The Omni Rollup is a robust framework designed to facilitate cross-chain transactions across multiple Layer 1 (L1) blockchains within the Omnichain ecosystem. It deploys smart contracts on L1 chains that support them, managing transaction validation, state updates, and communication with the rollup. For L1 chains that do not support smart contracts, Omni Rollup uses direct addresses(vaults) to handle as set custody and processing. Execution with in the rollup can be configured in two ways: a shared execut or maintaining isolated states for each supported chain,ensuring resource optimization and centralized logic, or separate executors for each chain, which provide high isolation and allow chain-specific customizations.

At the core of its operation is the Omni Sequencer, a shared transaction coordinator responsible for organizing and ordering transactions. The sequencer collects transactions from various mempools and solvers, bundles them into batches, and determines a global order. A commitment for this order is created by hashing the ordered list of transaction bundles, producing a cryptographic digest that is published on a Data Availability (DA) layer. This commitment ensures that all participants can verify the integrity of the transaction order without accessing all transaction data. Each bundled transaction follows a specific format, comprising the source and destination chain IDs, the transaction payload, a timestamp, and a unique nonce to prevent replay attacks.

Once the order is committed, the Omni Sequencer distributes the bundled transactions to the respective rollups for block creation. Each rollup verifies the transaction order against the commit- ment on the DA layer and uses the Prover network to validate state transitions. The Prover Network generates zero-knowledge (zk) proofs to confirm state correctness and prevent fraudulent updates. The rollup then updates the state of its respective chain and sends the updated state along with the zk proof to the L1 chain for final inclusion in its block. For non-contract-based chains, the proof will be sent to a client for verification. This architecture ensures scalability by efficiently bundling and ordering transactions,security through zk proofs and commitments,and interoperability by supporting both contract-enabled and other chains. The flexible executor configurations enable adaptation to diverse performance and isolation needs, making the Omni Rollup a critical component of the Omnichain web for seamless cross-chain transaction processing.