Base, the Layer 2 blockchain incubated by Coinbase, activated its Azul network upgrade on Mainnet this month, marking the chain’s first independent protocol upgrade and a major step toward Phase 2 decentralization.
The upgrade launched on the Base Sepolia testnet on April 21 and targeted the mainnet on May 13, according to a blog post published that day by the Base engineering team. Multiproofs went live on Mainnet on May 21, it was confirmed in a follow-up post.
Azul’s most significant change is the activation of multiproofs, a system that combines TEE (Trusted Execution Environment) proofs and Zero-Knowledge (ZK) proofs into a single proof architecture.
Both types of proofs can independently complete a block proposal, but if they both agree, withdrawals from Base to Ethereum can be completed in one day. ZK proofs overwrite TEE proofs if the two contradict each other, and conflicting proofs trigger an automatic validity warning that disables the corresponding prover. The design is modeled after a finalization roadmap proposed by Vitalik Buterin, co-founder of Ethereum.
Base currently has $4.38 billion in total value locked, supports $1.37 billion in daily DEX volume, and hosts $4.66 billion in on-chain stablecoin market cap, according to DefiLlama data.
Phase 2
Buterin’s decentralization framework for Layer 2 networks defines Phase 2 as the point at which a chain can detect and handle proof system bugs in the chain without relying on a privileged security council to intervene. Base reached Phase 1 in April 2025, when it established a decentralized Security Council to approve upgrades. Error proofs, which allow any user to dispute an incorrect status claim, were activated in October 2024.
Multiproofs meet a core technical requirement for Phase 2 by enabling onchain detection of bugs in the proof system. The ZK component uses SP1, a prover developed by Succinct Labs, which Base cited for its performance and audit history. The system is designed so that a compromise of fast capture requires an attacker to defeat multiple independent evidence systems simultaneously.
Before the upgrade, Base hosted an audit competition on Immunefi from April 21 to May 4 with a maximum reward pool of $250,000 for critical vulnerabilities reported in the testnet code.
Customer consolidation and performance
Azul consolidates Base onto a single client stack. The upgrade ends support for all execution and consensus clients except base-reth-node, an execution client based on Reth and one of Ethereum’s best performing clients, and base-consensus, a new consensus client built on the Kona framework. Base said the consolidation aims to pave the way to a throughput of 1 gigagram per second.
In the two months leading up to Azul’s launch, Base said it reduced empty blocks by about 99%, from about 200 per day to about two, and endured multiple bursts of 5,000 transactions per second.
Node operators must migrate to the new client stack before the network upgrade is activated. Step-by-step instructions are available in the Base Node Operator Upgrade Guide.
Azul also aligns Base with Ethereum’s latest execution layer specification, known as Osaka. The changes include EIP-7825, which introduces a per-transaction gas limit of approximately 17 million gas to support future validator performance.
What comes next
Base outlined two additional upgrades planned for the coming months. A performance-based upgrade targeted for late June is expected to include a committed token standard, Flashblock access lists, Glamsterdam EIPs, a single combined client binary, and faster recording times. A second upgrade, targeted for late August, would introduce native account abstraction.
Base also plans to launch Base Vibenet in mid-May, a public development net that will allow developers to experiment with upcoming features ahead of the mainnet. Base described Vibenet as a permanent testing environment that is not tied to a specific hard fork.