Ethereum developers, fresh off last month’s successful Fusaka upgrade, which reduced the cost of nodes, are already busy planning the blockchain’s next big change.
Enter “Glamsterdam”.
The name is a portmanteau of two simultaneous upgrades taking place on Ethereum’s two core layers. The execution layer, where transaction rules and smart contracts live, will undergo the Amsterdam upgrade, while the consensus layer, which coordinates validators and finalizes blocks, will see an upgrade known as Gloas.
At the heart of Glamsterdam is anchored the Proposer-Builder Separation (ePBS), formally tracked as EIP-7732. The proposal would bake into Ethereum’s core protocol a rule that separates nodes that build blocks from those that propose them, preventing a single actor from controlling which transactions are included or how they are ordered.
Today, this separation relies heavily on off-chain services, known as relays, which introduce trust assumptions and centralization risks. Under ePBS, block builders would collect blocks and cryptographically seal their contents, while proposers would simply choose the highest paying block without being able to see or tamper with what’s inside. The transactions will only be revealed after the block is completed, reducing the opportunities for manipulation and abuse related to MEV or maximum extractable value – the extra profit validators or builders can make by reordering, inserting or censoring transactions.
Another proposal planned for Glamsterdam is Block-level Access Lists (EIP-7928), an under-the-hood change that allows a block to declare in advance which accounts and smart contract data it will access. Instead of discovering this information transaction by transaction, Ethereum software—known as clients—can preload and reuse data more efficiently, making block execution faster, more predictable, and easier to optimize. The change could help smooth gas costs and lay an important foundation for future scaling improvements.
Both ePBS and block-level access lists are examples of Ethereum Improvement Proposals, or EIPs, which are formal proposals that outline changes to the protocol and serve as the main coordination mechanism for Ethereum’s development process.
The full scope of Glamsterdam has yet to be finalized and additional EIPs are expected to be selected over the coming weeks. As for timing, developers haven’t committed to a specific date, but have indicated that the upgrade will likely take place sometime in 2026.
Read more: Ethereum Enables Fusaka Upgrade, Aims to Reduce Node Costs, Speed Layer-2 Settlements
