Ethereum developers, fresh off last month’s successful Fusaka upgrade that reduced node costs, are already moving full steam ahead in planning the blockchain’s next major 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 reside, 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 the Proposer-Builder Separation (ePBS), officially tracked as EIP-7732. The proposal would build into Ethereum’s core protocol a rule that separates nodes that build blocks from those that offer them, preventing a single actor from controlling which transactions are included or how they are ordered.
Today, this separation relies largely on off-chain services called relays, which introduce trust assumptions and centralization risks. Under ePBS, block builders would assemble blocks and cryptographically seal their contents, while nominators would simply choose the highest-yielding block without being able to see or tamper with what it contains. Transactions would only be revealed once the block is finalized, reducing opportunities for manipulation and abuse related to MEV, or maximum extractable value – the additional profits that validators or constructors can make by rearranging, 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. Rather than discovering this information on a transaction-by-transaction basis, Ethereum software – called clients – can preload and reuse data more efficiently, making block execution faster, more predictable, and easier to optimize. This change could help smooth gas costs and lay the foundation for future scaling improvements.
ePBS and block-level access lists are examples of Ethereum Improvement Proposals, or EIPs, which are formal proposals that describe changes to the protocol and serve as the primary coordination mechanism for the Ethereum development process.
The full scope of Glamsterdam has not yet been finalized, and additional EIPs are expected to be selected over the coming weeks. As for the timeline, the developers did not commit to a specific date, but indicated that the upgrade would likely take place in 2026.
Read more: Ethereum activates Fusaka upgrade, aiming to reduce node costs and speed up Layer 2 settlements
