TLDR
- Optimism and Flashbots introduce advanced sequencing tools for the OP Stack to improve scalability.
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Flashblocks will provide 200ms confirmations on the Superchain, benefiting Ethereum Layer 2.
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The partnership aims to improve sequencing fairness, reduce spam, and capture MEV revenue.
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Flashbots’ tools offer customizable latency and scalability options for OP Stack builders.
Optimism has partnered with Flashbots to advance the sequencing capabilities of the OP Stack, a significant move aimed at improving chain differentiation, scalability, and revenue capture. The partnership will provide builders with access to new tools designed to enhance transaction speeds, fairness, and overall flexibility in the Superchain ecosystem.
The OP Stack, which powers various Ethereum Layer 2 networks like Base, Unichain, and Soneium, currently handles over 60% of all Ethereum Layer 2 activity. With this collaboration, Optimism aims to further solidify its position by enabling faster, more customizable transaction processing for developers.
Improved Sequencing Features for Builders
The main upgrade brought by this partnership is the integration of sequencing features already proven on Ethereum. Flashbots’ Flashblocks, which have been deployed on Base and Unichain, provide 200ms confirmations, drastically improving transaction finality speed. This feature will soon be expanded to the OP Mainnet and other Superchain networks.
Optimism is partnering with Flashbots to bring fast, verifiable sequencing to the Superchain 🔴
Faster confirmations = smoother user experience. pic.twitter.com/85NQQGSVBe
— Optimism (@Optimism) August 21, 2025
Additionally, builders will gain access to programmable block building, enabling them to customize the blocks according to their specific needs. This flexibility is especially valuable for projects aiming to optimize for latency or fairness in their respective use cases.
Focusing on MEV Capture and Fairness
Another key benefit of this partnership is the focus on responsible MEV (Maximal Extractable Value) capture. Flashbots’ technology allows for verifiable fairness, ensuring that transactions are handled securely and without bias.
This feature aims to reduce any potential manipulation of transaction order and improve the integrity of the network.
By integrating these features, the partnership addresses the issue of fairness in Layer 2 ecosystems, where sequencing can often be a source of controversy. Flashbots’ use of secure enclaves ensures that the system remains transparent and resistant to spam, improving overall network security.
What This Means for the Superchain Ecosystem
The Superchain is a collective term for the ecosystem of Layer 2 networks built on top of Ethereum, including Base, Unichain, and several others. As of August 2025, the Superchain is responsible for a significant portion of Ethereum’s Layer 2 activity.
Optimism’s collaboration with Flashbots will allow the Superchain to scale more efficiently while providing developers with the tools needed to ensure reliable performance.
“Through this partnership with Flashbots, we are accelerating the roadmap for fast, cheap, and customizable sequencing across the OP Stack,” said Sam McIngvale, Head of Product at OP Labs. He emphasized that this collaboration supports the broader mission of enabling builders to design their chains in ways that best suit their unique needs.
Optimism Vision for Open, Flexible Infrastructure
One of the overarching goals of this partnership is to create an open and flexible infrastructure that provides builders with the freedom to design their networks.
By using battle-tested technology, Optimism and Flashbots aim to make the OP Stack a robust and scalable solution for a wide variety of decentralized applications.
The integration of these advanced sequencing tools could set a new standard for transaction processing in Ethereum Layer 2 ecosystems. Builders will not only benefit from improved speed and scalability but also be able to capture more value within their own ecosystems.
