Optimism core developers at OP Labs successfully activated the Isthmus hardfork today, bringing key features from Ethereum’s Pectra upgrade to the OP Stack and the Superchain. The upgrade comes just two days after Pectra went live on Ethereum, making the Superchain the first L2 ecosystem to support Pectra.

Included in this upgrade is Base, Ink, OP Mainnet, Soneium, Unichain, and several other OP Stack chains. The Superchain powered nearly 70% of all L2 activity in April (measured by transaction fees), and every OP Chain in the Superchain contributes revenue back to the Optimism Collective in exchange for shared governance, security and upgrades - Pectra being a prime example.

The OP Stack has become a standard for L2 infrastructure, supporting 12.3 million daily transactions in April. Its open source, MIT-licensed architecture supports innovation and flexibility, and allows for shared upgrades to quickly activate across a vast and growing ecosystem of chains.

The OP Stack’s core design principles prioritize EVM equivalence and minimal code difference from Ethereum L1 execution clients, enabling Optimism to easily upstream new features and functionality released on L1. The stack stays almost identical to Ethereum, so every core upgrade flows straight into the Superchain, not months later.

Only with the OP Stack can L2 developers and users now immediately benefit from Ethereum’s improvements, just 48 hours after launch.

Pectra’s big unlocks for the Superchain

Blockchains are growing, and with greater adoption comes scaling issues and high transaction costs. Thanks to Pectra, OP Stack chains benefit from blob scaling and decreased fees. Pectra’s EIP-7702 brings account abstraction to life with significant UX improvements, benefitting users as adoption continues to accelerate.

It’s not just L2 chains that benefit from Pectra: 7702 in particular is a big unlock for Superchain apps, too. Smart wallet functionality is now available for all existing app users, simplifying multichain transactions and essentially creating a one-click trading experience. We expect DeFi apps across the Superchain to quickly adopt this, driving more activity by removing friction.

Ethereum’s Superchain: Looking ahead to further scale

While Pectra introduced significant improvements to the Ethereum network, there’s more work to be done. Scalability remains Ethereum’s most critical challenge, and L2s fundamentally need more scale. With current growth trajectories, even with Pectra’s 2x blob increase, L2s need a 5-8x increase in blob capacity for blobs to remain uncongested. Developers at OP Labs have proposed a solution through Blob-Parameter Only (BPO) forks.

We’re excited to further tackle this challenge through the upcoming Fusaka upgrade. Optimism has dedicated engineering resources to support PeerDAS, with the goal of driving stronger network reliability and scalability.

We continue to proudly support Ethereum as it evolves, and we’re building Ethereum’s Superchain to scale with it.

Join us in building with the OP Stack as part of the Superchain:

• Deploy a chain or app

• Build interoperable apps on Superchain devnet

• Apply for Retroactive Public Goods Funding: Onchain Builders

• Apply for a grant to cover your Superchain app audit