With Fusaka in the rear-view, Ethereum 2026 upgrade comes into focus

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With Ethereum’s Fusaka upgrade in the rearview mirror, developers have turned their attention to future improvements codenamed Glamsterdam and Hegota.

Glamsterdam is expected sometime in 2026, and its headline features have been locked in for months.

Despite all the talk in 2025 about Ethereum developers’ renewed focus on scaling mainnet — making Ethereum itself more capable of quickly and affordably processing transactions at scale — Fusaka’s chief benefit was to reduce the cost of transactions on layer 2 blockchains, which are separate from, but settle on, Ethereum.

Glamsterdam, on the other hand, will reflect that renewed focus through its two major features: block-level access lists and enshrined proposer-builder separation, or ePBS.

Block-level access lists are expected to be particularly beneficial for complex applications, such as DeFi protocols.

At a high level, they’ll enable parallel processing of certain transactions on Ethereum.

This will allow for faster block validation, more predictable transaction fees, and, for certain transactions, dramatically lower fees.

Enshrined proposer-builder separation is also expected to lower the cost of using the chain and to increase throughput.

It could also increase the cost of censorship on Ethereum, according to one of its champions, the pseudonymous developer Potuz.

That said, a more significant anti-censorship feature considered for Glamsterdam has been delayed to the Hegota upgrade.

Hegota has yet to receive a target release date. We don’t even know what the upgrade will include — of the many Ethereum Improvement Proposals floating around online, only that anti-censorship feature has even been marked “considered for inclusion,” meaning it’s no guarantee.

That feature, fork-choice inclusion lists, or FOCIL, guarantees inclusion in a block of any valid transaction. It spurred intense debate among Ethereum developers this year.

“In an effort to shield the Ethereum validator set from centralising forces, the right to build blocks has been auctioned off to specialised entities known as builders,” FOCIL’s authors explained when proposing the feature in 2024.

But the builder market has become concentrated, spurring fears of a choke point that could be easily leveraged by governments and others seeking to censor transactions, the authors continued.

FOCIL addresses this by giving so-called validators — another, more distributed set of players in the Ethereum ecosystem — the power to require that builders include certain transactions.

Privacy Pools founder Ameen Soleimani has argued that the benefits of FOCIL are overstated, and it creates legal risks for US-based validators.

When Tornado Cash was placed on the US sanctions list, some 90% of validators declined to include transactions that touched Tornado Cash smart contracts, he said. As long as a single validator was willing to include those transactions, however, they would eventually settle on Ethereum.

Had US validators been forced to include those transactions, however, they could have faced the wrath of the US government, Soleimani argued.

Rollup developer Tim Clancy, who, like Soleimani, attended the New York trial of Tornado Cash developer Roman Storm in solidarity, called it the “single most important [proposal] for Ethereum.”

“It delivers a capability that Ethereum must have to continue delivering on its mission of being the most neutral blockspace,” he wrote on X earlier this year.

Of course, even if FOCIL makes its way into the Hegota upgrade, it won’t be the only major feature. Ethereum devs will begin debating which features should be included in Hegota on January 8. Headline features will likely be finalised by the end of February.

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Aleks Gilbert is DL News’ New York-based DeFi correspondent. You can reach him at [email protected].