Base's Cobalt Upgrade Adds Seizure Controls to B20 Token Balances
Base's Cobalt upgrade is set to add new rules governing token balances for B20 issuers. Scheduled for mainnet deployment on September 30 at 18:00 UTC, the update introduces separate administrative seizure controls that allow reassignment of holder balances under different permissions.
The feature, which will be optional for B20 issuers, lets them configure balance seizures separately from ordinary transfer restrictions. This means a token holder could remain free to transfer while still being eligible for administrative reassignment.
According to Base's documentation, the existing blocked-account burn remains callable and continues to destroy tokens, but reassignment preserves total supply.
The Cobalt upgrade also includes other changes, such as marking the burnBlocked function as deprecated. However, it will remain callable with its existing behavior, leaving issuers with different ways to remove a holder's balance, either through reassignment or destruction of the seized supply.