glamsterdam-devnet-0 spec

# glamsterdam-devnet-0 spec :::info :mega: glamsterdam-devnet-0 targets to launch 15 April 2026. ::: :::info ❗ EL clients: **EIP-8037** will switch from hard coded **cost per state byte** to a variable cost based on the block gas limit. ::: ## EIP List for glamsterdam-devnet-0 | EIP | Title |Status |--------|-----|-------| |[EIP-7708](https://eips.ethereum.org/EIPS/eip-7708) | ETH transfers emit a log | |[EIP-7778](https://eips.ethereum.org/EIPS/eip-7778) | Block Gas Accounting without Refunds | |[EIP-7843](https://eips.ethereum.org/EIPS/eip-7843) | SLOTNUM opcode | |[EIP-7928](https://eips.ethereum.org/EIPS/eip-7928) | Block-Level Access Lists | :up: |[EIP-7954](https://eips.ethereum.org/EIPS/eip-7954) | Increase Maximum Contract Size | |[EIP-7975](https://eips.ethereum.org/EIPS/eip-7975) | eth/70 - partial block receipt lists | :new: |[EIP-8024](https://eips.ethereum.org/EIPS/eip-8024) | Backward compatible SWAPN, DUPN, EXCHANGE | |[EIP-8037](https://eips.ethereum.org/EIPS/eip-8037) | State Creation Gas Cost Increase | :up: |[EIP-8159](https://eips.ethereum.org/EIPS/eip-8159) | eth/71 - Block Access List Exchange | :new: |[EIP-7732](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-7732.md) | Enshrined Proposer-Builder Separation | :up: **Key:** - :up: EIP has updated! - :new: New EIP added. ### Implementation tracker EL ## Execution Layer Client Support Here you go: | EIP | Geth | Besu | Reth | Nethermind | Erigon | Nimbus-EL | Ethrex | |-----| :----:|:----:|:----:|:----------:|:------:|:---------:|:------:| | 7708 (ETH Logs) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | | 7778 (Gas Refunds) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | | 7843 (SLOTNUM) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | | 7928 (BAL) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | | 7954 (MContract) | ❌ | ❌ | ❌ | ❌ | ❌ | ✅ | ✅ | | 7975 (eth/70) | ✅ | :hammer: | ❌ | ✅ | ❌ | ❌ | ❌ | | 8024 (SWAPN/DUPN) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | | 8037 (stateIncr) | ✅ | ❌ | ❌ | ❌ | ❌ | ✅ | ✅ | | 8159 (eth/71) | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | | 7732 ePBS | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ### Implementation tracker CL | Feature/EIP | Lodestar | Lighthouse | Prysm | | ----------- | -------- | ---------- | ----- | | **EIP-7928** | ✅ | ✅ | bal-devnet-1 | | **EIP-7843** | ✅ | ✅ | ❌ | ### Test Releases **Consensus Specs:**  **Execution Specs:**  ### Spec versions required & Open PRs **EIP udpates included** 8037 > Top-level reservoir refund (ethereum/EIPs#11476): Currently, subcall revert/halt returns state gas to the parent's reservoir, but at depth 0 the sender still pays for state gas even when state changes are rolled back. The proposed change resets execution_state_gas_used to zero on top-level failure too, making behavior consistent at all call depths. Consensus is forming on the latter, but needs more discussion to isolate edge cases. https://github.com/ethereum/EIPs/pull/11468 or https://github.com/ethereum/EIPs/pull/11476 > 0 -> x -> 0 storage reservoir refill: When storage goes 0 -> x -> 0 in the same transaction, the net state growth is zero but state gas is not returned to the reservoir. @rakita proposes refilling the reservoir when storage returns to its original zero value, analogous to how EIP-3529 refunds regular gas for storage clearing. Same applies to SELFDESTRUCT of a locally created account (CREATE charges state gas, SELFDESTRUCT removes it, net zero). No EIP PR yet and needs more discussion. **Consensus Specs** Currently, No CL spec changes required. **Execution Specs** **Execution APIs** **Networking**  **Other** ## Client BAL features | EL Client | Exec Par. | Batch IO (required) | State Par. | |-------------|:---------:|:--------:|:----------:| | Geth | ✅ | ✅ | ✅ | | Nethermind | ❓ | ❓ | ✅ | | Erigon | ✅ | ❓ | ❓ | | Besu | ✅ | ✅ | ✅ | | Reth | ✅ | ✅ | ✅ | These flags allow us to enable / disable devnet-2 features. Especially BAL related features. ## Feature flags ### Besu | Option | Default | Type | Description | |------------------------------------------------|---------|---------|------------------------------------------------------------------------------------------------------------------------| | `--Xbal-optimization-enabled` | `true` | boolean | Allows disabling BAL-based optimizations. | | `--Xbal-perfect-parallelization-enabled` | `true` | boolean | Allows disabling BAL-based perfect parallelization even when BALs are present. | | `--Xbal-lenient-on-state-root-mismatch` | `true` | boolean | Log an error instead of throwing when the BAL-computed state root does not match the synchronously computed root. | | `--Xbal-trust-state-root` | `false` | boolean | Trust the BAL-computed state root without verification. | | `--Xbal-log-bals-on-mismatch` | `false` | boolean | Log the constructed block’s BAL when they differ. | | `--Xbal-api-enabled` | `false` | Boolean | Enable `eth_getBlockAccessListByBlockNumber` and `eth_getBlockAccessListByBlockHash` methods and BALs in simulation. | | `--Xbal-state-root-timeout` | `1000` | long | Timeout in ms when waiting for the BAL-computed state root. | | `--Xbal-processing-timeout` | `1000` | long | Timeout in ms when waiting for BAL transaction processing results. | | `--Xbal-prefetch-reading-enabled` | `false` | boolean | Enable prefetching of state data based on BAL read operations. | | `--Xbal-prefetch-sorting-enabled` | `true` | boolean | Enable sorting optimization during BAL prefetch operations. | ### Reth ```rust /// Whether to disable BAL (Block Access List, EIP-7928) based parallel execution. /// When disabled, falls back to transaction-based prewarming even when a BAL is available. disable_bal_parallel_execution: bool, /// Whether to disable BAL-driven parallel state root computation. /// When disabled, the BAL hashed post state is not sent to the multiproof task for /// early parallel state root computation. disable_bal_parallel_state_root: bool, /// Whether to disable BAL (Block Access List) batched IO during prewarming. /// When disabled, falls back to individual per-slot storage reads instead of /// batched cursor reads via `storage_range`. disable_bal_batch_io: bool Flags: --engine.disable-bal-parallel-execution Disable BAL (Block Access List, EIP-7928) based parallel execution. When set, falls back to transaction-based prewarming even when a BAL is available --engine.disable-bal-parallel-state-root Disable BAL-driven parallel state root computation. When set, the BAL hashed post state is not sent to the multiproof task for early parallel state root computation --engine.disable-bal-batch-io Disable BAL (Block Access List) batched IO during prewarming. When set, falls back to individual per-slot storage reads instead of batched cursor reads ``` ### Nethermind WIP ### Geth Possible values full, sequential, nobatchio. `--bal.executionmode=nobatchio` ### Erigon WIP IGNORE_BAL (see https://github.com/erigontech/erigon/pull/19903) --- ## Local testing Kurtosis example: ## Metrics https://notes.ethereum.org/@ethpandaops/bal-otel Previous devnet spec sheet for reference: https://notes.ethereum.org/@ethpandaops/bal-devnet-2