Rome Shared Sequencer

Explains the role of Rhea, Solana, Hercules, data availability layers, and settlement.

Rome rollup consists of the rollup's client such as OP Geth, Rhea as the shared sequencer, the rollup's smart contract on Solana, and Hercules.

1. Rhea takes rollup transactions, packages them as Rome (Solana) transactions, and submits them to Solana for sequencing.

2. Solana acts as the global state machine for all rollups as they reside on Solana as smart contracts. Rollup transactions are first executed on Solana, updating the rollup state on Solana. Solana decides the order of transactions.

3. Hercules accepts blocks from Solana and executes the block's payload on the rollup, thus advancing state of the rollup.

4. Data Availability is provided by posting data to Solana, Celestia, or Ethereum (based on the rollup configuration).

5. Settlement is done by committing state to Ethereum.