Ethereum developers successfully activated the Glamsterdam upgrade on the Sepolia testnet on October 6, 2026, introducing a 200 million gas limit test to evaluate a threefold capacity increase. To prevent validators from defaulting to the old 60 million limit, Offchain Labs released an urgent Prysm client patch (v7.2.1) on October 5. The upgrade also tests enshrined proposer-builder separation (ePBS) and parallel processing features before developers schedule the subsequent Hoodi testnet phase and eventual mainnet release.
Prysm patch for gas limit
- ▪Without the Prysm version 7.2.1 update or manual configuration, validators would have proposed blocks at the previous 60 million gas limit, diluting the capacity test.
- ▪Offchain Labs published Prysm software version 7.2.1 on GitHub on October 5, 2026 at 21:18 UTC to address a configuration issue ahead of the Glamsterdam Sepolia testnet upgrade.
- ▪Prysm version 7.2.0, released on September 28, 2026, omitted the 200 million gas limit schedule because the upstream Sepolia configuration was published after the version was finalized.
Partial data columns
- ▪Operators can revert to full-column sharing in Prysm version 7.2.1 by using the `--disable-partial-data-columns` flag.
- ▪Prysm version 7.2.1 enables partial data columns by default, allowing nodes to share blob data at the level of individual cells rather than whole columns through PeerDAS.
Prysm builder settings
- ▪Prysm version 7.2.1 changes the format of the builder fields 'auth_data' and 'builder_pubkeys' to accept 0x-hex values instead of base64 to match the keymanager API.
- ▪Prysm version 7.2.1 adds validator client flags, including `--builder-urls` and `--builder-min-bid`, to configure builders for all validators from the command line.
Sepolia testnet activation
- ▪The Glamsterdam upgrade activated on the Sepolia testnet on October 6, 2026 at 13:53:36 UTC at epoch 353,024, slot 11,296,768.
- ▪Node operators were required to update both their execution and consensus clients to versions supporting Amsterdam and Gloas before the Sepolia fork.
Testing the gas limit increase
- ▪Prior to the Sepolia deployment, developers tested the 200 million gas limit on Glamsterdam Devnet 11 using approximately 84,000 validators across multiple clients.
- ▪The Glamsterdam upgrade on the Sepolia testnet raises the network's gas limit from approximately 60 million to 200 million gas per block.
Enshrined proposer-builder separation
- ▪Glamsterdam introduces enshrined proposer-builder separation (ePBS) via EIP-7732, moving the division of labor between block proposers and builders directly into Ethereum's consensus protocol.
- ▪Developers warned that malicious builders could exploit the Sepolia testnet by repeatedly winning block auctions and withholding execution payloads because test ether is inexpensive.
Future roadmap for Glamsterdam
- ▪Following the mainnet release of Glamsterdam, Ethereum development is planned to transition toward the Hegotá upgrade scheduled for 2027.
- ▪As of October 6, 2026, the Glamsterdam upgrade has not been scheduled for the Hoodi testnet, as Ethereum developers will analyze results from the Sepolia deployment first.
- ▪A final mainnet activation date for the Glamsterdam upgrade has not been confirmed by Ethereum developers.
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