Ethereum developers and core protocol maintainers have officially announced the upcoming deployment schedule for the "Glamsterdam" network upgrade, marking another significant milestone in the blockchain’s Layer 1 scaling roadmap. Building directly upon the foundational advancements introduced in the previous Fusaka upgrade, Glamsterdam is scheduled to activate on the Sepolia testnet at epoch 353,024, corresponding to slot 11,296,768. The activation is officially set for October 6, 2026, at precisely 13:53:36 UTC, initiating a crucial testing phase before the upgrade eventually transitions to other testnets and, ultimately, the Ethereum mainnet.
Node operators, validators, and infrastructure maintainers across the ecosystem have been strongly advised to review their systems and prepare to update both their execution layer and consensus layer clients well ahead of the scheduled activation timestamp. While Sepolia has its concrete activation coordinates locked in, deployment dates for other public testnets, such as Hoodi, as well as the Ethereum mainnet itself, remain undecided and will be announced by core client teams at a later date once testnet stability and performance metrics have been thoroughly evaluated.
Glamsterdam Overview
The Glamsterdam network upgrade represents a comprehensive synchronization of Ethereum’s core architecture by seamlessly combining the Amsterdam execution layer upgrade with the Gloas consensus layer upgrade. Together, these two synchronized components introduce sweeping changes designed to optimize how blocks are produced, transmitted, and validated across the network. At the very heart of this ambitious upgrade are two headline features: enshrined proposer-builder separation, commonly referred to as ePBS, and block-level access lists. These architectural modifications fundamentally alter block creation mechanics to support substantially higher Layer 1 throughput without compromising decentralization or overburdening individual node operators.
Enshrined Proposer-Builder Separation
One of the most consequential structural shifts introduced in Glamsterdam is the implementation of enshrined proposer-builder separation via EIP-7732. Historically, the separation of block proposers and block builders has relied heavily on external, trusted middleware protocols to facilitate transactions and trades. EIP-7732 brings this critical economic and technical separation directly into the core consensus protocol of Ethereum itself. Under the new mechanism, a block proposer includes a builder’s cryptographic commitment to an execution payload, and the builder subsequently reveals that payload within a strictly regulated protocol window.
Crucially, the protocol itself natively handles the payment distribution to the proposer, effectively eliminating the reliance on third-party middleware and reducing trust assumptions in the block-building supply chain. Furthermore, this update cleanly decouples consensus validation from execution validation, granting network validators significantly more time to thoroughly review and validate execution payloads. To ensure reliability, a newly established payload timeliness committee will actively attest to whether the builder successfully revealed its payload and whether the corresponding blob data was made available on time. Validator operators and engineering teams maintaining builder infrastructure are required to familiarize themselves with these new operational duties and interfaces prior to the upgrade.
Block-Level Access Lists
Complementing ePBS are block-level access lists, introduced via EIP-7928. This protocol change enforces structured lists that meticulously record the specific accounts and storage locations accessed over the course of a block, alongside the corresponding post-transaction state changes. By providing explicit visibility into state interaction before execution, these access lists empower client software to read state data from disk in parallel, validate transactions simultaneously rather than sequentially, and compute state roots with vastly improved computational efficiency. Together, enshrined proposer-builder separation and block-level access lists establish a robust, future-proof foundation for scaling Ethereum’s execution capacity while ensuring that day-to-day block validation remains practical and accessible for independent node operators running hardware of modest specifications.
Gas Pricing and State Growth
Glamsterdam also introduces a comprehensive overhaul of gas accounting to ensure that transaction fees more accurately reflect the true resource consumption of network operations. Specifically, EIP-8037 increases and separately meters the financial and computational cost associated with creating new state, while EIP-8038 updates general state-access costs. Additional adjustments encompass intrinsic transaction gas limits, calldata processing, access list overhead, and overall block gas accounting mechanics.
Application developers and smart contract engineers must thoroughly test their decentralized applications, automated contracts, and gas estimation logic against these updated rules. Contracts that heavily depend on fixed gas stipends, hardcoded gas limits, or rigid assumptions regarding remaining execution gas may experience unexpected failures and will likely require code modifications. Development teams are encouraged to consult the official Glamsterdam repricing impact guide, which provides dedicated tools for searching affected contracts and comprehensive testing guidance to ensure a smooth transition.
Developer and Validator Improvements
Beyond its major scaling components, Glamsterdam bundles several targeted enhancements for both application developers and consensus participants. The upgrade introduces native ETH transfer logs, a dedicated slot-number opcode to simplify contract logic, an increased maximum contract size limit, a deterministic factory contract to streamline deployments, and brand-new stack-manipulation instructions. On the consensus side, protocol changes feature forward-compatible data structures, technical mechanisms to explicitly exclude slashed validators from proposing new blocks, and increased churn limits for validator exits and network consolidations.
Glamsterdam Security
In alignment with Ethereum’s rigorous release standards, the official Ethereum Bug Bounty Program is active for all Glamsterdam specifications and associated EIPs. Individual client implementations become officially eligible for bounty rewards as soon as their respective software releases are formally incorporated into the network’s client release tables. Security researchers and auditors looking to examine the upcoming changes can reference the Ethereum Bug Bounty Program documentation for detailed information regarding reward multipliers, severity classifications, and submission reporting requirements.
Client Releases and Operational Guidelines
With the Sepolia activation officially scheduled for October 6, 2026, node operators must ensure they are running compatible software versions. For consensus layer operations on Sepolia, operators running validators must remember to update both their Beacon Node and their corresponding Validator Client. Specific client implementations have introduced unique configuration nuances that operators must account for. For instance, Prysm version 7.2.0 natively supports the Sepolia fork but defaults to a conservative 60 million gas limit following activation. Validators who wish to propose blocks with a higher 200 million gas limit must configure this setting explicitly through version 2 proposer settings or the keymanager API, as legacy command-line flags like the suggested gas limit will have no effect after the activation of Gloas. Similarly, Teku version 26.9.1 supports the Sepolia fork with a default 60 million gas limit, requiring operators to explicitly apply specific command-line configurations if they intend to utilize a 200 million gas limit.
Execution layer clients are rolling out their own Sepolia-compatible releases, and operators using external block-building infrastructure must carefully review provider-specific instructions. Because network upgrades require absolute synchronization, operators must verify that their chosen software release explicitly confirms support for the scheduled Glamsterdam activation on Sepolia.
Frequently Asked Questions
As the community prepares for the deployment, core developers have addressed common inquiries regarding the nature of network upgrades. Ethereum upgrades rely entirely on explicit, voluntary opt-in from the broader community of node operators. Core client developers coordinate the underlying protocol specifications, while validators and non-staking node operators independently choose to update their software to adopt the new rules. Any node that fails to update cannot follow the upgraded chain after activation, underscoring the vital importance of widespread coordination.
For ordinary Ethereum mainnet users, holders of ETH, and individuals interacting with decentralized applications, no direct action is required for this initial testnet announcement, as mainnet activation remains scheduled for a future date. Non-staking Sepolia node operators and active stakers, however, must ensure their execution and consensus clients are fully updated prior to the October 6 deadline, making certain that both beacon nodes and validator clients reflect the necessary patches. Application developers are similarly urged to review the scheduled EIPs, test their smart contracts on Sepolia post-activation, and account for any modifications to gas accounting, opcodes, or logging structures to guarantee uninterrupted performance when the upgrade eventually reaches production environments.
Ethereum & Smart Contracts
Ethereum & Smart Contracts
Ethereum & Smart Contracts
