> ## 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.

# Deployment Pipeline

> Learn about the stages of the OP Deployer deployment pipeline.

OP Deployer is architected as a pipeline where each stage is responsible for a single piece of the deployment process.
The pipeline consumes a configuration called an *intent* which describes the desired state of the chain, and
produces a file called the *state* which describes the current state of the chain during and after the deployment.
The steps of the pipeline are:

1. Initialization
2. Shared Contracts Deployment
3. Implementations Deployment
4. OP Chain Deployment
5. Alt-DA Deployment
6. Dispute Game Deployment
7. L2 Genesis Generation
8. Setting Start Block

State is written to disk after each state. This allows the pipeline to be restarted from any point in the event of a
recoverable error.

We'll cover each of these stages in more detail below.

## Initialization

During this step, OP Deployer sets initial values for the pipeline based on the user's intent. These values will be
used by downstream stages. For example, if the user is deploying using an existing set of shared contracts,
those contracts will be inserted into the state during this step.

## Shared Contracts/Implementations Deployment

Next, the base contracts for the chain are deployed. This includes shared management contracts like
`SuperchainConfig`, as well as implementation contracts that will be used for the OP Chain
deployment in the future like the OP Contracts Manager (OPCM).

Most chains will be configured to use existing implementations. In this case, these steps will be skipped.

## OP Chain Deployment

The OP Chain itself is deployed during this step. Multiple chains will be deployed if they are specified in the
intent. The deployment works by calling into the OPCM, which will emit an event for each successfully-deployed chain.

## Customizations Deployment

The next two steps (Alt-DA and Dispute Game) deploy customizations. As their names imply, they deploy Alt-DA and
additional dispute game contracts. Typically, these steps will be skipped as they are mostly useful in testing.

## L2 Genesis Generation

This step generates the L2 Genesis file which is used to initialize the chain. This file is generated by calling
into `L2Genesis.sol`, and dumping the outputted state.

## Setting Start Block

Lastly, the start block is set to the current block number on L1. This is done last to ensure that the start block
is relatively recent, since the deployment process can take arbitrarily long.