TLDR
- Arbitrum has activated ArbOS 40 which brings the Ethereum Pectra Upgrade to its layer-2 network.
- The upgrade includes EIP-7702 which enables smart account features like batching and sub-key permissions.
- ArbOS 40 adds EIP-2537 which improves zk proof operations with native BLS12-381 precompiles.
- The update also includes EIP-2935 allowing access to recent block hashes on Arbitrum chains.
- Developers benefit from a Stylus VM fix that improves Rust-based contract performance and reliability.
Arbitrum has integrated the Ethereum Pectra Upgrade through its latest ArbOS 40 “Callisto” deployment. This major enhancement is now active on Arbitrum One and Nova. It introduces account abstraction, zk tooling, and developer-focused improvements to Ethereum’s largest layer-2 ecosystem.
The ArbOS 40 upgrade aligns Arbitrum with Pectra, Ethereum’s mainnet hard fork activated on May 7, 2025, at epoch 364032. Pectra brought several Ethereum Improvement Proposals (EIPs) to improve user accounts and L2 compatibility. With ArbOS 40, these upgrades now benefit the Arbitrum network’s performance, utility, and scalability.
By leveraging EIPs from Pectra, Arbitrum strengthens its infrastructure for smart accounts, validator tools, and more efficient data operations. The Ethereum Pectra Upgrade is reshaping how developers and applications function across the layer-2 environment. Arbitrum’s update ensures developers can now access new primitives across all supported chains.
EIP-7702 Enables Smart Account Features on Arbitrum
The integration of EIP-7702 introduces executable code within EOAs during a transaction on Arbitrum. This allows features such as transaction batching, sponsored fees, and permissioned sub-keys on layer-2. Developers and users gain immediate benefits from these expanded account capabilities.
This advancement marks a shift in Ethereum account functionality, which is now usable through Arbitrum’s ecosystem. The Ethereum Pectra Upgrade makes these tools available at scale on layer-2 chains. Arbitrum chains can now support advanced use cases with minimal friction.
ArbOS 40 applies these changes to all Arbitrum environments. Developers can test, deploy, and maintain abstraction-enabled smart accounts on Arbitrum One and Nova. The rollout also provides native support for these features across dApps.
Pectra is now live on Arbitrum!
Builders can now access one-click swaps, gas sponsorships, and more
More UX. More innovation. Arbitrum Everywhere pic.twitter.com/Kksgl6DKma
— Arbitrum (@arbitrum) June 18, 2025
EIP-2537 and EIP-2935 Improve zk Tools and Trustless Access
EIP-2537 introduces BLS12-381 precompiles, enhancing zk proof compatibility and signature validation speed. This benefits zero-knowledge rollups operating on Arbitrum. By adding BLS-native operations, the Ethereum Pectra Upgrade enhances trust and efficiency.
ArbOS 40 includes EIP-2935, which gives access to recent L2 block hashes. This supports stateless clients, oracles, and verifiable messaging protocols. Developers can now build more reliable applications using past data directly.
A Stylus VM fix also improves Rust-based development by resolving cache lookup issues. The Ethereum Pectra Upgrade ensures improved tooling for all builders. Arbitrum’s alignment with Ethereum upgrades advances the network’s scalability mission.
