitly: the ArbOS 61 proposal payload will be updated to exclude both: the requisite ArbOwner() call to enable Dynamic Pricing and the access list (implemented via the ResourceConstraintManager smart contract) used grant Offchain Labs the special rights relating to controlling and setting the Dynamic Pricing parameters. In other words: we are no longer requesting the ArbitrumDAO to grant special privileges to Offchain Labs to modify the Dynamic Pricing parameters, because Dynamic Pricing itself is no longer being proposed to get activated as part of this proposal.
We want to extend a sincere thank you to Entropy Advisors, who were exceptional partners throughout this analysis and thought partners on the decision itself.
Abstract
This AIP proposes to upgrade Arbitrum One and Arbitrum Nova to ArbOS 61 Elara. This upgrade includes several innovative Arbitrum features and changes - all of which represent the culmination of months of research and engineering from the Offchain Labs team and is in response to invaluable feedback from the Arbitrum ecosystem of partners, developers, and users. At a high level, the changes being introduced in ArbOS 61 Elara are as follows:
- Increased smart contract code size limit of 96 KB for Stylus smart contracts and accompanying changes to the Stylus Rust SDK to take advantage of this new limit, which is 4x greater than the smart contract size limit for Solidity contracts on the EVM.
- A change to allow Offchain Labs, as a service provider to The Arbitrum Foundation on behalf of, and for the benefit of, the ArbitrumDAO, to modify the minimum L2 base fee on Arbitrum One and Nova, between 0.01 gwei and 0.10 gwei (inclusive). This would be enabled via a new
BaseFeeManagercontract, in a similar way to theResourceConstraintManagercontract (previously proposed here and activated alongside ArbOS 51 Dia).
Additionally, the below features will be included in ArbOS 61 for the convenience of other Arbitrum chains, but are left intentionally disabled on Arbitrum One and Nova:
- The long awaited API for Arbitrum chains to more cleanly interface and leverage Alternative Data Availability (AltDA) Layers. Arbitrum One and Nova are not expected to leverage this API since these two DAO-owned chains settle to Ethereum.
- An optional feature for chain owners to restrict on-chain activity from specific, pre-identified addresses. This feature is primarily meant for Arbitrum chains that need to comply with certain regulatory requirements. This feature, however, will not be enabled on Arbitrum One or Nova as part of this proposal.
- An optional feature that allows chain operators to collect priority fees from transactions. Historically, users have been able to specify a priority fee, but Arbitrum chains are not configured to accepted them. This proposed change would introduce the ability for chains to enable tip collection and use priority fees to influence transaction ordering and inclusion. This feature will not be enabled on Arbitrum One or Nova as part of this proposal and would require a separate governance action to activate.
While the goal of the proposed ArbOS 61 Elara upgrade is to eventually be available for adoption by any Arbitrum Chain, this proposal only concerns the Arbitrum One and Arbitrum Nova chains, as these two chains are governed by the ArbitrumDAO. At a high level, an ArbOS upgrade can be interpreted as Arbitrum’s equivalent of a hard fork - more can be read about the subject here.
Please note that ArbOS Version 61 Elara is a proposed upgrade that builds upon ArbOS 51 Dia, which has been previously adopted by the ArbitrumDAO.
These upgrades and delegated rights are proposed by Offchain Labs in its role as an Arbitrum Aligned Entity (AAE), as described in A Vision for the Future of Arbitrum. Offchain Labs serves as an AAE for engineering, product, business development, and technical research.
Specification & rationales of proposed changes
1. Increased Stylus smart contract code size limit to 96 KB
As mentioned in our reply to another forum post, we are proposing an increase to the Stylus smart contract code size limit to 96 KB, up from 24 KB (a 300% increase). This increase will accompany a new version of the Stylus Rust SDK to make use of this new limit.
This increase is enabled by changing how Stylus contracts are deployed and activated. Specifically, when a contract larger than 24 KB is deployed, the Stylus Rust SDK will split the contract into multiple fragments that are each within the regular 24 KB contract size limit alongside the deployment of a special stylus-collection contract that contains a mapping to each fragment. Upon successful activation, the State Transition Function (STF) within the Arbitrum node software will read all fragments using the stylus-collection contract, append their contents before decompression, and from that point, treat the collection of fragments as one contract.
Rationale
Arbitrum Stylus was launched with the same code size limit as Solidity contracts (24 KB) to maximize interoperability between Solidity and Stylus smart contracts (i.e. they can call into one another) and reduce the technical differences for Solidity developers moving over to try Stylus.
As teams began pushing the boundaries of what’s possible with Stylus, particularly by leveraging Rust libraries through the first-party SDK and the broader Rust ecosystem, the 24KB limit became more constraining for Stylus programs than it typically is for Solidity contracts. This has introduced a lot of friction in the overall developer experience and added unnecessary complexity for teams building larger and scalable applications.
This change is limited to Stylus applications only. Increasing the size limit for Solidity contracts would alter core EVM assumptions and introduce a divergence from Ethereum’s contract size rules, with potential impacts on node performance, developer tooling, and cross-chain compatibility. For those reasons, modifying the Solidity limit is not included part of this proposal and so the proposed scope is intended only to help unblock Stylus development and growth.
2. Changes to how the minimum base fees can be modified & who can modify them
The last part of ArbOS 61 Elara that applies to Arbitrum One and Nova is a proposal to grant Offchain Labs the privilege of modifying the minimum L2 base fee on Arbitrum One and Nova to any value between 0.01 gwei and 0.10 gwei, inclusive. If this proposal passes, this privilege will expire after a 2 year period, as measured from the mainnet activation of this proposal. This approach ensures that subsequent changes to the minimum L2 base fee by Offchain Labs on behalf of the Arbitrum DAO does not need to go through a lengthly Constitutional Vote that normally takes 30+ days. Note that as of January 8, 2026, the minimum L2 base fee on Arbitrum One and Nova was changed to 0.02 gwei as part of the ArbOS 51 Dia upgrade.
Rationale
The minimum L2 base fee is an integral economic aspect of Arbitrum One and Nova. Changes to this value can have a direct impact on the prevalence of spam and transaction fee-based revenue to the Arbitrum DAO, as mentioned in the previous successful AIP to raise the minimum L2 base fee from 0.01 gwei/gas to 0.02 gwei/gas.
With the recent introduction of a new L2 pricing algorithm in ArbOS 51 Dia and yet another upgrade to the L2 pricing algorithm with Dynamic Pricing (this proposal), the cost to transact on Arbitrum One and Nova has fallen and will continue to fall - especially during periods of elevated demand. This is naturally a boon for users and developers but puts a strain on the Arbitrum DAO’s ability to continue investing in growth via incentives, grants, and investments.
In our capacity as an Arbitrum Aligned Entity (AAE), as described in A Vision for the Future of Arbitrum, and in close collaboration with other AAEs (like Entropy Advisors) and ecosystem partners, we believe that this privilege will allow us to quickly iterate, model and ultimately strike the right balance between growing organic activity, long-term ArbitrumDAO financial sustainability, managing spam, and preserving capital efficient DeFi markets. In other words, our goal is to find the right equilibrium through iteration that ultimately leads to a static, final minimum L2 base fee without negatively impacting Arbitrum One and Nova’s thriving ecosystem of users, builders, and node operators.
Any change that is made will follow a public notification via forum post to ensure the ArbitrumDAO has 100% transparency into any modifications that are being made, similar to how Offchain Labs informed the Arbitrum DAO on the recent reserve price changes for Timeboost. As always, the ArbitrumDAO retains the right to remove the delegation of this power to OCL to act via the standard governance process at any time.
Base Fee Manager contract
There will be a new contract deployed called the BaseFeeManager that will give Offchain Labs the appropriate permissions to adjust mininumL2BaseFee and L2BaseFee values from 0.01 gwei and 0.10 gwei, inclusive. The BaseFeeManager contract will contain an access list. We propose that the ArbitrumDAO use this access list to designate Offchain Labs the right to adjust the mininumL2BaseFee and L2BaseFee values in accordance with the terms hereof.
This new contract will be audited by an independent third party entity (Trail of Bits). A full audit report will be published alongside this proposal when it gets proposed in the eventual on-chain vote. Implementing this BaseFeeManager contract will allow Offchain Labs to adjust these values, within the proposed bounds set forth herein, without the need for additional votes - should the ArbitrumDAO pass this proposal.
3. A minor bug fix involving the STF, resulting in a version bump from ArbOS 60 to ArbOS 61
During testing of ArbOS 60 on Arbitrum Sepolia, an issue was reported by an ecosystem partner and subsequently confirmed by Offchain Labs: due to two interacting bugs in the gas refund logic, the upgrade caused small, unintended changes to gas refund behavior relating to Dynamic Pricing even with Dynamic Pricing disabled. Unfortunately, the required fixes modify the State Transition Function (STF) and therefore can only be applied via a new ArbOS version. The corrected release is versioned as ArbOS 61. ArbOS 61 is otherwise identical in scope to the ArbOS 60 Elara proposal described below — no features, parameters, or permissions have changed — and all references to ArbOS 60 in this proposal have been updated to read as ArbOS 61. Arbitrum One and Arbitrum Nova were never affected, as ArbOS 60 was not activated on either chain. Arbitrum Sepolia will be upgraded to ArbOS 61 once final release testing is complete. Node operators will be notified beforehand to give adequate time to upgrade their Nitro node software versions.
Other features included in ArbOS 61 but not enabled on Arbitrum One
Alternative Data Availability (AltDA) Layer API
In ArbOS 61, a new pluggable interface to the Arbitrum node software will be introduced that enables AltDA Layers (e.g. EigenDA, Celestia, etc) to integrate with an Arbitrum chain without the need to fork the Arbitrum node software. This API, once integrated by a chain owner, will also reduce the technical overhead and complexities associated with maintaining existing forks of Nitro that are being used to run Arbitrum chains on AltDA layers. For more information, refer to the integration guide.
While this interface is not intended or proposed to be used by Arbitrum One or Nova, its inclusion in ArbOS 61 Elara is intended to simplify the codebase and canonicalize this feature in Nitro. This feature is instead intended to be used by Arbitrum chains who integrate with Data Availability (DA) layers that are not Ethereum, other Arbitrum L2s, or an AnyTrust DAC.
Compliance transaction filtering
ArbOS 61 Elara will also include new, optional components that can be enabled in the Sequencer and State Transition Function (STF) to allow for protocol-level transaction filtering for regulatory or compliance purposes, at the discretion of the chain owner. The chain owner may configure an external compliance service (e.g., TRM or Chainalysis) to define address-level policies. Any transaction that originates from, targets, or otherwise involves a restricted address is filtered prior to execution, including transactions submitted via the Delayed Inbox.
While this feature is not intended or proposed to be used by Arbitrum One or Nova, its inclusion in ArbOS 61 Elara is intended to simplify the codebase and canonicalize this feature in the node software. This feature is instead intended to be used by Arbitrum chains who have compliance and regulatory obligations to restrict on-chain activity from sanctioned entities or actors.
Priority Fees
ArbOS 61 introduces a way to enable the collection of tips in the form of priority fees on an Arbitrum chain. However, the actual enablement of this feature (i.e. turning it on) on Arbitrum One and Nova is not proposed for this vote or upgrade and will instead require an additional Constitutional DAO vote sometime in the future. Today priority fees are not collected, and the feature to collect tips remains disabled, meaning that if a transaction includes priority fees they won’t be collected. The proposed change simply adds the capability for Arbitrum Chain operators to later enable tip collection and use priority fees as an input to transaction ordering. Any Arbitrum Chain that wants to order transactions based on priority fees would need to both enable tip collection and update the Sequencer’s sorting logic to incorporate the PriorityFee field.
4. WASM Compatibility Changes
This upgrade includes several bug fixes and improvements to Stylus. It also removes support for the WebAssembly multi-value extension, simplifying the execution model. Contracts relying on multi-value WASM will no longer be able to be activated or re-activated.
Steps to Implement & Timeline
More detailed information about the specific implementation and versions will be provided closer to the date of the formal on-chain vote. However, this proposal will roughly follow the steps below:
- An AIP outlining the proposed upgrade and specification is proposed to the ArbitrumDAO forum for discussion (this post);
- Engineering work to scope out and implement the relevant changes for ArbOS 61 Elara into the Arbitrum node software, relevant rollup contracts, and associated upgrade actions (this work has already begun);
- A security audit of all ArbOS 61 Elara relevant changes is conducted by a third-party (Trail of Bits) and the audit report is published for public consumption;
- A temperature check vote is held on Snapshot;
- A new version of Nitro and nitro-contracts, if necessary, are released that support ArbOS 61 Elara;
- Should the Snapshot vote pass, ArbOS 61 Elara will be deployed to both private devnets & Arbitrum Sepolia for testing;
- A formal AIP is proposed for an on-chain vote;
- If the on-chain vote passes, ArbOS 61 Elara will be activated on Arbitrum One and on Arbitrum Nova following the required waiting periods and phases, as outlined in the ArbitrumDAO Constitution.
Overall Cost
This proposal comes at no cost to the ArbitrumDAO as the engineering work and coordination for an audit will be owned by Offchain Labs.

