Ethereum Sets Hoodi Testnet Activation for Glamsterdam Upgrade Following Sepolia Rollout

Following its successful deployment on the Sepolia testnet earlier this month, the highly anticipated Glamsterdam network upgrade is officially marching toward its next major milestone. Core developers and client teams have scheduled the upgrade to activate on the Hoodi testnet at epoch 132,352, corresponding to slot 4,235,264, which is set to occur on October 26, 2026, at 17:42:48 UTC. Alongside this activation, the Hoodi network’s gas limit will be substantially raised to 200 million, mirroring the adjustments previously made on Sepolia. While the testnet rollout is moving forward rapidly, the official mainnet activation date remains undetermined, pending further stability assessments and coordination among client teams.

The Glamsterdam network upgrade represents a massive step forward in Ethereum’s Layer 1 scaling roadmap, combining the Amsterdam execution layer upgrade with the Gloas consensus layer upgrade. Together, these modifications introduce profound structural changes designed to enhance network throughput, streamline validation processes, and better align gas pricing with actual resource consumption and state growth. Node operators running infrastructure on Hoodi must ensure they update both their execution and consensus layer clients well before the specified activation time to maintain synchronization with the upgraded network. Compatible client software versions are currently being rolled out and cataloged by development teams.

At the heart of the Glamsterdam upgrade is the introduction of Enshrined Proposer-Builder Separation, commonly referred to as ePBS under EIP-7732. This pivotal protocol change integrates the separation of block proposers and builders directly into Ethereum’s core consensus mechanism. Previously, this relationship relied heavily on trusted external middleware. Under the new protocol framework, a block proposer includes a builder’s cryptographic commitment to an execution payload, and the builder subsequently reveals that payload. Furthermore, the system establishes a direct protocol-level payment mechanism to the proposer.

By decoupling consensus validation from execution validation, ePBS grants validators significantly more breathing room to meticulously review execution payloads. A dedicated payload timeliness committee will now attest whether builders successfully reveal their payloads and ensure that corresponding blob data is published on schedule. Validator operators and engineering teams maintaining builder infrastructure are strongly advised to thoroughly review these new operational duties and updated interfaces ahead of the upgrade.

Complementing ePBS is the introduction of Block-Level Access Lists via EIP-7928. These enforced lists meticulously record every account and storage location accessed throughout the lifecycle of a block, alongside the resulting post-transaction state changes. By providing explicit visibility into state interactions upfront, client software can read data from disk in parallel, execute transaction validations concurrently, and compute state roots with unprecedented efficiency. Together, enshrined proposer-builder separation and block-level access lists establish a robust architectural foundation for scaling Ethereum’s execution capacity without compromising the hardware accessibility required for practical node operation.

The upgrade also tackles the long-term challenge of state bloat through comprehensive gas pricing and economic adjustments. EIP-8037 increases and separately meters the financial cost associated with creating new state, while EIP-8038 updates general state-access costs. Additional adjustments encompass intrinsic transaction gas consumption, calldata pricing, access lists, and overarching block gas accounting. These modifications ensure that network fees accurately reflect the true resource burdens placed on validators. Application developers are strongly encouraged to test their smart contracts and gas estimation logic against these revised rules well in advance, as contracts relying on fixed gas stipends or hardcoded gas assumptions may require refactoring.

Beyond its core scaling and economic mechanisms, Glamsterdam introduces a broad suite of developer and validator enhancements. These include native Ethereum transfer logs, a dedicated slot-number opcode, an expanded maximum contract size limit, a deterministic factory contract, and advanced stack-manipulation instructions. On the consensus side, the upgrade incorporates forward-compatible data structures, implements rules to exclude slashed validators from the proposal queue, and increases the churn limit for validator exits and consolidations to improve network fluidity.

Security remains a paramount priority as the upgrade approaches its testnet deployment. The Ethereum Bug Bounty Program is officially active for all Glamsterdam specifications and associated EIPs. Individual client implementations become eligible for bug bounty rewards as soon as their respective release versions are officially published and verified. Node operators and stakers participating in the Hoodi testnet deployment must ensure that both their consensus layer beacon nodes and validator clients are fully updated before the scheduled epoch. The developer community will continue to monitor network stability on Hoodi as the October 26 activation date approaches, paving the way toward eventual mainnet scheduling discussions.