Ethereum Announces Glamsterdam Network Upgrade to Enhance Scalability and Infrastructure Efficiency

Ethereum developers have officially confirmed the upcoming deployment of the Glamsterdam network upgrade, a significant technical milestone that marks the next phase of the network’s long-term Layer 1 scaling roadmap. Building upon the progress made during the previous Fusaka upgrade, Glamsterdam introduces foundational changes to the protocol’s core architecture, including Enshrined Proposer-Builder Separation (ePBS) and the implementation of block-level access lists. The upgrade is scheduled to activate on the Sepolia testnet at epoch 353,024, corresponding to slot 11,296,768, on October 6, 2026, at 13:53:36 UTC. While Sepolia serves as the testing ground, timelines for the Hoodi testnet and the Ethereum mainnet remain under development, with further details expected from client teams in the coming months.

The Glamsterdam upgrade represents a deliberate effort to solve long-standing bottlenecks in how blocks are produced, validated, and processed. By integrating the Amsterdam execution layer improvements with the Gloas consensus layer advancements, the upgrade addresses the increasing demands placed on node operators as the network grows. The primary objective is to improve the protocol’s throughput and resource management while maintaining the decentralization and security that are central to Ethereum’s ethos.

Technical Evolution: The Mechanics of ePBS and Access Lists

At the heart of the Glamsterdam upgrade is EIP-7732, which formally enshrines Proposer-Builder Separation (ePBS) into the consensus protocol. Historically, Ethereum has relied on external, trusted middleware to facilitate the exchange between block proposers (validators) and block builders (specialized entities that construct high-value blocks). By bringing this process into the protocol itself, Ethereum reduces the trust assumptions required for this relationship. A proposer will now include a builder’s commitment to an execution payload, and the builder will reveal that payload subsequently. This mechanism ensures that the protocol handles the payment to the proposer directly, creating a more robust and permissionless environment.

Furthermore, ePBS introduces a crucial separation between consensus validation and execution validation. Under the current structure, validators are often under extreme time pressure to verify both consensus-level data and the execution payload. Glamsterdam provides validators with additional time to perform these duties, supported by a "payload timeliness committee" that verifies if the builder successfully revealed the payload and associated blob data within the required timeframe. This structural change is expected to lower the barrier to entry for solo validators and improve the overall reliability of block production.

Complementing ePBS is the introduction of block-level access lists (BALs) via EIP-7928. This update mandates that every block contains a list of the accounts and storage locations accessed during its lifecycle, along with post-transaction state changes. This is not merely a bookkeeping change; it is a fundamental shift that enables clients to read state data from disk in parallel. By allowing clients to validate transactions and compute state roots concurrently rather than sequentially, the network can achieve significantly higher efficiency. These changes collectively provide a scalable foundation that allows the network to handle increased activity without placing undue stress on node operators’ hardware requirements.

Adjusting the Economic Model: Gas Pricing and State Growth

Resource management is a persistent challenge for a decentralized network. As the Ethereum state database expands, the cost of storage and computation must be balanced to ensure that node operation remains accessible. Glamsterdam introduces a series of repricing measures, most notably EIP-8037 and EIP-8038, which adjust gas accounting to better reflect actual resource usage. EIP-8037 specifically increases the cost of state creation, while EIP-8038 updates the costs associated with state access.

These adjustments are intended to curb the growth of the state database—the "bloat" that can slow down node synchronization and increase hardware costs over time. By accurately pricing the cost of writing to the state, the network discourages inefficient contract behavior and incentivizes developers to optimize their code. For application developers, these changes necessitate a proactive approach. Contracts that rely on hardcoded gas limits or fixed stipends may experience breaking changes upon the activation of these new rules. Consequently, the Ethereum Foundation and client teams have released a detailed "Glamsterdam Repricing Impact Guide" to assist developers in identifying and auditing potentially affected smart contracts.

The Road to Deployment: Coordination and Timeline

The activation of Glamsterdam on the Sepolia testnet is the critical first step in the deployment lifecycle. Following the standard Ethereum upgrade procedure, node operators are required to update both their execution layer and consensus layer clients to versions that support the Glamsterdam fork. The importance of this coordination cannot be overstated; because Ethereum is a decentralized network, it relies on the voluntary participation of operators to adopt protocol changes. Nodes that do not update will find themselves on a legacy fork, effectively losing their connection to the main network.

The current schedule for the Sepolia activation is as follows:

• Network: Sepolia Testnet
• Activation Epoch: 353,024
• Activation Slot: 11,296,768
• Scheduled Time: October 6, 2026, 13:53:36 UTC
• UNIX Timestamp: 1791294816

Client teams, including those behind Geth, Nethermind, Besu, Prysm, Teku, and Lighthouse, are in the process of finalizing their respective releases. For example, Prysm and Teku have already noted specific configurations for gas limits that validators must be aware of. The requirement to explicitly configure a 200M gas limit for those who wish to utilize it underscores the level of granular control the Glamsterdam upgrade provides to participants.

Broader Implications and Developer Responsibility

While the Sepolia testnet serves as a dry run for the mainnet, the implications of Glamsterdam are far-reaching for the broader Ethereum ecosystem. The upgrade is expected to improve the "timeliness" of block production, reducing the frequency of missed slots and improving the overall user experience by ensuring transactions are included in a more predictable and efficient manner.

For developers building on Layer 2 rollups or decentralized applications (dApps), the introduction of new stack-manipulation instructions and the increased maximum contract size offer new possibilities for complex logic. The addition of ETH transfer logs and a new slot-number opcode will provide more granular data for indexers and analytics tools, potentially reducing the computational overhead required to track network activity.

Security remains a primary focus of the upgrade process. The Ethereum Bug Bounty Program has been extended to include all specifications and EIPs related to Glamsterdam. This initiative encourages white-hat hackers to identify vulnerabilities in the protocol changes before they reach the mainnet. By fostering a culture of rigorous testing and public disclosure, the Ethereum community aims to mitigate the risks associated with such a comprehensive upgrade.

Looking Ahead

The name "Glamsterdam" itself is a nod to the culture of collaboration within the Ethereum developer community, combining "Gloas" (the consensus layer upgrade) with "Amsterdam" (the location of the 2022 Devconnect conference). This naming convention reflects the dual nature of the upgrade: a fusion of consensus-layer robustness and execution-layer agility.

As the industry watches the progress on the Sepolia testnet, the focus will soon shift toward the mainnet upgrade. While the specific date for the mainnet deployment has not been determined, the success of the Sepolia activation will serve as the primary indicator for the core developers to finalize the timeline. For the average ETH holder or user, the upgrade is expected to be seamless, requiring no direct action. However, for node operators, stakers, and smart contract developers, the next several months will be a period of preparation, testing, and coordination.

The Glamsterdam upgrade serves as a testament to the ongoing evolution of Ethereum. By consistently refining its protocol, Ethereum aims to maintain its position as a global settlement layer, capable of supporting the next generation of decentralized finance, digital identity, and beyond. As the network matures, the ability to implement deep architectural changes like ePBS and BALs demonstrates that the protocol is not just growing in capacity, but also in its ability to adapt to the technical demands of a global, high-frequency blockchain ecosystem.