In brief
- Base activated its Cobalt upgrade on mainnet on 30 September, a week after it went live on the Sepolia testnet.
- The B20 token standard gains combined compliance rules, scheduled stock-split style adjustments and an opt-in seize function for issuers.
- New Validity Transactions let users sign a transaction that Base only includes once set onchain conditions are met.
Base, the Ethereum layer-2 network incubated by Coinbase, switched on its Cobalt upgrade on 30 September. According to the Cobalt overview in Base’s documentation, the upgrade extends the chain’s B20 token standard and adds conditional transactions, along with two changes to how nodes are upgraded and how secure-enclave signers are registered.
Cobalt is Base’s third network upgrade. It follows Beryl, which brought B20 to mainnet on 25 June as a token standard built into the node software rather than deployed as a smart contract. Base pitched it at issuers of stablecoins and tokenized real-world assets.
What changes for B20 issuers?
The first change is composite policies. An issuer can now combine two to four existing allowlists or blocklists under an AND or OR rule, for example requiring that a holder is on a KYC allowlist and not on a sanctions blocklist. Before Cobalt, issuers had to copy those lists into one flattened list and keep it in sync with offchain software, which Base’s composite policy changelog says could go stale. Every check now reads the current state of each list.
Second, B20 asset issuers can schedule a multiplier update for a corporate action such as a stock split, a routine event for issuers of tokenized stocks. Wallets and apps then show a different unit count from a set time, while the raw balances stay unchanged. The feature follows the ERC-8056 “Scaled UI Amount” proposal.
Third, a new function, seizeWithMemo, lets an administrator holding a dedicated seize role move a holder’s balance to another address and attach a note that is recorded onchain. The seize documentation calls it “a transfer, not a burn”: total supply stays the same. It replaces burnBlocked, the Beryl tool that could only destroy a blocked holder’s tokens, which is deprecated but still callable.
Seizing is opt-in per token. It does nothing until the issuer sets a policy naming which accounts can be seized, and a token that never sets one has no seize capability. Base said in its announcement that the issuer decides whether the feature is on and who may use it, and that Base itself does not start such transfers.
How Validity Transactions work
Validity Transactions let a user submit a signed transaction together with conditions on account balances, contract storage, block numbers or Flashblock positions. Base only considers it for a block once every condition matches. A swap that executes only after a pool price passes a threshold is the standard example. The conditions are sent separately and do not appear in the final onchain transaction, and Base says submissions stay private until they land. The Validity Transactions specification adds that a matching transaction is not guaranteed a place in a block.
The next items on Base’s list are faster blocks and simpler fees. Base says it plans to cut block times from two seconds to 200 milliseconds in the coming months and to add native support for sponsored fees and bundled transactions.
