Decentralized shared sequencer and BFT-finalized data availability layer (HotShot consensus) used by rollups for fast pre-confirmations, cross-rollup atomicity, and credibly neutral ordering.
- 01shared sequencing across rollups
- 02fast pre-confirmations (sub-second)
- 03cross-rollup atomic composability
- 04OP Stack / Orbit / Polygon CDK / Cartesi rollups
- 05credibly neutral ordering
| Variable | Scope | Description |
|---|---|---|
| ESPRESSO_QUERY_URL | Client | Espresso query-service endpoint (e.g. https://query.decaf.testnet.espresso.network). |
| ESPRESSO_BUILDER_URL | Server | Espresso builder/submit endpoint for posting transactions to the shared sequencer. |
| ESPRESSO_NAMESPACE | Client | Numeric namespace (rollup ID) reserved for your rollup on the Espresso network. |
Use Espresso as the shared sequencer and DA layer for the rollup. Register a namespace, then route block production through Espresso so transactions get HotShot-finalized ordering and BFT pre-confirmations within ~1s. Configure the rollup's batcher/derivation pipeline (OP Stack, Orbit, CDK, etc.) to read its canonical chain from Espresso namespace blobs and to settle proofs/state to the chosen settlement layer. Use the query service for inclusion proofs and the builder API for transaction submission; verify finality with HotShot QCs before exposing soft-confirmed UX.
- ⚑Shared sequencing trades sovereign ordering control for cross-rollup atomicity — your rollup inherits Espresso's liveness and censorship-resistance assumptions.
- ⚑HotShot finality is BFT (~1s) but bridging that finality to Ethereum still requires the underlying stack's settlement window (e.g. 7-day OP challenge period) unless you add a fast-finality AVS.
- ⚑Namespace IDs are global and must be reserved — collisions silently mix data with another rollup.
- ⚑Espresso fees are paid in ETH on the settlement chain plus protocol fees — keep batcher hot wallets funded and model fees alongside your DA layer.
- ⚑Espresso can serve as DA itself or be paired with Celestia/EigenDA/Avail; mixing DA + shared sequencing roles changes your trust model and inclusion latency.
- ⚑Forks of the Espresso chain follow HotShot rules, not your rollup's — design reorg handling around Espresso's finalized view, not best-effort tips.