Base, the Coinbase-incubated Ethereum layer 2, says its fourth mainnet upgrade, Denim, is live and that it now produces a full block every 200 milliseconds, or five a second, The Block reports. The figures come from a statement the project shared on Thursday.
Denim retires Flashblocks and changes how the pending block tag works. Each block now follows its parent exactly 200 milliseconds later, and the protocol enforces that gap instead of the sequencer’s clock. Base calls block production simpler, more consistent and more reliable.
The cost falls on developers. Applications that relied on Flashblocks must move to standard canonical block subscriptions.
Denim is the fourth upgrade. Azul brought a new client stack and a multiproof system, Beryl the B20 token standard and Cobalt conditional transactions, and they were Base’s first independent upgrades since its 2023 launch.
Smart contracts gain BaseTime, which gives Unix timestamps in milliseconds, while the Ethereum-compatible block timestamp stays at whole seconds. New RPC fields add millisecond timestamps for blocks, transactions and logs.
The upgrade also tightens controls on B20 tokens, Base’s token standard. Compliance policies can be reused through a NOT operator, transfer-executor limits extend to direct transfers, and transfers, mints and seizures to a token contract’s own address are blocked.
Base says its aim is to bring the world onchain, starting with trading, financing and payments. The statement gives no activation block, no benchmarks and no migration deadline, so how many applications must rewrite their code is unknown.
