Ethereum core developers and client teams have officially set the stage for the network’s next major protocol evolution, establishing a firm activation schedule for the Glamsterdam network upgrade. Building directly upon the technical groundwork laid by the preceding Fusaka upgrade, Glamsterdam represents a critical leap forward in Ethereum’s Layer 1 scaling roadmap. The upgrade introduces ambitious architectural overhauls—most notably enshrined proposer-builder separation and block-level access lists—alongside comprehensive adjustments to gas pricing and state growth mechanics designed to future-proof the global settlement layer.
According to the agreed deployment schedule, the Glamsterdam network upgrade is officially scheduled to activate on the Sepolia testnet at epoch 353,024, slot 11,296,768, which corresponds to October 6, 2026, at 13:53:36 UTC. While Sepolia is set to receive the upgrade first, activation timelines for other key testnets, such as Hoodi, as well as the Ethereum Mainnet, remain undecided and will be announced by core developers once client readiness is confirmed.
Node operators, infrastructure maintainers, and staking participants running infrastructure on Sepolia must prepare for the upcoming transition by updating both their execution layer and consensus layer client software well ahead of the scheduled slot. Compatible client releases are currently rolling out across the ecosystem, and operators are strongly advised to consult specific release notes to ensure full compatibility with the forthcoming fork rules.
Glamsterdam Overview and Core Architecture
The Glamsterdam upgrade is a unified milestone that harmonizes the Amsterdam execution layer upgrade with the Gloas consensus layer upgrade. Together, these complementary packages fundamentally reshape how Ethereum blocks are proposed, validated, executed, and stored. At the heart of Glamsterdam are two headlining changes: Enshrined Proposer-Builder Separation (ePBS) and Block-Level Access Lists (BALs). These two mechanisms work in tandem to dramatically boost Layer 1 execution capacity while keeping block validation practical, lightweight, and decentralized enough for independent node operators to maintain.
By modernizing the protocol’s core operational logic, Ethereum developers are addressing long-standing challenges related to MEV (Maximal Extractable Value) centralization, state bloat, and disk I/O bottlenecks. The upgrade sets a new standard for protocol efficiency, ensuring that the network can securely handle higher transaction throughput without compromising censorship resistance or validator decentralization.
Enshrined Proposer-Builder Separation (ePBS)
One of the most anticipated architectural changes included in Glamsterdam is Enshrined Proposer-Builder Separation, standardized via EIP-7732. For years, Ethereum has relied on out-of-protocol, trusted middleware mechanisms to manage the division of labor between block builders—who construct optimal transaction bundles—and block proposers, who validate and anchor blocks to the blockchain. EPBS brings this vital economic dynamic directly into Ethereum’s core consensus protocol.
Under the new EIP-7732 framework, a block proposer includes a builder’s cryptographic commitment to an execution payload within their consensus block. The builder subsequently reveals the full execution payload in a timely manner. The protocol natively handles the complex payment mechanics from the builder to the proposer, completely removing the reliance on trusted third-party relayers and out-of-protocol middleware for this exchange.
Furthermore, EPBS cleanly separates consensus validation from execution validation. This separation grants validator nodes significantly more breathing room and time to properly validate execution payloads. A specialized protocol participant group, known as the payload timeliness committee, actively attests to whether the builder successfully revealed its payload and whether the corresponding blob data was available on the network on time. Validator operators and engineering teams maintaining specialized builder infrastructure are urged to thoroughly review these new operational duties, cryptographic interfaces, and timing requirements prior to mainnet and testnet deployment.
Block-Level Access Lists (BALs)
Complementing ePBS is EIP-7928, which introduces enforced block-level access lists to the protocol. These access lists systematically record every account and storage location accessed throughout the lifecycle of a block, alongside all post-transaction state changes.
By making these access patterns explicit and mandatory at the block level, execution clients gain the ability to read state data from disk in parallel, validate incoming transactions concurrently, and compute state roots with vastly improved computational efficiency. Together, ePBS and block-level access lists establish a robust, scalable foundation for Ethereum’s execution capacity, solving some of the most stubborn performance bottlenecks associated with massive state growth.
Gas Pricing, Repricing, and State Growth Adjustments
Glamsterdam also introduces crucial adjustments to gas accounting designed to more accurately reflect the true resource consumption of transactions, particularly regarding state bloat. Specifically, EIP-8037 increases and separately meters the direct cost associated with creating new state, while EIP-8038 updates the general costs tied to state access. Additional refinements across the upgrade cover intrinsic transaction gas rules, calldata processing, access lists, and overarching block gas accounting.
These sweeping economic adjustments carry significant implications for application and smart contract developers. Developers are strongly encouraged to test their contracts, deployment scripts, and gas estimation logic against the new rules ahead of time. Contracts that rely on fixed gas stipends, hardcoded gas limits, or legacy assumptions about remaining execution gas may require targeted code modifications to function correctly after the upgrade. Ecosystem resources, including dedicated testing guides and affected-contract search utilities, have been published to help teams audit their codebases.
Beyond core repricing, Glamsterdam delivers several developer-focused improvements and utility enhancements. These include native ETH transfer logs, a dedicated slot-number opcode, an increased maximum contract size limit, a deterministic factory contract, and new low-level stack-manipulation instructions. Consensus-layer enhancements similarly feature forward-compatible data structures, the exclusion of slashed validators from proposing new blocks, and increased maximum exit and consolidation churn rates to improve staking queue fluidity.
Security, Bug Bounties, and Ecosystem Readiness
In alignment with Ethereum’s rigorous release standards, the official Ethereum Bug Bounty Program has been updated and expanded to cover all Glamsterdam specifications and associated EIPs. Client software implementations become formally eligible for bug bounty rewards as soon as their respective Sepolia-compatible releases are finalized and published. Security researchers and auditors analyzing the upgrade specifications can review the official Ethereum Bug Bounty documentation for details regarding reward multipliers, submission requirements, and vulnerability categories.
As the network approaches the October 6, 2026 activation timestamp on Sepolia, the broader community remains focused on coordinated testing. While standard ETH holders and decentralized finance users on Mainnet do not need to take any direct action for this testnet event, node operators, stakers, and infrastructure providers on Sepolia must ensure their execution and consensus layer clients are fully updated. Comprehensive release matrices and tracking resources continue to be updated by client maintainers as the community prepares to bring Glamsterdam to life.
Ethereum & Smart Contracts
Ethereum & Smart Contracts
Ethereum & Smart Contracts
