Ethereum’s ambitious scaling roadmap is moving closer to reality as core developers and protocol maintainers lock in the details for the next major network upgrade. Following its successful deployment on the Sepolia testnet on October 6, the Glamsterdam network upgrade has officially been scheduled for activation on the Hoodi testnet. The upgrade brings a sweeping set of protocol changes aimed at enhancing Layer 1 throughput, restructuring how blocks are built and validated, and adjusting gas pricing mechanics to better reflect the true costs of resource execution and state growth.
According to the official coordination schedule, Glamsterdam will activate on the Hoodi testnet at epoch 132,352, corresponding to slot 4,235,264. This milestone is slated to occur on October 26, 2026, at exactly 17:42:48 UTC. Simultaneously at this epoch, Hoodi’s gas limit will be increased to 200 million, mirroring the adjustments previously rolled out on Sepolia. While testnet deployments are accelerating, a definitive mainnet activation date has not yet been finalized by client teams and will be announced once developers are confident in the stability and performance of the testnet environments.
Ahead of the activation window, node operators are instructed to update both their execution layer and consensus layer clients to compatible versions as they are released. Maintaining an un-upgraded node will result in clients becoming incompatible with the network once the upgrade takes effect, cutting them off from the post-upgrade chain.
Glamsterdam Overview
The Glamsterdam upgrade represents a comprehensive convergence of execution layer modifications—traditionally named after Devcon and Devconnect host cities, drawing inspiration from Amsterdam where Devconnect took place in 2022—and consensus layer updates, which follow star naming conventions under the moniker Gloas. By combining these efforts, the upgrade introduces structural solutions designed to alleviate bottlenecks on the Ethereum network.
At the core of Glamsterdam are two headlining architectural changes: enshrined proposer-builder separation and block-level access lists. Together, these modifications fundamentally alter how blocks are produced, broadcast, and verified across the network, laying a robust foundation for scaling Ethereum’s execution capacity while ensuring that validating blocks remains practically manageable for individual node operators.
Enshrined Proposer-Builder Separation
One of the most significant changes introduced by Glamsterdam is enshrined proposer-builder separation, commonly referred to as ePBS and detailed under EIP-7732. Until now, the separation of block proposers and builders relied heavily on out-of-protocol, trusted middleware infrastructure to coordinate the exchange of blocks and execution payloads.
By bringing this separation directly into Ethereum’s core consensus protocol, the network standardizes the interaction. Under the new mechanism, a block proposer includes a builder’s commitment to an execution payload, and the builder subsequently reveals that payload. The underlying protocol natively handles the payment transfer from the builder to the proposer, substantially reducing reliance on third-party trusted intermediaries.
Furthermore, ePBS separates consensus validation duties from execution validation duties. This architectural shift grants validators additional, much-needed time to thoroughly validate execution payloads. To ensure accountability, a dedicated payload timeliness committee actively attests to whether builders successfully reveal their payloads and whether corresponding blob data remains available on time within the required window. Validator operators and engineering teams maintaining specialized builder infrastructure are strongly advised to review these updated duties and interfaces well ahead of the upgrade.
Block-Level Access Lists
Complementing ePBS is the introduction of block-level access lists, established via EIP-7928. These enforced lists explicitly record the specific accounts and storage locations accessed over the course of a given block, alongside the corresponding post-transaction state changes.
By providing pre-vamped visibility into state dependencies, block-level access lists allow client software to read state from disk in parallel, validate incoming transactions simultaneously rather than sequentially, and compute state roots with greater computational efficiency. This optimization is critical for maintaining high throughput without sacrificing decentralization or overwhelming client hardware.
Gas Pricing and State Growth
Glamsterdam also tackles the ongoing challenge of state growth by overhauling gas accounting rules to better align with actual resource utilization. Through EIP-8037, the network increases and separately meters the cost associated with creating new state, discouraging unnecessary bloat. Meanwhile, EIP-8038 updates baseline state-access costs. Additional adjustments span intrinsic transaction gas, calldata handling, access lists, and broader block gas accounting.
Application developers are urged to rigorously test their smart contracts and gas estimation logic against these updated rules. Contracts that rely on fixed gas stipends, hardcoded gas limits, or outdated assumptions regarding remaining gas may experience unexpected behavior and may require code modifications. Comprehensive search tools and testing guidance are available through the official Glamsterdam repricing impact documentation to help developers identify vulnerable contracts.
Beyond these major pillars, the upgrade incorporates several developer and validator enhancements, including native Ethereum transfer logs, a dedicated slot-number opcode, an increased maximum contract size limit, a deterministic factory contract, and new stack-manipulation instructions. Consensus-layer adjustments include forward-compatible data structures, the exclusion of slashed validators from proposing new blocks, and increases to the exit and consolidation churn rates.
Glamsterdam Security
To ensure the robustness of the upgrade, the Ethereum Bug Bounty Program remains active for all Glamsterdam specifications and associated EIPs. Individual client implementations become eligible for bounty rewards as soon as their respective releases are officially incorporated into the network’s client release tables. Security researchers and developers are encouraged to review the official Ethereum Bug Bounty documentation for complete details regarding reward multipliers, scope definitions, and submission reporting requirements.
Glamsterdam Activation
The agreed deployment schedule places the Hoodi testnet activation at epoch 132,352 and slot 4,235,264, scheduled for October 26, 2026, at 17:42:48 UTC, following Sepolia’s earlier activation on October 6. Hoodi’s gas limit will simultaneously scale to 200 million via the EIP-8261 schedule. Mainnet deployment timelines remain contingent on testnet performance and will be formally scheduled by core developers once readiness is confirmed.
Node operators running clients on Hoodi must ensure they utilize versions explicitly verified to support the upgrade. Consensus layer users operating validators must remember to update both their beacon nodes and validator clients simultaneously to prevent missed attestations or slashing risks. Mainnet users and holders of ETH do not need to take any immediate action, as network upgrades only require direct intervention from infrastructure operators and developers.
Ethereum & Smart Contracts
Ethereum & Smart Contracts
Ethereum & Smart Contracts
