> ## Documentation Index
> Fetch the complete documentation index at: https://docs.optimism.io/llms.txt
> Use this file to discover all available pages before exploring further.

# op-node

> Canonical hub for op-node, the OP Stack rollup node in Go, covering what it does, who runs it, and where its guides, reference, releases, source, and spec live.

op-node is the OP Stack's consensus-layer client, written in Go: the rollup
node that derives the canonical L2 chain from L1 data and drives an execution
client to process the resulting blocks.

## Overview

op-node builds, relays, and verifies the canonical chain of L2 blocks. As a
sequencer it builds new blocks; as a verifier it derives blocks from the data
the chain posted to L1 and accepts only blocks that can be reproduced from
that data. The blocks themselves are executed by an execution client, such as
op-reth, which op-node controls through the Engine API; the two run in a
one-to-one pairing. op-node also relays the sequencer's new (unsafe) blocks
over a P2P network for low-latency access to the latest state; the relay is
optional and never affects the ability to verify.

It exists because an OP Stack chain is *derived*: the canonical chain is
defined by data available on L1, and the rollup node is the component that
turns that data into verified L2 blocks. It plays the role a beacon node
plays on L1, and it implements the rollup node specification.

**Who runs it:** every node operator. Each OP Stack node pairs a rollup node,
op-node or [kona-node](/releases/kona-node) (the Rust implementation of the
same role), with an execution client. Chain operators additionally run
op-node in sequencer mode to build new blocks.

## Get started

* [Running a Node With Docker](/node-operators/tutorials/node-from-docker):
  run op-node and op-reth from the official Docker images. To build and run
  from source instead, see
  [Building and running an OP Stack node from source](/node-operators/tutorials/run-node-from-source).

## How-tos

* [Consensus client configuration](/node-operators/guides/configuration/consensus-clients):
  configure op-node (or kona-node) and connect it to your execution client.
* [Using blobs](/node-operators/guides/management/blobs): give op-node the
  L1 beacon endpoint it needs to fetch blob batch data, including blobs
  older than the beacon retention window.
* [Node troubleshooting](/node-operators/guides/troubleshooting): solutions
  to common node problems, many of them surfaced in op-node logs.

## Configuration & flags reference

* [op-node configuration options](/node-operators/reference/op-node-config):
  every CLI flag and environment variable, with flag tables generated from
  the op-node release named on the page.
* [op-node JSON-RPC API](/node-operators/reference/op-node-json-rpc): the
  rollup-specific RPC methods op-node serves.

## Releases

* [op-node release history](/releases/op-node)

## Source & spec links

* [Source: `op-node/`](https://github.com/ethereum-optimism/optimism/tree/develop/op-node)
  in the Optimism monorepo; its
  [README](https://github.com/ethereum-optimism/optimism/blob/develop/op-node/README.md)
  documents the quickstart, design principles, and failure modes (L1
  downtime, L1 reorgs, sequencer window expiry, and more).
* [Rollup node specification](https://specs.optimism.io/protocol/rollup-node.html):
  the normative definition of the rollup node's role.
* [L2 chain derivation specification](https://specs.optimism.io/protocol/derivation.html):
  the normative definition of how the canonical L2 chain is derived from L1
  data.