ETH overhaul enters final development stage

TLDR

Ethereum developers have moved the Glamsterdam upgrade, its biggest protocol overhaul since the Merge, into the final development stage with closed devnet testing.

1. Glamsterdam is now running in private devnets with all planned EIPs, with mainnet activation targeted for the second half of 2026 but no exact date yet.
2. The upgrade introduces enshrined proposer-builder separation, block level access lists, and gas repricing that reshapes Ethereum's scaling and fee dynamics.
3. The key milestones from here are public testnets, client upgrades, and how Glamsterdam fits into Ethereum's broader 2026 roadmap and longer term ZK and security plans.

Deep Dive

1. Glamsterdam Reaches Final Development Phase

Multiple reports say Ethereum core teams have pushed the Glamsterdam hard fork into its final development stage, running closed devnets that include the full set of EIPs planned for the fork. These devnets are the last step before code hardening and public testnets, and there is still no fixed mainnet date, though the upgrade is expected in the second half of 2026 according to the initial Glamsterdam coverage.

Ethereum Foundation developer Parithosh Jayanthi is quoted as saying teams are testing devnets with "all the EIPs in them right now" and that there has been "massive progress", but timing still depends on how testing goes on both devnets and public testnets, as noted by follow up reporting.

2. Key Changes In The Overhaul

Glamsterdam centers on three big protocol changes. First is enshrined proposer-builder separation (ePBS, EIP 7732), which moves the block builder and proposer split into the protocol itself to reduce reliance on off chain MEV relays and mitigate centralization risk in block building.

Second, Block level Access Lists (BALs, EIP 7928) let each block pre declare which accounts and contract storage slots it will touch, enabling nodes to preload data and execute transactions in a more parallel and predictable way, improving Layer 1 throughput. Third, the fork reprices gas so compute becomes cheaper while state storage and access become more expensive, aligning fees closer to actual resource usage and nudging developers away from state heavy designs, as outlined in Glamsterdam focused analysis.

3. Roadmap, Timing, And Risks To Watch

Glamsterdam is one of two major 2026 forks, with Hegota scheduled later in the year for Verkle trees and further censorship resistance work, within a protocol roadmap that targets roughly two forks per year focused on scale, UX, and security, as summarized in the 2026 roadmap overview. Longer term, this sits inside a multi year path toward deeper ZK integration and post quantum security.

From here, the main checkpoints are: public testnet deployments, client diversity and readiness for ePBS, and community feedback on fee repricing and state costs. The biggest risks are slippage on timelines if bugs appear in devnets or testnets, and potential unintended effects on gas markets or validator economics that might require parameter tuning before or after mainnet activation.

Conclusion

Glamsterdam moving into its final development stage marks a concrete step in Ethereum's evolution from "just" a rollup hub toward a more scalable and MEV aware base layer. If testing converges smoothly, the upgrade could make Ethereum blocks more efficient and resilient, but the real impact will depend on how node operators, validators, and application developers adapt to its new fee structure and block building rules.