OP Stack Configurability

Table of Contents

Consensus Parameters
- Resource Config
Policy Parameters
Admin Roles
Service Roles

When deploying the OP Stack software to a production environment, certain parameters about the protocol can be configured. These configurations can include a variety of parameters which affect the resulting properties of the blockspace in question.

There are four categories of OP Stack configuration options:

Consensus Parameters: Parameters and properties of the chain that may be set at genesis and fixed for the lifetime of the chain, or may be changeable through a privileged account or protocol upgrade.
Policy Parameters: Parameters of the chain that might be changed without breaking consensus. Consensus is enforced by the protocol, while policy parameters may be changeable within constraints imposed by consensus.
Admin Roles: These roles can upgrade contracts, change role owners, or update protocol parameters. These are typically cold/multisig wallets not used directly in day to day operations.
Service Roles: These roles are used to manage the day-to-day operations of the chain, and therefore are often hot wallets.

Each category also defines the standard configuration values for it's given parameters. Standard configuration is the set of requirements for an OP Stack chain to be considered a Standard Chain within the superchain. These requirements are currently a draft, pending governance approval.

The recommended way to deploy L1 contracts for an OP chain that meet the standard configuration will be with the OP Stack Manager.

Consensus Parameters

Config Property	Description	Administrator	Standard Config Requirement	Notes
Batch Inbox address	L1 address where calldata/blobs are posted (see Batcher Transaction).	Static	Current convention is `versionByte \|\| keccak256(bytes32(chainId))[:19]`, where `\|\|` denotes concatenation, `versionByte` is `0x00`, and `chainId` is a `uint256`.	It is recommended, but not required, to follow this convention.
Batcher Hash	A versioned hash of the current authorized batcher sender(s).	System Config Owner	`bytes32(uint256(uint160(batchSubmitterAddress)))`	Batch Submitter address padded with zeros to fit 32 bytes.
Chain ID	Unique ID of Chain used for TX signature validation.	Static	Foundation-approved, globally unique value ¹.	Foundation will ensure chains are responsible with their chain IDs until there's a governance process in place.
Proof Maturity Delay	The length of time that must pass between proving and finalizing a withdrawal.	L1 Proxy Admin	7 days	High security. Excessively safe upper bound that leaves enough time to consider social layer solutions to a hack if necessary. Allows enough time for other network participants to challenge the integrity of the corresponding output root.
Dispute Game Finality	The amount of time given to the `Guardian` role to blacklist a resolved dispute game before any withdrawals proven against it can be finalized, in the case of a system failure.	L1 Proxy Admin	3.5 days	High security. Allows enough time for the `Guardian` to blacklist games.
Respected Game Type	The respected game type of the `OptimismPortal`. Determines the type of dispute games that can be used to finalize withdrawals.	Guardian	`CANNON` (`0`)	The game type may be changed to `PERMISSIONED_CANNON` (`1`) as a fallback to permissioned proposals, in the event of a failure in the Fault Proof system.
Fee Scalar	Markup on transactions compared to the raw L1 data cost.	System Config Owner	Set such that Fee Margin is between 0 and 50%.
Gas Limit	Gas limit of the L2 blocks is configured through the system config.	System Config Owner	No higher than 200_000_000 gas	Chain operators are driven to maintain a stable and reliable chain. When considering to change this value, careful deliberation is necessary.
Genesis state	Initial state at chain genesis, including code and storage of predeploys (all L2 smart contracts). See Predeploy.	Static	Only standard predeploys and preinstalls, no additional state.	Homogeneity & standardization, ensures initial state is secure.
L2 block time	Frequency with which blocks are produced as a result of derivation.	L1 Proxy Admin	2 seconds	High security & interoperability compatibility requirement, until de-risked/solved at app layer.
Resource config	Config for the EIP-1559 based curve used for the deposit gas market.	L1 Proxy Admin	See resource config table.	Constraints are imposed in code when setting the resource config.
Sequencing window Size	Maximum allowed batch submission gap, after which L1 fallback is triggered in derivation.	Static	3_600 base layer blocks (12 hours for an L2 on Ethereum, assuming 12 second L1 blocktime). e.g. 12 second blocks, $3600 * 12 seco n d s \div 60 \frac{seco n d s}{min u t e} \div 60 \frac{min u t e}{h o u r} = 12 h o u rs$ .	This is an important value for constraining the sequencer's ability to re-order transactions; higher values would pose a risk to user protections.
Start block	Block at which the system config was initialized the first time.	L1 Proxy Admin	The block where the SystemConfig was initialized.	Simple clear restriction.
Superchain target	Choice of cross-L2 configuration. May be omitted in isolated OP Stack deployments. Includes SuperchainConfig and ProtocolVersions contract addresses.	Static	Mainnet or Sepolia	A superchain target defines a set of layer 2 chains which share `SuperchainConfig` and `ProtocolVersions` contracts deployed on layer 1.
Governance Token	OP token used for the Optimism Collective's Token House governance.	n/a	Disabled	Simple clear restriction.

The chain ID must be globally unique among all EVM chains.

Resource Config

Config Property	Standard Config Requirement
maxResourceLimit	$2 * 1 0^{7}$
elasticityMultiplier	$10$
baseFeeMaxChangeDenominator	$8$
minimumBaseFee	$1 * 1 0^{9}$
systemTxMaxGas	$1 * 1 0^{6}$
maximumBaseFee	$2^{128}$ -1

Policy Parameters

Config Property	Description	Administrator	Standard Config Requirement	Notes
Data Availability Type	Batcher can currently be configured to use blobs or calldata (See Data Availability Provider).	Batch submitter address	Ethereum (Blobs, Calldata)	Alt-DA is not yet supported for the standard configuration, but the sequencer can switch at-will between blob and calldata with no restriction, since both are L1 security.
Batch submission frequency	Frequency with which batches are submitted to L1 (see Batcher Transaction).	Batch submitter address	1_800 base layer blocks (6 hours for an L2 on Ethereum, assuming 12 second L1 blocktime) or lower	Batcher needs to fully submit each batch within the sequencing window, so this leaves buffer to account for L1 network congestion and the amount of data the batcher would need to post.
Output frequency	Frequency with which output roots are submitted to L1.	L1 Proxy Admin	43_200 L2 Blocks (24 hours for an L2 on Ethereum, assuming 2 second L2 blocktime) or lower e.g. 2 second blocks, $43200 * 2 seco n d s \div 60 \frac{seco n d s}{min u t e} \div 60 \frac{min u t e}{h o u r} = 24 h o u rs$ .	Deprecated once fault proofs are implemented. This value cannot be 0.

Admin Roles

Config Property	Description	Administrator	Administers	Standard Config Requirement	Notes
L1 Proxy Admin	Account authorized to upgrade L1 contracts.	L1 Proxy Admin Owner	Batch Inbox Address, Start block, Proposer address, Challenger address, Guardian address, Proof Maturity Delay, Dispute Game Finality, Output frequency, L2 block time, L1 smart contracts	ProxyAdmin.sol from the latest `op-contracts/vX.Y.X` release of source code in Optimism repository.	Governance-controlled, high security.
L1 ProxyAdmin owner	Account authorized to update the L1 Proxy Admin.		L1 Proxy Admin	0x5a0Aae59D09fccBdDb6C6CcEB07B7279367C3d2A ²	Governance-controlled, high security.
L2 Proxy Admin	Account authorized to upgrade L2 contracts.	L2 Proxy Admin Owner	Predeploys	ProxyAdmin.sol from the latest `op-contracts/vX.Y.X` release of source code in Optimism repository. Predeploy address: 0x4200000000000000000000000000000000000018.	Governance-controlled, high security.
L2 ProxyAdmin owner	Account authorized to upgrade protocol contracts via calls to the `ProxyAdmin`. This is the aliased L1 ProxyAdmin owner address.		L2 Proxy Admin	Gnosis Safe between Optimism Foundation (OF) and the Security Council (SC). Aliased Address: 0x6B1BAE59D09fCcbdDB6C6cceb07B7279367C4E3b ³	Governance-controlled, high security.
System Config Owner	Account authorized to change values in the SystemConfig contract. All configuration is stored on L1 and picked up by L2 as part of the derivation of the L2 chain.		Batch submitter address, Sequencer P2P / Unsafe head signer, Fee Margin, Gas limit, System Config Owner	Chain Governor or Servicer	As defined in the Law of Chains

2 of 2 GnosisSafe between Optimism Foundation (OF) and the Security Council (SC) on L1. Mainnet and Sepolia addresses can be found at privileged roles.

Aliased address of the 2 of 2 Gnosis Safe between Optimism Foundation (OF) and the Security Council (SC) on L1. The reason for aliasing can be found in the glossary. This address was calculated using the following arithmetic: 0x5a0Aae59D09fccBdDb6C6CcEB07B7279367C3d2A + 0x1111000000000000000000000000000000001111 = 0x6B1BAE59D09fCcbdDB6C6cceb07B7279367C4E3b.

Service Roles

Config Property	Description	Administrator	Standard Config Requirement	Notes
Batch submitter address	Account which authenticates new batches submitted to L1 Ethereum.	System Config Owner	No requirement
Challenger address	Account which can interact with existing permissioned dispute games.	L1 Proxy Admin	0x9BA6e03D8B90dE867373Db8cF1A58d2F7F006b3A ⁴	Optimism Foundation (OF) multisig leveraging battle-tested software. This role is only active when the `OptimismPortal` respected game type is `PERMISSIONED_CANNON`.
Guardian address	Account authorized to pause L1 withdrawals from contracts, blacklist dispute games, and set the respected game type in the `OptimismPortal`.	L1 Proxy Admin	0x09f7150D8c019BeF34450d6920f6B3608ceFdAf2	A 1/1 Safe owned by the Security Council Safe, with the Deputy Guardian Module enabled to allow the Optimism Foundation to act as Guardian.
Proposer address	Account which can create and interact with permissioned dispute games on L1.	L1 Proxy Admin	No requirement	This role is only active when the `OptimismPortal` respected game type is `PERMISSIONED_CANNON`. The `L1ProxyAdmin` sets the implementation of the `PERMISSIONED_CANNON` game type. Thus, it determines the proposer configuration of the permissioned dispute game.
Sequencer P2P / Unsafe head signer	Account which authenticates the unsafe/pre-submitted blocks for a chain at the P2P layer.	System Config Owner	No requirement

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5 of 7 GnosisSafe controlled by Optimism Foundation (OF). Mainnet and Sepolia addresses can be found at privileged roles.