What is an Arbitrum Orbit chain?
Arbitrum Orbit is a framework that allows developers to launch their own Layer 2 chains using the Arbitrum Nitro codebase. Instead of building a new blockchain from scratch, you deploy a chain that shares security with the Ethereum mainnet. This setup lets you customize gas tokens, sequencer policies, and data availability to fit specific project needs without sacrificing the underlying security guarantees.
Think of Orbit as a modular toolkit rather than a single product. It is the strategic path for projects that need their own dedicated chain infrastructure while staying within the Arbitrum ecosystem. This contrasts with the shared-security "One" chain model, where all users share the same chain resources. Orbit gives you the independence to design a chain that aligns with your specific economic and technical requirements.
By leveraging the Nitro codebase, your Orbit chain benefits from the same high-performance execution environment that powers Arbitrum Nova and Arbitrum One. You get fast finality and low costs, but with the flexibility to tailor the chain’s governance and fee structures. This makes Orbit ideal for specialized applications, enterprise use cases, or community-driven projects that require full control over their chain’s parameters.
For more details on the Nitro stack and chain customization options, see the Arbitrum documentation on launching a chain. The Arbitrum DAO governance docs also outline the strategy for deploying new chains within the ecosystem.
Choose your Orbit chain type
Selecting the right Arbitrum Orbit configuration depends on your project's specific requirements for data availability, transaction throughput, and governance control. Arbitrum Nitro supports three primary chain types, each designed for different operational models. Understanding the trade-offs between these configurations helps you avoid over-engineering or under-securing your deployment.
The choice primarily revolves around how you handle data availability and who controls the sequencer. The Orbit Chain (standard) offers full customization, allowing you to choose your own Data Availability (DA) layer and sequencer setup. The Arbitrum Nova chain is optimized for high throughput and low fees by sharing data availability with the main Arbitrum chain, while the Arbitrum One chain is the base Layer-2 network itself, not a child chain you launch.
For most developers building a new application, you are choosing between a fully sovereign Orbit chain or leveraging the shared infrastructure of Nova. Below is a comparison of the key configuration variables.
| Configuration | Data Availability | Sequencer Control | Validator Set |
|---|---|---|---|
| Orbit Chain (Standard) | Custom (Ethereum, Celestia, EigenDA) | Self-hosted or Third-party | Custom or Shared |
| Arbitrum Nova | Arbitrum Foundation | Shared with Arbitrum One | |
| Arbitrum One | Arbitrum Foundation | Arbitrum One Committee |
Data Availability Layer
Your choice of Data Availability (DA) layer is the most critical technical decision. If you select an Orbit chain, you can host data on Ethereum L1, which offers the highest security but higher costs. Alternatively, you can use modular DA layers like Celestia or EigenDA to reduce costs significantly, though this introduces different trust assumptions. Nova chains do not make this choice; they inherit the DA layer from Arbitrum One, simplifying the setup but limiting customization.
Sequencer Setup
The sequencer orders transactions and prevents double-spending. In a standard Orbit chain, you can run your own sequencer for maximum control and censorship resistance, or use a third-party provider for ease of management. Nova and Arbitrum One rely on sequencers managed by the Arbitrum Foundation, which centralizes control but ensures consistency with the broader network.
Validator Requirements
Validators secure the chain by verifying state transitions. Orbit chains allow you to define your own validator set, which can be permissioned (for enterprise use) or permissionless (for public networks). Nova and Arbitrum One use a shared validator set, meaning you benefit from the security of the larger Arbitrum network without needing to recruit your own validators.
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Define your data availability budget and security needs.
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Decide if you need full sequencer control or shared infrastructure.
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Determine if your validator set should be permissioned or permissionless.
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Select the Orbit chain type that matches your governance model.
For more detailed technical specifications on configuring these chains, refer to the Arbitrum Nitro documentation.
Set up the development environment
Before configuring an Arbitrum Orbit chain, you need a local environment that mirrors the Nitro node architecture. This section walks you through installing the required dependencies, cloning the official SDK, and initializing the node configuration.
Nitro nodes require Node.js (LTS version recommended) and Go. Use your system package manager or the official Node.js installer. Ensure git is installed for cloning repositories. Verify installations by running node -v and go version in your terminal.
Navigate to your development directory and clone the official SDK repository. This repository contains the core codebase for building Arbitrum chains. Run the following command to fetch the latest stable version:
git clone https://github.com/OffchainLabs/arbitrum-chain-sdk.git
cd arbitrum-chain-sdk
Install the project dependencies using your preferred package manager (e.g., npm install or yarn install).
The SDK provides a CLI tool to scaffold your chain configuration. Run the initialization command to generate the necessary configuration files and directory structure. This step sets up the default Nitro node parameters, which you will customize in the next phase. Review the generated files to understand the default architecture before proceeding.
With the environment ready, you can begin customizing the chain parameters. The default configuration provides a functional baseline, but most production chains require adjustments to gas limits, sequencer settings, and settlement layers.
Configure chain parameters and DA layer
Setting up your Arbitrum Orbit chain requires defining the core mechanics of how blocks are produced and where data is stored. These decisions determine your chain's throughput, finality speed, and long-term security model.
Adjust the block time to match your application's latency requirements. Standard Arbitrum chains often use 250ms or 500ms block times, but you can increase this for higher throughput or decrease it for faster user feedback. Set the gas limit to cap the computational resources allowed per block, preventing network congestion and ensuring predictable transaction costs for users.
Your chain needs a secure place to store transaction data. You can choose Ethereum L1 for maximum security and decentralization, though this incurs higher data fees. Alternatively, use Celestia or EigenDA for lower costs and higher throughput, accepting a different security trade-off. This choice directly impacts your gas token economics and settlement trust assumptions.
Choose whether your chain uses ETH or a custom token for gas payments. This decision affects user onboarding complexity and your ability to subsidize fees. Configure the fee market parameters to ensure validators are compensated fairly while keeping costs stable for end-users.
Specify the addresses and keys for your sequencer and data availability providers. The sequencer orders transactions before they are posted to the DA layer. Ensure you have redundancy in place to maintain chain liveness if the primary sequencer goes offline.
Review the Arbitrum Nitro configuration documentation to ensure all parameters are correctly aligned with your chain's specific use case before deployment.
Deploy the chain to mainnet
With your configuration finalized, the final phase involves deploying the RollupCreator smart contract to Ethereum mainnet and initializing your sequencer node. This process mints the rollup contract and establishes the on-chain settlement layer for your Arbitrum Orbit chain.
Deploy the RollupCreator contract to Ethereum mainnet using your preferred web3 provider. This contract acts as the factory for your new chain. You will pass your rollup_config.json parameters to the createRollup function. This transaction locks in your chain’s genesis state and assigns the initial owner address. The transaction will incur standard Ethereum gas fees, which vary based on network congestion.
Once the RollupCreator transaction is confirmed, extract the new rollup contract address from the transaction receipt. Use this address to configure your sequencer node. Start the node pointing to your Ethereum mainnet RPC and your local database. The sequencer will begin syncing the latest block from the L1 contract and start producing blocks for your new Orbit chain. Monitor the logs to ensure it successfully connects to the settlement layer.
Confirm your chain is live by checking the block height on your sequencer. You can also verify the rollup contract on Etherscan using the address from the RollupCreator deployment. Finally, deploy your core application contracts to the new L2 chain using your standard deployment tools. Ensure your frontend and backend services are updated to point to the new L2 RPC endpoint for user traffic.
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