---
title: Sequencer
description: Page on Vedang Vatsa's site: https://veda.ng/glossary/sequencer
canonical: https://veda.ng/glossary/sequencer
last_updated: 2026-10-03
type: text/markdown
---
# Sequencer

Source: https://veda.ng/glossary/sequencer
Author: Vedang Vatsa (https://veda.ng/about)

A sequencer orders and batches rollup transactions before posting them to Layer 1. It decides inclusion, order, and timing. Most rollups still use a centralized sequencer run by the team. Offchain Labs runs Arbitrum's. The Optimism Foundation runs Optimism's. That creates censorship risk, MEV extraction by reordering, and liveness risk if the sequencer dies. Escape hatches let users force-include via L1, slowly and expensively.

Decentralizing sequencers is a roadmap item. Ideas include rotating sets, leader election among staked operators, and shared sequencers across rollups. Shared sequencing could enable atomic cross-rollup trades and cut fragmentation. Sequencers earn fees and MEV, which is a valuable right. How that revenue is split among token holders, stakers, or public goods shapes rollup economics. Sequencer decentralization is still an open design problem. This centralization creates several concerns: censorship risk (the sequencer could refuse to include certain transactions), MEV extraction (the sequencer can reorder transactions to extract value), and liveness risk (if the sequencer goes down, the rollup halts). Sequencer decentralization is a major priority for rollup roadmaps. The sequencer revenue model matters too: sequencers earn fees and MEV, creating valuable property rights. Most rollups still use one sequencer to order transactions. That is fast. It is also a censorship and downtime point until sequencing is shared.

Glossary index: https://veda.ng/glossary