Glamsterdam hard fork

Amsterdam (execution) + Gloas (consensus) · Early 2027 (per Strawmap)

The roles of the builder who constructs the block and the validator who selects it are separated inside the protocol (ePBS), and the state a block will touch is declared in advance, opening the way to parallel execution (BAL).

What changes for you

Users
An ETH transfer sent from an existing account keeps the base gas of 21,000. However, a first-time transfer to a new address or a transaction that uses new storage becomes more expensive, because the cost of growing state goes up. Once wallets and RPCs are updated, the way you use them does not change. Every ETH transfer leaves a log like a token transfer, which also reduces the problem of exchanges failing to recognize deposits sent from smart contract wallets. It has not yet been applied, so the range of included EIPs may change.
Wallet & app developers
Gas estimation code needs adjusting. Logic that assumes a fixed base gas of 21,000 and eth_estimateGas handling must be updated to use the sum of execution gas and state gas, and if left as is, the gas may be underestimated and transactions can fail. In return, the maximum contract size rises from 24KiB to 64KiB, so large contracts no longer need to be split, and every ETH movement is logged, which makes it easier for contract wallets to track balances. The requirement that a CREATE2 factory exist at a fixed address also makes it easier to deploy to the same address on multiple chains.
Validators
Building a block and choosing it are separated inside the protocol (ePBS). The proposer picks a builder's bid and hands block construction to that builder. The proposer gains a new duty on the Payload Timeliness Committee (PTC), which checks that the execution payload arrived on time, while the verification burden before voting is reduced. Even if a builder submits an invalid execution payload, the attester does not miss its vote (attestation). The exit queue limit grows in proportion to total stake, which shortens the time to withdraw funds, and a consolidation-only limit is also introduced. Slashed validators are excluded from block proposals.
Node operators
Block access lists (BAL) become mandatory, so the accounts and storage a block touches are known in advance. Disk reads and transaction verification can be processed in parallel, which speeds up block validation, but in return each block adds the burden of propagating and storing a list averaging about 92.1KiB (compressed). On the consensus side, the weak subjectivity period shrinks from about 15.7 days to about 7.0 days. This is a large fork that changes both the beacon block structure and the Engine API, so both execution and consensus clients must be updated.

EIPs included

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