Sequencer modes

The sequencer mode decides who orders your rollup's transactions before they are batched and anchored. The RDK supports three.

Mode	Who sequences	Notes
dedicated	A single operator	Simplest to run; you control ordering
shared	A distributed sequencer set	Spreads ordering across multiple parties
based	Host-chain proposers	Required by based settlement

dedicated

A single operator orders the rollup's transactions. This is the simplest mode to run and the default for optimistic, zk, and sovereign profiles. You hold sequencing authority and accept the operational responsibility that comes with it.

shared

Ordering is distributed across a sequencer set rather than a single operator, reducing reliance on any one party. Use it when you want to decentralize sequencing while still settling optimistically, with zk proofs, or sovereignly.

based

Sequencing is delegated to host-chain proposers — the rollup does not run its own sequencer, and inclusion is inherited from the host chain. This is what gives based settlement its fast, host-coupled finality.

The based constraint

Based settlement and the based sequencer are linked:

based settlement requires the based sequencer mode. A configuration that selects based settlement with a dedicated or shared sequencer is rejected by validation.

import { presets } from "@qorechain/rdk";

// The gaming and enterprise presets already pair based settlement with the
// based sequencer.
const config = presets.gaming({ rollupId: "my-game" });
config.validate(); // ok

// Overriding the sequencer away from "based" while keeping based settlement
// fails validation.
const broken = presets.gaming({ rollupId: "my-game" }).set({ sequencer: "dedicated" });
const result = broken.validationResult();
console.log(result.valid); // false

Conversely, the based sequencer mode is intended for based settlement; pair them together. See Settlement paradigms for the full picture.