> ## 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.

# Stack Components

> One canonical hub page per OP Stack component, grouped by protocol role.

This section gives every OP Stack component exactly one identity page — its
**hub** — so "where do I find docs for component X" always has the same
answer. Each hub follows the same
[skeleton](/op-stack/contribute/component-hub-template): what the component
is, who runs it, where to start, and where its guides, configuration
reference, releases, source, and spec live.

Components are grouped by their role in the protocol. For how these roles fit
together conceptually — data availability, sequencing, derivation, execution,
settlement — see the [OP Stack components](/op-stack/protocol/components)
explanation. For release history across all components, see
[Releases](/releases).

Hubs are shipping in reviewed batches. Components without a hub yet are
listed with their release history; their hub pages follow.

## Sequencing

Producing L2 blocks and making their data available.

| Component    | What it does                                                | Hub                                    | Releases                           |
| ------------ | ----------------------------------------------------------- | -------------------------------------- | ---------------------------------- |
| op-batcher   | Posts L2 transaction batches to the data availability layer | [Hub](/op-stack/components/op-batcher) | [Releases](/releases/op-batcher)   |
| op-conductor | High-availability sequencer coordination service            | Planned                                | [Releases](/releases/op-conductor) |

## Derivation & execution

Deriving the canonical L2 chain from the data availability layer and
executing its blocks.

| Component | What it does                                         | Hub     | Releases                        |
| --------- | ---------------------------------------------------- | ------- | ------------------------------- |
| op-node   | OP Stack consensus-layer (rollup node) client, in Go | Planned | [Releases](/releases/op-node)   |
| kona-node | Rust implementation of the OP Stack rollup node      | Planned | [Releases](/releases/kona-node) |
| op-reth   | OP Stack execution-layer client built on Reth        | Planned | [Releases](/releases/op-reth)   |

## Settlement & proofs

Proposing L2 state to L1 and proving its validity.

| Component     | What it does                                                             | Hub                                | Releases                                                                                            |
| ------------- | ------------------------------------------------------------------------ | ---------------------------------- | --------------------------------------------------------------------------------------------------- |
| op-proposer   | Proposes L2 output roots to L1                                           | Planned                            | [Releases](/releases/op-proposer)                                                                   |
| op-challenger | Dispute game challenge agent                                             | Planned                            | [Releases](/releases/op-challenger)                                                                 |
| cannon        | Onchain MIPS instruction emulator — the fault proof VM                   | [Hub](/op-stack/components/cannon) | [Release tags](https://github.com/ethereum-optimism/optimism/releases?q=cannon%2Fv\&expanded=false) |
| kona-client   | Fault proof program (client) that executes the OP Stack state transition | Planned                            | [Releases](/releases/kona-client)                                                                   |
| kona-host     | Fault proof host that serves preimage data to kona-client                | Planned                            | [Releases](/releases/kona-host)                                                                     |
| op-contracts  | OP Stack L1 and L2 smart contracts                                       | Planned                            | [Releases](/releases/op-contracts)                                                                  |

## Deployment & infrastructure

Deploying chains and operating the infrastructure around them.

| Component   | What it does                                   | Hub     | Releases                          |
| ----------- | ---------------------------------------------- | ------- | --------------------------------- |
| op-deployer | OP Stack chain deployment and upgrade tool     | Planned | [Releases](/releases/op-deployer) |
| proxyd      | RPC request router and proxy                   | Planned | [Releases](/releases/proxyd)      |
| op-acceptor | Network acceptance tester for OP Stack devnets | Planned | [Releases](/releases/op-acceptor) |