The Arbitrum network has successfully activated the ArbOS Dia upgrade on its primary layer-2 chains, Arbitrum One and Arbitrum Nova. This major protocol update is designed to deliver a more predictable and efficient user experience by fundamentally overhauling the network's gas pricing mechanism and introducing new developer tooling.
A core focus of the upgrade is smoothing out the notorious fee spikes that occur during periods of high network demand. Dia replaces the previous single gas target and adjustment window with multiple higher targets across longer windows. This change aims to reduce the severity, frequency, and duration of high fees. Additionally, the default minimum base fee on the L2 has been doubled from 0.01 gwei to 0.02 gwei. According to the Arbitrum team, this higher floor is intended to price out spam-style bot activity and help balance DAO revenue as the overall fee curve becomes more stable.
On the technical front, Dia updates the state transition function to track gas usage across specific resource types—computation, storage access, storage growth, and history growth—laying the groundwork for higher throughput on existing hardware. It also adjusts block packing rules, allowing the final transaction in a block to use up to the MaxTxGasLimit, which may slightly exceed the previous per-block limit without changing overall network targets.
For developers and user onboarding, the upgrade is significant. It brings secp256r1 support into alignment with Ethereum's planned post-Fusaka specifications, enabling native support for passkeys. This allows application teams to build authentication flows that use biometrics (like Face ID or fingerprint), device-secured keys, and enterprise-grade recovery systems.
Furthermore, Dia introduces Native Token Mint/Burn functionality for custom Arbitrum chains (though not for Arbitrum One). This feature enables these chains to delegate minting and burning to trusted bridge providers, broadening interoperability for native gas tokens. Supported standards include LayerZero OFTs, xERC20s, and native versions of USDC and USDT (USDT0). The upgrade also incorporates several Fusaka-era EVM changes, including new opcodes and updated cryptography semantics.
The Arbitrum team noted that a more advanced, dynamic constraint-based pricing model is not yet enabled and will be part of a future ArbOS release following further benchmarking and testing.
