Lagoon

Hardfork registry entry for the Lagoon network upgrade, which activates Superchain interop.

Lagoon is the upcoming hardfork that activates Superchain interop. No superchain-wide activation defaults are set in the superchain-registry yet; the first activations are being prepared per chain — see the interop activation prep notice for OP Sepolia and Unichain Sepolia.

Status	In development
Governing spec	specs.optimism.io
Operator notice	View notice
Mainnet activation (superchain default)	Not scheduled
Sepolia activation (superchain default)	Not scheduled

What’s included

Per the spec overview (subject to change while the spec is in development):

• Interop: dependency set, cross-chain messaging, derivation, sequencer and verifier behavior, super roots, interop fault proofs, and the interop bridging contracts.
• Execution layer: post-execution transactions and sequencer-defined metering.