Glamsterdam Testnet Announcement
Posted by Protocol on September 28, 2026
Protocol Announcements
Glamsterdam follows the Fusaka upgrade, advancing Ethereum's L1 scaling roadmap with encrusted proposer-builder separation, block-level access lists, and changes to gas pricing that better reflect the cost of execution and state growth.
The Glamsterdam network upgrade is scheduled to activate on Sepolia at epoch 353,024, slot 11,296,768 (October 6, 2026, 13:53:36 UTC). See the activation table below for the deployment schedule. Sepolia-compatible client versions will be added to the client release tables as they are confirmed. Node operators must update both their execution and consensus layer clients before activation.
Glamsterdam Overview
Glamsterdam combines the Amsterdam execution layer upgrade with the Gloas consensus layer upgrade. Its headlining changes are encrusted proposer-builder separation (ePBS) and block-level access lists (BALs), which change how blocks are produced and validated to support greater L1 throughput.
Enshrined Proposer-Builder Separation
EIP-7732 brings the separation between block proposers and builders into Ethereum's consensus protocol. A proposer includes a builder's commitment to an execution payload, and the builder subsequently reveals that payload. The protocol handles payment to the proposer, reducing reliance on trusted middleware for the exchange between proposers and builders.
The change also separates consensus validation from execution validation, giving validators more time to validate execution payloads. A payload timeliness committee attests to whether the builder revealed its payload and the corresponding blob data was available on time. Validator operators and teams maintaining builder infrastructure should review the new duties and interfaces before the upgrade.
Block-Level Access Lists
EIP-7928 introduces enforced block-level access lists that record the accounts and storage locations accessed during a block, together with post-transaction state changes. These lists allow clients to read state from disk in parallel, validate transactions in parallel, and compute state roots more efficiently.
Together, ePBS and BALs provide a foundation for scaling execution capacity while keeping block validation practical for node operators.
Gas Pricing and State Growth
Glamsterdam adjusts gas accounting to better reflect resource usage. EIP-8037 increases and separately meters the cost of creating state, while EIP-8038 updates state-access costs. Additional changes cover intrinsic transaction gas, calldata, access lists, and block gas accounting.
Application developers should test contracts and gas estimation against the new rules. Contracts that rely on fixed gas stipends, hardcoded gas limits, or assumptions about remaining gas may need changes. See the Glamsterdam repricing impact guide for the affected-contracts search and testing guidance.
Developer and Validator Improvements
Glamsterdam also includes ETH transfer logs, a slot-number opcode, a higher maximum contract size, a deterministic factory contract, and new stack-manipulation instructions. Consensus changes include forward-compatible data structures, excluding slashed validators from proposing, and increased exit and consolidation churn.
The complete scheduled EIP list is below:
EIP-7773 tracks the Glamsterdam upgrade. The following EIPs are scheduled for inclusion:
- EIP-2780: Resource-based intrinsic transaction gas
- EIP-7688: Forward compatible consensus data structures
- EIP-7708: ETH transfers emit