[CONSTITUTIONAL] AIP: ArbOS Version 40 Callisto

[jameskbh]

Hello! Thanks for this exciting news!

I have a few questions:

• About the process itself, can you clarify the difference between steps 2 and 6? I’m assuming this is the same vote (step 2), correct? And the steps 3-6 will follow that.

@Arbitrum

• An AIP outlining the proposed upgrade and specification is proposed to the ArbitrumDAO Forum for discussion (this post)
• A temperature check vote is held on Snapshot
• Engineering work to scope out and implement the relevant changes for ArbOS 40 Callisto into the Nitro node software, relevant rollup contracts, and associated upgrade actions (this work has already begun).
• A security audit of all ArbOS 40 relevant changes is conducted by a third-party (Trail of Bits) and the audit report is published for public consumption.
• A new version of Nitro and nitro-contracts is released that support ArbOS 40 Callisto.
• Should the Snapshot vote pass, then ArbOS 40 Callisto will be deployed to both private devnets & Arbitrum Sepolia for testing.
• A formal AIP and call-to-vote is proposed to Tally for the on-chain vote.
• If the Tally vote passes, ArbOS 40 Callisto will be activated on Arbitrum One and on Arbitrum Nova following the required waiting periods and phases, as outlined in the ArbitrumDAO Constitution for a Constitutional AIP.

About the timeline

@Arbitrum

Given that the L1 client teams are planning to release their Pectra-supported versions by Feb 13, 2025 and that the required steps for a Constitutional AIP can take up to ~41.4 days (not including engineering and audit), there is a strong likelihood that ArbOS 40 Callisto will be activated on Arbitrum One and Arbitrum Nova after Ethereum Mainnet upgrades to Pectra (if the ArbitrumDAO votes to adopt this proposal).

• Do you have an update regarding the releases that were supposed to happen on Feb 13th?
• This sentence: “there is a strong likelihood that ArbOS 40 Callisto will be activated on Arbitrum One and Arbitrum Nova after Ethereum Mainnet upgrades to Pectra (if the ArbitrumDAO votes to adopt this proposal).” is mere informative or there is anything we should be aware of?