Ethereum Smart Contract: Comprehensive Updates to Fusaka and GlamAmsterdam

Ethereum Smart Contract: A major network upgrade

Ethereum Smart Contract has just undergone one of the largest infrastructure upgrades in network history. The Fusaka upgrade, which was activated on the Ethereum main network on December 3, 2025, changes the way smart contracts are executed, the carrying capacity of data blocks, and the way developers write and deploy code on the network. This article will explain what changes this upgrade has brought, why it is crucial to users building or using Ethereum smart contracts, and look forward to the next step in the Glamsterdam-and Hegota roadmaps.

Whether you are running verification nodes, deploying DeFi protocols, or just holding assets protected by Ethereum smart contracts, the changes included in this upgrade will cover the Gas economy, contract structure and the pace of future upgrades. The following sections will detail each item in turn, starting with the functionality actually delivered by Fusaka.

What changes have been brought about by the Fusaka upgrade?

According to developer-level analysis, Fusaka is the largest upgrade ever delivered by Ethereum, which is reflected in the number of Ethereum improvement proposals bundled. It integrates a total of twelve EIPs at the consensus layer and execution layer. Its core function is PeerDAS, or point-to-point data availability sampling, which allows verification nodes to verify Blob data without downloading all bytes themselves.

Specific to the Ethereum smart contract, Fusaka has increased the code size limit through EIP-7907 and added a CLZ opcode based on EIP-7939, providing developers with a more efficient way to perform certain mathematical operations and streamline bytecode. According to this version of the technical overview, this upgrade also introduces a block size cap and a Gas cap per transaction to prevent blocks that increase as throughput improves from crushing verification nodes. The client team has also improved memory and internal logic at the software level, changes that are invisible to everyday users, but they make nodes more resilient to operate as network activity grows.

Ethereum Smart Contract and EVM Object Format

For builders, one of the most far-reaching components of this update is the EVM object format, or EOF, which reconstructs the way Ethereum Smart Contract separates code and data. EOF no longer uses a single block of bytecode, but introduces separate sections of code, data, and metadata, which makes contracts easier to verify before running and reduces the possibility of some run-time errors slipping through.

In effect, this means that static analysis tools can check the structure of contracts before execution rather than just at runtime, and paves the way for faster JIT-style execution in future client-side implementations. Developers who deploy complex DeFi protocols, oracles, or account abstract wallets will get more predictable Gas costs and reduce the number of contracts that behave unexpectedly along the chain. Following Fusaka, there are two upgrades planned that involve only Blob parameters, designed to continuously expand Blob throughput without having to make a full hard fork every time.

Next step: The 2026 Glamsterdam and Hegota

client teams clearly see Fusaka as the cornerstone of the next phase of the Ethereum roadmap. The core of Glamsterdam is planned to be implemented in the first half of 2026 is to achieve embedded proposer-builder separation based on EIP-7732. This change aims to standardize the way blocks are built and reduce the risk of centralization in the process. Glamsterdam is currently in the test network and enhancement phase.

The second upgrade, tentatively named Hegota, is scheduled for later 2026, marking the Ethereum Foundation protocol team's shift to a faster and more frequent release pace rather than the previous model of major annual upgrades. Longer-term roadmap projects such as Verge, Purge and Srush continue to pursue lighter stateless clients, protocol simplification and account abstraction improvements. Anyone following the official schedule should check the relevant roadmap page directly, as the upgrade name and included EIPs may change while the proposal passes through the testnet. Developers currently developing based on Ethereum smart contracts should regard these names as directional guidelines rather than final solutions until each proposal is reviewed by the client team and logged on to the public test network.

Gas limits, security and developer impact

Larger blocks and higher Gas limits may sound like a completely positive impact on throughput, but they also increase the amount of data that the verification node must process per block. Fusaka's security measures, namely the block size cap under EIP-7934 and the transaction Gas cap under EIP-7825, are designed to prevent ultra-large blocks from becoming carriers of denial-of-service attacks while the network absorbs more activity. This balance between expansion and security is a recurring theme throughout the Ethereum roadmap.

For teams currently delivering Ethereum smart contracts, the actual checklist is as follows: retesting the Gas hypothesis against new opcodes and code size limits; monitoring Rollup fee behavior because Layer 2 benefits directly from the expanded Blob capacity; and focusing on official client release notes rather than relying on second-hand summaries. Contract addresses, balances and existing deployments are not affected by this upgrade; no migration is required for holders or most application developers. Active contract activity under the new format can be verified directly on the official chain browser.

Upgrade status

Core focuses: Fusaka (available on December 3, 2025)-PeerDAS, EOF basics, Gas and code size limits; Glamestead (testnet phase, target first half of 2026)-Embedded Proponder-Builder Separation (EIP-7732);Hegota (early discussion phase, second half of 2026)-Further Layer 1 enhancements and user experience-oriented improvements.

The above is the upgrade status of the Ethereum protocol. The information is integrated from the client team meeting minutes and the official roadmap, as of August 2026.

Impact on DeFi, Layer 2 and Auditing

The Rollup team is one of the biggest beneficiaries of this update. The expanded Blob capacity from PeerDAS means that the Layer 2 network can publish more transaction data to the Ethereum base layer at a lower cost per byte, which often means lower end-user fees on networks such as Arbitrum, Optimism and Base. Since most of the daily DeFi and NFT activity now takes place on these Rollups, the impact of upgrades is usually felt indirectly rather than through direct interaction with Ethereum smart contracts on one layer.

Auditors and security researchers also need to consider a new variable. The EVM object format changes the structure of bytecode, so static analysis tools and formal verification frameworks need to update support to fully parse contracts in EOF format. Teams auditing new blockchain deployments should confirm that their tool vendor has issued EOF compatibility notes before considering the audit complete, because old parsers built for older versions of bytecode may not recognize every issue in contracts compiled for the new format. The wallet infrastructure is also changing. EIP-7951 adds support for native secp256r1 curves, unlocks signature methods based on pass keys and hardware security modules for smart accounts, reducing the reliance on seed phrases for some wallet designs.

Expert Opinion

Protocol researchers following the Ethereum Core Developers Conference describe Fusaka as an infrastructure release rather than a user-facing release, with the goal of making subsequent upgrades more securely delivered. Analysts have characterized the EVM object formatting work in Fusaka as a groundbreaking work on which subsequent upgrades will build, rather than a completed feature. The client team's general expectation is that as the adoption of EOF in the tool ecosystem gradually expands over the next few release cycles, the deployment costs of Ethereum smart contracts will continue to decrease and the predictability of audits will continue to improve.