Base has unveiled Vibenet, an ephemeral developer preview network with chain ID 84538453, to test three upgrades together before deployment on Sepolia and mainnet: 200-millisecond preconfirmations, native account abstraction through EIP-8130 and lower gas fees. Vibenet uses Flashblocks, developed with Flashbots, to send 10 incremental state updates during each two-second block window. Base is targeting the Denim upgrade for late August 2026, when incremental preconfirmations would give way to full canonical 200-millisecond blocks. The September 2026 Cobalt upgrade is expected to build on Denim’s results, although finalized activation dates for Sepolia and mainnet have not been announced. EIP-8130 makes account abstraction a protocol-level feature instead of relying on smart-contract infrastructure such as ERC-4337. Base says simple USDC transfers under EIP-8130 cost approximately 63% less than equivalent ERC-4337 transactions. Developers can use Vibenet’s faucet and block explorer to evaluate the features before broader deployment.