> ## 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-contracts

> Canonical hub for op-contracts, the OP Stack L1 and L2 smart contracts, covering what they do, how they are deployed and upgraded, and where their reference, releases, source, and specs live.

op-contracts is the OP Stack's smart contract layer: the L1 contracts that
anchor an OP Stack chain to Ethereum and the L2 predeploy contracts that
every OP Stack chain ships in its genesis state. Both live in
`packages/contracts-bedrock` in the Optimism monorepo and release together as
`op-contracts/vX.Y.Z`.

## Overview

The L1 contracts, deployed on Ethereum, facilitate cross-domain message
passing and maintain the valid state root of the L2: deposits enter the chain
through them, withdrawals are proven and finalized against dispute game
results, and the chain's onchain configuration lives in them. The L2
predeploys sit at predetermined addresses in the genesis state and provide
the chain's built-in functionality, from the cross-domain messengers and
bridges to the fee vaults and the gas price oracle. For a
contract-by-contract tour of both layers, see the
[smart contract overview](/op-stack/protocol/smart-contracts).

It exists because an OP Stack chain's security anchors on Ethereum: the
bridge, the state proposals that dispute games check, and the withdrawal path
that [op-challenger](/op-stack/components/op-challenger) defends are all
enforced by these contracts.

**Who runs it:** nobody operates op-contracts as a service; the contracts run
onchain. Chain operators deploy a chain's L1 contracts with
[op-deployer](/op-stack/components/op-deployer) and upgrade them through the
[OP Contracts Manager](/chain-operators/reference/opcm), which deploys and
upgrades the contracts for a chain in a single transaction.

## Get started

* [Deploy L1 contracts with op-deployer](/chain-operators/tutorials/create-l2-rollup/op-deployer-setup):
  install op-deployer, prepare your environment, and deploy the L1
  contracts for a new OP Stack chain.

## How-tos

* [Upgrade using superchain-ops](/chain-operators/tutorials/l1-contract-upgrades/superchain-ops-guide):
  upgrade a chain's L1 contracts with the superchain-ops task workflow,
  the path for chains that require security council signing or a more
  secure upgrade process.
* [Upgrade L1 contracts using op-deployer](/chain-operators/tutorials/l1-contract-upgrades/op-deployer-upgrade):
  version availability and migration paths for op-deployer's deprecated
  `upgrade` command, which supports upgrades only up to
  `op-contracts/v5.0.0`.

## Configuration & flags reference

op-contracts has no CLI; its configuration surface is the deployment
configuration the contracts are deployed with.

* [Rollup deployment configuration](/chain-operators/reference/rollup-deployment-configuration):
  every deploy config field, generated from source and keyed to the
  finalized op-deployer release named on the page.
* [What makes a chain standard?](/chain-operators/reference/standard-configuration):
  the standard configuration values a chain must adhere to.

## Releases

* [op-contracts release history](/releases/op-contracts). Production
  contract releases are always tagged `op-contracts/vX.Y.Z`; releases
  tagged `v<semver>` without a component name contain no smart contracts.
* [Smart contract versioning policy](https://github.com/ethereum-optimism/optimism/blob/develop/packages/contracts-bedrock/book/src/policies/versioning.md):
  the in-repo definition of the release process.

## Source & spec links

* [Source: `packages/contracts-bedrock/`](https://github.com/ethereum-optimism/optimism/tree/develop/packages/contracts-bedrock)
  in the Optimism monorepo.
* [Contracts book](https://devdocs.optimism.io/contracts-bedrock):
  the in-repo developer book, covering interface documentation,
  architecture, and contract policies.
* [Deposits specification](https://specs.optimism.io/protocol/deposits.html):
  the normative definition of the deposit path the L1 contracts implement.
* [Withdrawals specification](https://specs.optimism.io/protocol/withdrawals.html):
  the normative definition of the withdrawal path.
* [Predeploys specification](https://specs.optimism.io/protocol/predeploys.html):
  the normative definition of the L2 predeploy contracts.