The Ethereum Foundation’s Protocol team has scheduled the Glamsterdam network upgrade on Sepolia for 6 October 2026 at 13:53:36 UTC.
The Glamsterdam testnet announcement, posted September 28, 2026, sets activation at epoch 353,024, slot 11,296,768 (UNIX timestamp 1791294816). That schedule is also reflected in the Sepolia update to EIP-7773. Hoodi and mainnet epochs are listed as TBD. The post states that this announcement covers Sepolia only and does not schedule a mainnet upgrade.
Sepolia node operators must update both their execution-layer and consensus-layer clients before that timestamp. A node that does not support the new rules cannot follow the upgraded testnet after activation.
What Glamsterdam Changes
Glamsterdam combines Amsterdam (execution) and Gloas (consensus). It follows the Fusaka upgrade and is framed as an L1 scaling step.
The two headline EIPs:
Enshrined proposer-builder separation (EIP-7732). A proposer includes a builder’s commitment to an execution payload. The builder later reveals that payload. The protocol handles payment to the proposer. A payload timeliness committee attests to whether the builder revealed the payload and whether the matching blob data was available on time. Consensus validation is separated from execution validation so validators have more time to check payloads.
Block-level access lists (EIP-7928). Each block carries an enforced list of accounts and storage locations accessed during the block, plus post-transaction state changes. Clients can then read state from disk in parallel, validate transactions in parallel, and compute state roots with less sequential work.
Gas accounting is also rewritten. EIP-8037 raises and separately meters the cost of creating state. EIP-8038 updates state-access costs. Other included changes cover intrinsic transaction gas, calldata, access lists, and block gas accounting without refunds.
The Foundation says contracts that rely on fixed gas stipends, hardcoded gas limits, or assumptions about remaining gas may break and should be tested against the new rules.
The Scheduled EIP List
EIP-7773 is the meta-EIP that tracks the fork. Scheduled inclusions named in the announcement include:
- EIP-2780, EIP-7688, EIP-7708, EIP-7732, EIP-7778
- EIP-7843, EIP-7928, EIP-7954, EIP-7976, EIP-7981
- EIP-7997, EIP-8024, EIP-8037, EIP-8038
- EIP-8045, EIP-8061, EIP-8246, EIP-8282
Supporting networking and informational EIPs listed alongside them include EIP-7975, EIP-8070, EIP-8136, EIP-8159, EIP-8189, EIP-7904, and EIP-8261.
Smaller developer-facing items in the same bundle: ETH transfer logs, a SLOTNUM opcode, a higher maximum contract size, a deterministic factory contract, and new stack-manipulation instructions. Consensus-side extras include excluding slashed validators from proposing and higher exit and consolidation churn.
The Ethereum Bug Bounty Program is open for Glamsterdam specifications. Client implementations become eligible once their versions are added to the announcement’s release tables.
Client Releases Named So Far
The Foundation’s table is incomplete. Blank rows remain for Grandine, Lighthouse, Nimbus (consensus), and Ethrex (execution). Operators are told to use only a release whose notes explicitly confirm Sepolia Glamsterdam support.
Consensus layer (Sepolia), as listed:
- Lodestar 1.49.0
- Prysm 7.2.0
- Teku 26.9.1
Validators must update both the beacon node and the validator client. Prysm 7.2.0 supports the Sepolia fork but defaults to a 60 million gas limit after activation. Operators who want to propose with a 200 million gas limit must set it through version-2 proposer settings or the keymanager API. The flag –suggested-gas-limit has no effect after Gloas, according to the Prysm 7.2.0 notes cited in the post.
Execution layer (Sepolia), as listed:
- Besu 26.9.0
- Erigon 3.7.0
- go-ethereum 1.17.6
- Nethermind 2.0.0
- Reth 2.7.0
Builder and validator tooling notes are still marked “to be added.”
Who Has to Do What
- Mainnet users and ETH holders: nothing. This is a Sepolia announcement.
- Non-staking Sepolia node operators: upgrade both clients before 13:53:36 UTC on 6 October.
- Sepolia stakers: same client upgrade, plus review ePBS duties and any builder-tooling changes.
- Hoodi or mainnet operators: no action from this post. Separate announcements will cover those networks.
- Application developers: review EIP-7773, test on Sepolia after the fork, and check gas estimation, logs, opcodes, and client interfaces.
The Crypto Times earlier covered Glamsterdam while the Q3 2026 window was still the public target, including the June scoping of EIP-7732 and EIP-7928 and a 200 million gas-limit floor discussed ahead of final testing. Monday’s post is the first Foundation schedule with a Sepolia epoch, slot, and UTC timestamp.
The name joins Gloas, a star name used for consensus upgrades, with Amsterdam, the Devconnect 2022 host city used for the execution-layer name.
Hoodi and Mainnet remain unscheduled. Client rows still empty in the official table will need versions before Sepolia operators can treat the 6 October fork as fully staffed.
