Introduction

Note: These docs are a work in progress and are actively being updated.

In the following documentation we generically refer to rollups and L2s, but Espresso supports any kind of application that requires transaction ordering and/or data availability.

The following section describes the high level components that make up Espresso:

• Espresso's sequencing marketplace: Layer 2 rollups sell their sequencing rights in a combinatorial lottery run as part of Espresso's sequencing marketplace. (A simple version of the marketplace is planned for Q2 2024. The full combinatorial lottery is planned for a later release.)

  • The layer 1 proposer on Ethereum has a right of first refusal (ROFR) for sequencing rights sold via the combinatorial lottery, allowing L2s to function as based rollups. (ROFR will be integrated following the release of the combinatorial lottery as part of the sequencing marketplace.)

• The HotShot shared finality layer: HotShot is Espresso's consensus protocol and shared finality layer. The results of the combinatorial lottery, as well as L2 transactions, are all finalized by HotShot in a matter of seconds.

  • Tiramisu DA layer: Nodes participating in HotShot consensus also make up Tiramisu, Espresso's data availability layer.

This documentation will explore these components in more detail, as well as how applications integrate with Espresso. The internal workings of tangential components, like specific L2s or the lower level detailsHotShot consensus protocol itself, are beyond the scope of this documentation.