Ethereum's next major hard fork, Glamsterdam, has entered advanced devnet testing with a tentative mainnet target of Q3 2026. The upgrade centers on two protocol-level changes: Enshrined Proposer-Builder Separation (ePBS, EIP-7732) and Block-Level Access Lists (BALs, EIP-7928). Together with a bu...
Ethereum's next major hard fork, Glamsterdam, has entered advanced devnet testing with a tentative mainnet target of Q3 2026. The upgrade centers on two protocol-level changes: Enshrined Proposer-Builder Separation (ePBS, EIP-7732) and Block-Level Access Lists (BALs, EIP-7928). Together with a bundled gas repricing package (EIP-8007), developers project a 78% reduction in Layer 1 gas fees and a path toward 10,000 transactions per second — up from approximately 30 TPS today.
The stakes are structural, not cosmetic. Currently, 80–90% of Ethereum blocks are produced through external relay infrastructure, with seven relay operators controlling 99% of MEV-Boost traffic. Glamsterdam replaces this off-chain trust layer with an in-protocol commit-reveal mechanism. It is the most substantial architectural change to Ethereum's block production pipeline since the Merge in September 2022.
As of the April 2026 Ethereum Foundation checkpoint, the generalized Glamsterdam devnet is live but the original H1 2026 target appears unlikely. Core developers have acknowledged that ePBS implementation "touches practically everything" in the client stack, and the realistic mainnet window has shifted to Q3 2026 at the earliest.
Ethereum's current block production relies on MEV-Boost, a sidecar software maintained by Flashbots that mediates between validators (proposers) and block builders. According to relay data from relayscan.io, MEV-Boost processes approximately 92% of all Ethereum blocks. The relay landscape is concentrated: relay.ultrasound.money handles 33.9% of payloads, titanrelay.xyz captures 24.2%, and bloxroute.max-profit takes 14.7%.
This concentration creates a trust dependency. Proposers must trust relays to faithfully pass builder bids without tampering. Builders must trust that proposers will not unbundle their blocks. Neither guarantee is enforced at the protocol level. If a relay goes offline or acts maliciously, the downstream effects propagate to block production itself.
Cumulative MEV extracted across Ethereum surpassed $1.8 billion by mid-2025, according to Flashbots data, with $40–60 million captured monthly through arbitrage and sandwich strategies. The top two builders capture over 90% of block auctions, with beaverbuild.org, Titan Builder, and rsync-builder dominating the market. This degree of concentration in off-chain infrastructure is the central problem Glamsterdam aims to address.
Glamsterdam bundles three categories of protocol changes into a single hard fork:
| Component | EIP | Function | |-----------|-----|----------| | Enshrined PBS | EIP-7732 | Moves proposer-builder separation into the consensus protocol | | Block-Level Access Lists | EIP-7928 | Enables parallel transaction execution via pre-declared state access | | Gas Repricing | EIP-8007 (bundle) | Realigns opcode costs with actual hardware benchmarks | | Contract Size Increase | EIP-7954 | Raises maximum contract size limit |
Vitalik Buterin outlined the full scope in a February 2026 post detailing eight EIPs. The Ethereum Foundation subsequently classified EIP-7732 and EIP-7928 as "headliner" proposals, receiving top development priority. FOCIL (EIP-7805), which was initially considered for inclusion, has been deferred to the subsequent Hegotá upgrade after the Base engineering team warned that bundling it with ePBS could push the fork beyond 2026 entirely.
EIP-7732 formally separates the proposer role (selecting the consensus block) from the builder role (assembling the execution payload) at the protocol level. Today, this separation exists informally through MEV-Boost. After Glamsterdam, the handoff is enshrined in consensus with explicit deadlines, payload commitments, and fallback behavior.
The mechanism works as follows: builders submit sealed bids to proposers on-chain. The proposer selects the highest bid and commits to it via the beacon chain. The builder then reveals the full execution payload within a defined time window. If the builder fails to deliver, the protocol handles the non-delivery without halting chain liveness — a guarantee that current relay infrastructure cannot make.
The practical effect is the elimination of relay trust assumptions. Independent relays currently operate as public goods with unclear funding models. Their sustainability, as noted by multiple researchers, depends on altruism or verticalized business models. ePBS removes the need for relays entirely by encoding their function into the consensus layer.
For MEV specifically, researchers estimate that enshrining builder-proposer separation could reduce extractable value by up to 70% by standardizing auction rules and removing opportunities for relay-level manipulation. However, Buterin has acknowledged that ePBS alone does not solve block builder centralization — it only prevents builder centralization from translating into staking centralization. Further measures, including FOCIL and encrypted mempools, are planned for subsequent upgrades.
EIP-7928 introduces Block-Level Access Lists (BALs), which record all accounts and storage locations accessed during block execution, along with their post-execution values. This metadata enables a fundamental shift in how nodes validate blocks.
Currently, Ethereum executes transactions sequentially within each block. A node must process transaction 1 before transaction 2, because transaction 2 might depend on state changes made by transaction 1. BALs make these dependencies explicit. If two transactions access entirely different storage slots, nodes can validate them in parallel.
Analysis of historical Ethereum block data shows that 60–80% of transactions access disjoint storage slots, meaning they have no state dependencies and can be fully parallelized. The remaining 20–40% can be partially parallelized using post-transaction state diffs included in the BAL.
The overhead is modest: approximately 35 KiB per block at the current 36 million gas limit, with an average BAL size of roughly 70 KiB. When combined with the gas limit increase to 200 million, BALs enable parallel disk reads, parallel transaction validation, and parallel state root computation — cutting worst-case block validation latency and directly increasing throughput capacity.
Glamsterdam includes EIP-8007, a bundled gas repricing package that realigns opcode costs with actual hardware execution benchmarks. Current gas costs for many operations were set years ago and no longer reflect the true computational expense of those operations on modern hardware.
The repricing, combined with a phased gas limit increase, projects a 78% reduction in Layer 1 execution costs. The gas limit will rise from the current 60 million to 100 million initially, then to 200 million once ePBS is fully operational. Over 100 core developers reached consensus on the 200 million minimum at a late-April 2026 working session.
For context, average Ethereum L1 transaction fees in April 2026 were already at historic lows: approximately $0.16–$0.22 per transaction, down from $1.85 in mid-2025 following the December 2025 Fusaka upgrade. Glamsterdam would push these costs further toward the $0.03–$0.05 range for simple transfers, narrowing the cost gap with Layer 2 networks (currently $0.001–$0.05 per transaction) and with competing Layer 1 chains.
The throughput target of 10,000 TPS represents a 300x increase from Ethereum's current ~30 TPS. This figure assumes full parallel execution under BALs and the 200 million gas limit. Developers have been cautious about framing this as a guarantee, noting that real-world throughput depends on transaction composition and state access patterns.
The Ethereum Foundation's Checkpoint #9, published April 10, 2026, provides the most authoritative status update. Key findings:
The primary delay risk is ePBS implementation complexity. The protocol must handle disagreement between two parties (proposer and builder) in consensus — a fundamentally new coordination problem at the consensus layer. Non-headliner features like gas repricing add additional testing surface.
Validator Economics: Approximately 35.8 million ETH (~30% of circulating supply) is currently staked across 1.1 million active validators, earning an average yield of 3.3% annually. ePBS changes the revenue structure for validators by formalizing the builder auction. Validators will receive builder payments directly through the protocol rather than through relay-mediated channels, potentially reducing the information asymmetry that currently favors sophisticated MEV searchers.
Relay Operators and Flashbots: Flashbots anticipated the ePBS transition by migrating to BuilderNet in December 2024 — a decentralized building network jointly operated with BeaverBuild and Nethermind. Glamsterdam makes BuilderNet's decentralized approach the default for all participants. Traditional relay operators face obsolescence.
Layer 2 Positioning: Layer 2 networks currently handle approximately 95% of Ethereum's transaction throughput. A 78% L1 fee reduction and 10,000 TPS capacity narrows the L1/L2 cost differential, potentially shifting some transaction volume back to mainnet. However, L2 fees at $0.001–$0.05 still maintain a meaningful cost advantage for high-frequency, low-value transactions.
ETH Price Response: ETH gained 9.2% on April 14, 2026, the day after devnet milestone announcements, briefly breaking a bearish channel that had held since August 2025. ETH remains 58% below its 2025 all-time high, with the token trading near $1,800–$2,000 in early May. Analysts at Citi target $3,175, while Standard Chartered forecasts $7,500 — a spread that reflects deep uncertainty about whether protocol improvements will translate into token value accrual.
Glamsterdam is not a performance upgrade. It is an infrastructure replacement. The fork rewrites how Ethereum builds blocks, validates state, and prices computation — three pillars that determine the network's security model, economic structure, and competitive position.
The core tension is between ambition and complexity. ePBS touches every layer of the client stack and introduces a novel two-party coordination problem at the consensus level. The devnet is stable but the path to mainnet requires dual audits, public testnet validation, and cross-client compatibility across an increasingly diverse execution client ecosystem.
For the broader market, the implications are practical: if Glamsterdam ships as specified, Ethereum's Layer 1 becomes viable for a class of transactions currently relegated to Layer 2s or competing chains. Whether that translates into fee revenue, token demand, or validator economics remains an open question — one that the data will answer only after the fork activates.