Overview
- Developers announced a tentative Sepolia public test on October 6 to rehearse Glamsterdam before any mainnet activation.
- Glamsterdam bundles enshrined proposer-builder separation (ePBS) and block-level access lists (BALs) to bake block production rules into the protocol and enable safer parallel execution.
- Private rehearsals cleared key milestones and Nethermind’s execution client completed 2,302 performance tests, processing 570.7 billion gas and demonstrating BALs in the test environment.
- Teams warned of a Sepolia-specific attack where fake builder identities could win block auctions with cheap test ether then withhold payloads, a disruption that could stall testing and must be mitigated.
- Client teams must publish Sepolia-ready software by September 29 to meet the compressed review window before the Oct. 6 test and developers still aim for a Q4 2026 mainnet target without a fixed activation date.