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ArbOS 30 Bianca

Note to Orbit chains

Upgrading your Orbit chain to ArbOS 30 or deploying a new Orbit chain with ArbOS 30 is not yet supported or encouraged. This page will be updated with requirements, upgrade instructions, and associated details when available. When ArbOS 30 Bianca is ready for Orbit mainnet adoption and all requirements have been formally tagged and published, Orbit chain owners and RaaS teams will need to follow these instructions to upgrade. When the time comes, Orbit chain owners will need to upgrade their Nitro node versions, deploy new versions of nitro-contracts (using the Orbit action contracts), set a new Wasm module root, and perform any ArbOS 30 Bianca specific configurations or actions.

ArbOS 30 Bianca will be shipped as a Nitro release, which will be available on Docker hub. For Arbitrum One and Arbitrum Nova, the ArbOS 30 Bianca upgrade requires a governance vote to activate and so this release of Nitro will be a mandatory upgrade for Arbitrum One and Nova node operators if the on-chain DAO vote for the upgrade proposal passes. The Arbitrum docs will remain the canonical home for information regarding ArbOS releases, with more details found on the ArbOS Software Releases Overview page.

Requirements:​

  • A minimum Nitro version of 3.0.0, but the exact version is yet to be tagged and released.
  • An upgrade to a new, unreleased version of nitro-contracts
  • The setting of a new Wasm module root (that will be added here when available)

High-level description of ArbOS 30 changes​

ArbOS 30 Bianca is a major upgrade for Arbitrum chains and ArbOS upgrades can be seen as Arbitrum’s equivalent of a hard fork - more can be read about the subject over in Arbitrum ArbOS upgrades. Please note that ArbOS 30 Bianca is an upgrade that builds upon ArbOS 20 Atlas.

ArbOS 30 Bianca brings many features, improvements, and bug fixes to Arbitrum chains. The full list of changes can be found in the Nitro release notes for Nitro 3.0.0 or higher (as Nitro 3.0.0 is the first Nitro version that adds support for ArbOS 30 Bianca). Highlighted below are a few of the most impactful and critical features that are introduced with ArbOS 30:

  • Activation of Stylus on Arbitrum chains through the addition of a new WebAssembly-based virtual machine that runs alongside the EVM. Stylus enables developers to write smart contracts in new programming languages that compile down to WASM, like Rust, that are more efficient and safer than Solidity smart contracts while retaining complete interoperability.
  • Adoption of RIP-7212, a precompile for verifying the Secp256r1 or P-256 curve on Arbitrum chains. Adding support for this precompile allows account abstraction wallets to cheaply verify a type of signature widely used in passkeys and secure enclaves.
  • V0 support for Arbitrum Nitro node snap sync, enabling a Nitro node to sync from a snapshot already accepted from L1 through the propagation of blockstate from other nodes in the network.
  • A change to the transaction fee router contracts on Arbitrum Nova to allow for fees collected to be automatically sent to the ArbitrumDAO Treasury on Arbitrum One. Currently, the ArbitrumDAO receives Arbitrum Nova transaction fees are sent to a ArbitrumDAO controlled address that requires a constitutional proposal to move, which is less efficient. This change is specific to Arbitrum Nova and is not expected to impact Orbit chains.