ArbOS 61 (Elara) is ready for adoption, and Conduit will be activating it on your chain on the dates below. This upgrade brings compliance transaction filtering and priority fee collection, and more.

Upgrade Highlights

• Compliance transaction filtering (optional): Optional protocol level filtering against an external policy service such as TRM or Chainalysis. Filtering happens at the sequencer and in the STF, including transactions submitted through the Delayed Inbox.

• Priority fee collection (optional): Chains can now collect tips as priority fees. Users could always set a priority fee, but no Arbitrum chain was configured to accept one, so the value was ignored.

• Gas refund fixes: Fixes two interacting bugs in the gas refund logic that caused small, unintended changes to gas refund behavior.

Good to Know

• These features are optional and need to be enabled on a per-chain basis, they won't be turned on as part of the upgrade. If you are interested in any of these features, do reach out.

• ArbOS 61 includes other changes that may affect your chain, your users, or contracts deployed on it. Please read the full upgrade notice before the upgrade.

Required Actions

• No action required if you are not running external nodes.

• If you or your partners are running external nodes:

  • You must upgrade your Nitro node's version tov3.11.4 (release link)

Readiness Schedule
You need to have your nodes upgraded before these dates: Thu 15th Oct 2026

Questions?
Drop us a message here — we're happy to help!