Caldera supports Decentralized Sequencing via an integration with Espresso, a premier decentralized sequencing network.

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Why Decentralized Sequencing?

Every rollup relies on a sequencer to order and verify the transactions on the chain. Traditionally, these sequencers have been centralized entities, controlled by a single party or group of parties. The vast majority of rollups currently in production (including Arbitrum One, Optimism mainnet, Base, and zkSync, among others) currently utilize a centralized sequencer.

These rollups are still able to inherit the security properties of their underlying chain via rollup proof systems, but their centralized sequencers still pose several problems:

• Centralized sequencers create a single point of failure in the system. If the sequencer goes down, it can become impossible or prohibitively expensive to submit transactions for inclusion

• The centralized sequencer can arbitrarily censor or delay transactions, or reorder transactions to extract MEV

• Users do not have visibility into how transactions are ordered

The status quo requires users to place some trust in rollup operators: users must trust that the operator will keep the sequencer online, trust that the sequencer orders transactions according to spec, and trust that the operator is not extracting MEV from the chain or arbitrarily censoring transactions.

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How it Works

At a high level, the Espresso Sequencer network replaces the rollup’s mempool implementation. User transactions are sent to the Espresso Sequencer rather than the rollup node itself. Then, rollup nodes query sequenced transactions from Espresso’s sequencer node. This eliminates the dependence on a centralized sequencer to act fairly.

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Integrate with Espresso

We’re excited to work with teams exploring rollups with decentralized sequencing. Please get in touch!