Ethereum’s Glamsterdam Network Upgrade Scheduled for Hoodi Testnet Following Sepolia Debut

Ethereum’s upcoming major network upgrade, dubbed "Glamsterdam," is continuing its methodical rollout across test networks. Following its initial activation on the Sepolia testnet on October 6, 2026, core developers have officially scheduled the upgrade to go live on the Hoodi testnet. The deployment on Hoodi is set for October 26, 2026, at 17:42:48 UTC, corresponding to epoch 132,352 and slot 4,235,264. Concurrently with this activation, the gas limit on the Hoodi testnet will be raised to 200 million, mirroring the adjustments previously made on Sepolia. While testnet testing is progressing rapidly, a definitive date for the Ethereum mainnet activation has not yet been finalized by client teams.

Node operators running clients on the Hoodi network must ensure they update both their execution layer and consensus layer software prior to the activation timestamp. Compatible client versions are being compiled and released, and network participants are strongly advised to monitor official distribution channels to verify that their chosen software explicitly supports the scheduled Glamsterdam upgrade.

Glamsterdam Overview and Core Architecture

The Glamsterdam upgrade represents a comprehensive overhaul of the Ethereum protocol, combining the Amsterdam execution layer upgrade with the Gloas consensus layer upgrade. Together, these two components introduce foundational changes designed to advance Ethereum’s layer-one scaling roadmap. The headlining features of the upgrade include enshrined proposer-builder separation (ePBS) and block-level access lists (BALs), both of which fundamentally alter how blocks are produced, transmitted, and validated across the decentralized network to support significantly higher transaction throughput.

Enshrined Proposer-Builder Separation, standardized under EIP-7732, brings the well-established separation between block proposers and specialized block builders directly into the core consensus protocol of Ethereum. Under this new mechanism, a block proposer includes a builder’s cryptographic commitment to an execution payload within a slot, and the builder subsequently reveals the full payload. The protocol natively handles the financial settlement and payment to the proposer, thereby mitigating reliance on trusted external middleware for the exchange between validators and builders.

Furthermore, EIP-7732 decouples consensus validation from execution validation. This structural shift grants validators substantially more time to verify execution payloads before attesting to a block. A dedicated payload timeliness committee is established to attest to whether the builder successfully revealed its payload and whether the corresponding data blobs were made available on time. Validator operators and engineering teams maintaining builder infrastructure are required to thoroughly review these new operational duties and software interfaces ahead of the mainnet release.

Block-Level Access Lists and State Growth Management

Complementing ePBS are block-level access lists introduced via EIP-7928. These enforced lists systematically record the specific accounts and storage locations accessed over the course of a block, alongside the resulting post-transaction state changes. By providing this deterministic data upfront, client software is empowered to read state information from disk in parallel, validate incoming transactions concurrently, and compute state roots with a much higher degree of computational efficiency.

In tandem with structural changes to block validation, Glamsterdam introduces critical adjustments to gas pricing and state growth mechanics. EIP-8037 increases and separately meters the financial and computational cost of creating new state on the network, while EIP-8038 updates broader state-access costs. Additional modifications cover intrinsic transaction gas, calldata processing, access lists, and overall block gas accounting. These economic adjustments are carefully calibrated to ensure that gas pricing accurately reflects the true resource usage and long-term cost of state bloat for node operators.

Application developers are strongly encouraged to test their smart contracts and gas estimation logic against these updated protocol rules. Contracts that rely heavily on fixed gas stipends, hardcoded gas limits, or legacy assumptions about remaining execution gas may require targeted modifications to function correctly under the new pricing environment. Comprehensive testing guides and impact documentation have been published by the developer community to help teams identify affected contracts prior to mainnet deployment.

Developer Improvements and Protocol Specifications

Beyond scaling and economic adjustments, the Glamsterdam upgrade delivers a robust suite of improvements for application developers and validators alike. These additions include native Ethereum transfer logs, a dedicated slot-number opcode, an increased maximum contract size limit, a standardized deterministic factory contract, and new stack-manipulation instructions designed to streamline smart contract development. On the consensus side, the upgrade incorporates forward-compatible data structures, implements rules to exclude slashed validators from participating in block proposals, and increases the allowable exit and consolidation churn rates for stakers.

Tracking under EIP-7773, the Glamsterdam specification encompasses a wide array of execution and consensus layer changes, alongside supporting networking and informational enhancements. Comprehensive details regarding the scheduled Ethereum Improvement Proposals are maintained within the official repository specifications.

Security and the Ethereum Bug Bounty Program

To ensure the resilience of the upgrade, the Ethereum Bug Bounty Program remains fully active for all Glamsterdam specifications and associated EIPs. Client implementations become eligible for bug bounty rewards as soon as their respective releases are officially published and integrated into the upgrade release tables. Security researchers and developers are encouraged to review the official Ethereum bug bounty guidelines for detailed information regarding reward multipliers, submission requirements, and vulnerability reporting procedures.

Activation Schedule and Client Releases

The agreed deployment schedule for the Glamsterdam network upgrade follows a structured path from testnets to mainnet. Following the successful activation on Sepolia at epoch 353,024, attention now shifts entirely to Hoodi. The Hoodi activation will occur at epoch 132,352, slot 4,235,264, on October 26, 2026, at 17:42:48 UTC, utilizing UNIX timestamp 1793036568. At this precise epoch, the gas limit on Hoodi will increase to 200 million. Mainnet activation remains undetermined, and client teams will announce a formal schedule once testnet stability has been thoroughly evaluated.

Node operators must verify that they are utilizing compatible client versions. For consensus layer participants operating validators, both the beacon node and the validator client software must be updated simultaneously. Similarly, execution layer clients require timely updates to align with the new block validation rules and gas pricing structures. Operators utilizing external builder infrastructure or specialized tooling should also cross-reference release notes for compatibility updates, such as those provided for auxiliary tooling like commit-boost.

Frequently Asked Questions

Network upgrades on Ethereum rely fundamentally on explicit, voluntary opt-in from node operators across the ecosystem. Client developers coordinate the underlying protocol changes, while validators and non-staking node operators independently update their software to adopt the new rules. Because nodes running outdated software cannot follow the upgraded chain after activation, maintaining coordinated upgrade schedules is vital for network continuity.

For ordinary Ethereum mainnet users and ETH holders, no direct action is required in response to the Hoodi announcement, as the changes are currently restricted to test environments. Mainnet users will receive ample notice ahead of the mainnet deployment. Similarly, non-staking Hoodi node operators simply need to update their execution and consensus software prior to the October 26 activation timestamp.

Stakers on the Hoodi testnet face more rigorous responsibilities, requiring both beacon node and validator client upgrades, alongside a review of new ePBS duties and gas limit configurations. Application and tooling developers are likewise advised to test their decentralized applications against the new gas pricing rules and state-growth parameters to ensure seamless compatibility when the changes eventually reach the mainnet.