Configuration

Reference for Base Chain configuration parameters across consensus, policy, admin, and sequencer categories.

There are four categories of Base configuration:

• Consensus Parameters: Fixed at genesis or changeable through privileged accounts or protocol upgrades.
• Policy Parameters: Changeable without breaking consensus, within protocol-imposed constraints.
• Admin Roles: Accounts that can upgrade contracts, change role owners, or update protocol parameters. Typically cold/multisig wallets.
• Service Roles: Accounts used for day-to-day operations. Typically hot wallets.

Consensus Parameters

Parameter	Description	Administrator
Batch Inbox Address	L1 address where batcher transactions are posted	Static
Batcher Hash	Versioned hash of the authorized batcher sender(s)	System Config Owner
Chain ID	Unique chain ID for transaction signature validation	Static
Proof Maturity Delay	Time between proving and finalizing a withdrawal. 7 days.	L1 Proxy Admin
Dispute Game Finality	Time for Guardian to blacklist a game before withdrawals finalize. 3.5 days.	L1 Proxy Admin
Respected Game Type	Game type OptimismPortal accepts for withdrawal finalization. CANNON (0); may fall back to PERMISSIONED_CANNON (1).	Guardian
Fault Game Max Depth	Maximum depth of fault dispute game trees. 73.	Static
Fault Game Split Depth	Depth after which claims correspond to VM state commitments. 30.	Static
Max Game Clock Duration	Maximum time on a dispute game team’s chess clock. 3.5 days.	Static
Game Clock Extension	Clock credit when a team’s remaining time falls below CLOCK_EXTENSION. 3 hours.	Static
Bond Withdrawal Delay	Time before dispute game bonds can be withdrawn. 7 days.	Static
Min Large Preimage Size	Minimum preimage size for the PreimageOracle large proposal process. 126,000 bytes.	Static
Large Preimage Challenge Period	Challenge window before large preimage proposals are published. 24 hours.	Static
Fault Game Absolute Prestate	VM state commitment used as the fault proof VM starting point	Static
Fault Game Genesis Block	Initial anchor state block number. Any finalized block between bedrock and fault proof activation; 0 from genesis.	Static
Fault Game Genesis Output Root	Output root at the Fault Game Genesis Block	Static
Fee Scalar	Markup on transactions relative to raw L1 data cost. Fee margin between 0%–50%.	System Config Owner
Gas Limit	L2 block gas limit. ≤ 200,000,000 gas.	System Config Owner
Genesis State	Initial chain state including all predeploy code and storage. Standard predeploys and preinstalls only.	Static
L2 Block Time	Interval at which L2 blocks are produced via derivation. 1 or 2 seconds.	L1 Proxy Admin
Sequencing Window Size	Max batch submission gap before L1 fallback triggers. 3,600 L1 blocks (12 hours at 12s L1 block time).	Static
Start Block	L1 block where SystemConfig was first initialized	L1 Proxy Admin
Superchain Target	SuperchainConfig and ProtocolVersions addresses for cross-L2 config. Mainnet or Sepolia.	Static
Governance Token	OP governance token. Disabled.	n/a
Operator Fee Params	Operator fee scalar and constant for fee calculation. Standard values are 0; non-zero for non-standard configurations such as op-succinct.	System Config Owner
DA Footprint Gas Scalar	Scalar for DA footprint calculation	System Config Owner
Minimum Base Fee	Minimum base fee on L2	System Config Owner

Policy Parameters

Parameter	Description	Administrator
Data Availability Type	Whether the batcher posts data as blobs or calldata. Ethereum (Blobs or Calldata); Alt-DA not supported.	Batch Submitter
Batch Submission Frequency	Frequency of batcher transaction submissions to L1. ≤ 1,800 L1 blocks (6 hours at 12s L1 block time).	Batch Submitter
Output Frequency	Frequency of output root submissions to L1. ≤ 43,200 L2 blocks (24 hours at 2s L2 block time); must be non-zero. Deprecated once fault proofs are enabled.	L1 Proxy Admin

Admin Roles

Role	Description	Administers
L1 Proxy Admin	ProxyAdmin from the latest op-contracts release, authorized to upgrade L1 contracts	L1 contracts
L1 ProxyAdmin Owner	Authorized to update the L1 Proxy Admin. 0x5a0Aae59D09fccBdDb6C6CcEB07B7279367C3d2A	L1 Proxy Admin
L2 Proxy Admin	ProxyAdmin at 0x4200000000000000000000000000000000000018, authorized to upgrade L2 contracts	Predeploys
L2 ProxyAdmin Owner	Aliased L1 ProxyAdmin Owner; upgrades L2 contracts via ProxyAdmin. 0x6B1BAE59D09fCcbdDB6C6cceb07B7279367C4E3b	L2 Proxy Admin
System Config Owner	Authorized to change values in the SystemConfig contract	Batch Submitter, Sequencer P2P Signer, Fee Scalar, Gas Limit

Service Roles

Role	Description	Administrator
Batch Submitter	Authenticates batches submitted to L1	System Config Owner
Challenger	Interacts with permissioned dispute games. Active only when respected game type is PERMISSIONED_CANNON. 0x9BA6e03D8B90dE867373Db8cF1A58d2F7F006b3A	L1 Proxy Admin
Guardian	Pauses L1 withdrawals, blacklists dispute games, sets respected game type in OptimismPortal. 0x09f7150D8c019BeF34450d6920f6B3608ceFdAf2	L1 Proxy Admin
Proposer	Creates permissioned dispute games on L1. Active only when respected game type is PERMISSIONED_CANNON.	L1 Proxy Admin
Sequencer P2P Signer	Signs unsafe/pre-submitted blocks at the P2P layer	System Config Owner

Changelog

This section tracks configuration changes to the Base networks, including updates to block building, network fees, and other network parameters.

Base Mainnet

Date	Change	Documentation
February 19, 2026	Increased Minimum Base Fee to 5,000,000 wei	Minimum Base Fee
February 4, 2026	Increased EIP-1559 Denominator to 125	EIP-1559 Fee Parameters
February 2, 2026	Increased Minimum Base Fee to 2,000,000 wei	Minimum Base Fee
January 22, 2026	Increased Minimum Base Fee to 1,000,000 wei	Minimum Base Fee
December 18, 2025	Increased Minimum Base Fee to 500,000 wei	Minimum Base Fee
December 4, 2025	Enabled Minimum Base Fee (200,000 wei)	Minimum Base Fee
September 17, 2025	Enabled Per-Transaction Gas Maximum	Per-Transaction Gas Maximum
September 11, 2025	Ended testing Per-Transaction Gas Maximum	Per-Transaction Gas Maximum
September 10, 2025	Started testing Per-Transaction Gas Maximum	Per-Transaction Gas Maximum
July 7, 2025	Enabled Flashblocks	Flashblocks
May 15, 2025	Ended testing Flashblocks	Flashblocks
May 15, 2025	Started testing Flashblocks	Flashblocks

Base Sepolia

Date	Change	Documentation
February 19, 2026	Increased Minimum Base Fee to 5,000,000 wei	Minimum Base Fee
February 10, 2026	Increased EIP-1559 Denominator to 125	EIP-1559 Fee Parameters
February 10, 2026	Increased Minimum Base Fee to 2,000,000 wei	Minimum Base Fee
November 20, 2025	Enabled Minimum Base Fee (200,000 wei)	Minimum Base Fee
September 3, 2025	Enabled Per-Transaction Gas Maximum	Per-Transaction Gas Maximum
February 25, 2025	Enabled Flashblocks	Flashblocks