Ethereum's Glamsterdam Upgrade Aims to Improve MEV Fairness

Ethereum developers, fresh off last month's successful Fusaka upgrade, are moving full-steam ahead on planning the blockchain's next major change, known as Glamsterdam. The name Glamsterdam 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 be undergoing 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 enshrined Proposer-Builder Separation, or ePBS, formally tracked as EIP-7732. This proposal aims to integrate into Ethereum's core protocol a rule that separates nodes who build blocks from those who propose them, preventing any single actor from controlling which transactions are included or how they are ordered.

Currently, this separation relies on off-chain services known as relays, which introduce trust assumptions and centralization risks. Under ePBS, block builders would assemble blocks and cryptographically seal their contents, while proposers would simply choose the highest-paying block without being able to see or tamper with its contents.

The transactions would only be revealed after the block is finalized, reducing opportunities for manipulation and abuse related to MEV, or maximal extractable value. Another proposal slated for Glamsterdam is Block-level Access Lists, or EIP-7928, which allows a block to declare in advance which accounts and smart-contract data it will access.

This change would enable Ethereum software known as clients to preload and reuse data more efficiently, enhancing block execution speed and predictability. Both ePBS and Block-level Access Lists are examples of Ethereum Improvement Proposals, which 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, with additional EIPs expected to be selected in the coming weeks. Developers have not committed to a specific date for the upgrade, but it is likely to take place sometime in 2026.