Glamsterdam brings relay-free blocks to Sepolia on October 6

The Ethereum Foundation's Glamsterdam network upgrade activates on Sepolia at epoch 353,024 — slot 11,296,768 — on October 6. Research contributor Alex Stokes highlighted the upgrade's headline feature: blocks built without trusted relays, delivered via enshrined proposer-builder separation (ePBS). Following Fusaka, Glamsterdam also adds block-level access lists and gas pricing changes that better reflect execution and state-growth costs.

• Client teams are shipping fork support ahead of the testnet: Geth v1.17.6 schedules Amsterdam on Sepolia at timestamp 1791294816 (October 6) and tells Sepolia node operators to upgrade beforehand, while the EF's Platåberget testnet serves as an early public testing ground for the combined Gloas and Amsterdam upgrades.
• Breaking change for app developers: any tool relying on a hardcapped maximum gas limit — wallets, indexers, gas estimators — must be updated, since repricing removes the fixed gas ceiling.

Sepolia activation remains the near-term milestone ahead of mainnet.