Ethereum’s Glamsterdam Upgrade Goes Live on Sepolia

Developers can now test applications and infrastructure against Ethereum’s Glamsterdam upgrade on Sepolia; ETH holders and mainnet users do not need to take action. The Ethereum Foundation scheduled the upgrade for Oct. 6 at 13:53:36 UTC, at epoch 353,024 and slot 11,296,768, and Cointelegraph reported that it went live at that time.

Sepolia gives teams a live test network to check compatibility before Ethereum sets a date for Glamsterdam on mainnet.

The Foundation’s Glamsterdam testnet announcement describes the upgrade as a combined change to Ethereum’s execution and consensus layers. Its headline features include enshrined proposer-builder separation (ePBS), which brings the division of block-building work into the protocol, and block-level access lists (BALs), which record accounts and storage locations used in a block. The changes are intended to support greater Layer 1 throughput; their effect on the live network remains to be tested.

What can teams test on Sepolia now?

Teams can deploy contracts and run applications, infrastructure and tooling against the new rules on the public testnet. The changes to block production and validation may affect client behavior, while gas-pricing changes may affect applications that estimate transaction costs or depend on particular gas assumptions. Testing against Sepolia gives developers a chance to identify compatibility issues before a mainnet rollout.

The upgrade also changes gas pricing to better reflect execution costs and state growth, according to the Foundation. That makes gas assumptions worth checking during testing, especially where software relies on fixed gas limits. Glamsterdam’s eventual mainnet effect will depend on the changes that proceed through testing and deployment; Sepolia activation by itself does not change how mainnet transactions work.

Do Sepolia operators need to update their clients?

Yes. Operators need compatible clients for both the execution layer and the consensus layer to follow Sepolia under Glamsterdam’s rules. The Foundation’s announcement listed client releases supporting the Sepolia activation and warned that a node without support for the new rules cannot follow the upgraded network.

For app developers and infrastructure providers, the immediate step is to test on Sepolia and review gas estimates, contract behavior and client compatibility. The upgrade is not live on mainnet: the Foundation said Hoodi and mainnet activation dates had not been decided. Mainnet users therefore have no Glamsterdam migration to make yet, and any later rollout will need its own schedule and client guidance.

Source material

• Glamsterdam testnet announcement — blog.ethereum.org