Block Production

This section details Citrea's block production and finalization process, from transaction submission to confirmation. It covers the roles of the sequencer, commitments, mempool, and overall process.

Components Overview

You can read more on each component of the block production process with detailed explanation below:

• Mempool: A holding area for user transactions before they are included in a block.

• Sequencer: A special full node that orders the transactions, produces rollup blocks, and publishes commitments to the Bitcoin DA.

• Sequencer Commitments: Cryptographic commitments to the Citrea blocks that are inscribed on Bitcoin by the sequencer to prevent reorgs.

• Soft Confirmations: A confirmation mechanism used by the sequencer to provide soft-finality of blocks.

Block Production Process

Here is a diagram that shows process & components of block production in Citrea. Feel free to check each component above for more detailed information in the diagram.

Extended Block Production

In short, block production in Citrea is as follows:

• User transactions enter the mempool where they undergo some checks until they are included in a block.

• The sequencer selects valid transactions from the mempool, orders them, and produces a rollup block.

• The sequencer also provides soft confirmations alongside the block data, allowing full nodes to update their local chain state with a soft-finality.

• For full nodes to finalize the ordering of the transactions, sequencer commitments are inscribed on Bitcoin by the sequencer, allowing them to trustlessly verify the blocks.

• Lastly, the proving of execution is completed by the prover and batch proofs are inscribed (and finalized) on Bitcoin, and hence block becomes finalized & proven.