Coinbase's Base blockchain has completed the Denim upgrade and retired Flashblocks, requiring relevant applications to migrate their data routing. Base recently stated that the Denim upgrade went live on the mainnet on November 5, introducing full canonical blocks generated every 200 milliseconds. The Flashblocks data stream has been retired; while old WebSocket endpoints still accept connections, they no longer transmit data. Developers must migrate data routing to canonical blocks and RPC streams, and adjust how they handle pending block tags and transaction receipts.