Arbitrum Activates ArbOS 61 Elara With Optional Compliance Filters for Orbit Chains

Arbitrum has activated its ArbOS 61 Elara protocol upgrade, introducing optional compliance filtering tools for Orbit chains while leaving priority fees on Arbitrum One disabled pending a separate governance vote.

Orbit chains are dedicated, application-specific networks built on top of the Arbitrum stack. Under the Elara upgrade, operators of those chains can now implement transaction screening mechanisms at the chain level. The key structural detail is who controls that switch: individual chain owners, not ArbitrumDAO, decide whether to activate compliance filters on their networks. The base Arbitrum One network is unaffected by any screening changes.

Chain owners, not ArbitrumDAO, control screening on dedicated networks, while priority fees remain off on Arbitrum One pending another vote.

That separation is deliberate. By keeping compliance tooling optional and confined to dedicated deployments, Arbitrum positions the upgrade as an institutional onramp rather than a protocol-wide policy shift. Enterprises and regulated entities building on Orbit chains can configure screening to satisfy local regulatory requirements without those rules propagating to the broader Arbitrum network.

Elara expands configuration options for Orbit chain operators, giving teams more granular control over how their chains handle transactions and fees. On Arbitrum One itself, the most consequential pending change, enabling priority fees, still requires a separate ArbitrumDAO governance vote before it can go live. Priority fees, common on other networks, allow users to pay a premium for faster transaction inclusion and represent a meaningful revenue stream for validators and the protocol treasury.

Arbitrum has shipped regular ArbOS updates over the past two years as competition among Ethereum Layer 2 networks intensified. The compliance angle in Elara marks a more pointed acknowledgment of institutional pressure. Since late 2024, major Layer 2 operators have faced increasing questions from regulators and enterprise clients about how permissioned activity can coexist with public blockchain infrastructure. Arbitrum's answer with Elara is to push that decision down to the chain-owner level, preserving permissionlessness at the protocol layer while giving individual deployments the tools to meet their own compliance obligations.

Critics of the approach argue that even optional compliance filters introduce fragmentation. If Orbit chains adopt divergent screening standards, developers and users moving between those chains could face inconsistent experiences, and the broader Arbitrum network effect could weaken. There is also a philosophical objection: any mechanism that allows a chain operator to block or screen transactions cuts against the permissionless ethos that defines public blockchains. Supporters counter that the optionality itself is the point. No Orbit chain is required to activate screening, and Arbitrum One remains open.

The disabled priority fees on Arbitrum One add a separate layer of uncertainty. Without them, the protocol foregoes a fee revenue stream that comparable networks already collect. Whether ArbitrumDAO moves to enable them in a near-term vote will signal how aggressively the network intends to compete on sustainability metrics alongside technical ones.