# bal-devnet-2 spec :::info :mega: bal-devnet-2 targets to launch 04 Feb 2026. ([launched 2026-Feb-06 02:29:50 PM UTC](https://github.com/ethpandaops/bal-devnets/blob/master/network-configs/devnet-2/metadata/config.yaml#L27-L28)) ::: :::info ❗ EL clients: please add flags to enable/disable BAL optimizations batch/parallel io and parallel execution. ::: ## EIP List for bal-devnet-2 | Status | EIP | Title | Summary | PRs | |--------|-----|-------|---------|-----| | 🆙 | [EIP-7708](https://eips.ethereum.org/EIPS/eip-7708) | ETH transfers emit a log | All ETH transfers emit a log for unified tracking | [Respec topic & emitting addr + add LOG2 for SELFDESTRUCT @ self](https://github.com/ethereum/EIPs/pull/9003), [Clarify SELFDESTRUCT LOG2 events](https://github.com/ethereum/EIPs/pull/11127) | | 🆕 | [EIP-7778](https://eips.ethereum.org/EIPS/eip-7778) | Block Gas Accounting without Refunds | Exclude refunds from block gas accounting to prevent limit circumvention | | | 🆕 | [EIP-7843](https://eips.ethereum.org/EIPS/eip-7843) | SLOTNUM opcode | New opcode (0x4b) returning the current slot number | | | 🆙 | [EIP-7928](https://eips.ethereum.org/EIPS/eip-7928) | Block-Level Access Lists | Enforced block access lists enabling parallel validation and executionless state updates | [spurious entry detection](https://github.com/ethereum/EIPs/pull/10990), [gas validation](https://github.com/ethereum/EIPs/pull/11066), | | 🆙 | [EIP-8024](https://eips.ethereum.org/EIPS/eip-8024) | Backward compatible SWAPN, DUPN, EXCHANGE | New instructions for stack manipulation beyond the 16-item limit | included WITHOUT [Switch ecoding to push-postfix](https://github.com/ethereum/EIPs/pull/11094) | **Key:** - 🆙 EIP has updated! - 🆕 New EIP added. ### Implementation tracker EL ## Execution Layer Client Support | EIP | Geth | Besu | Reth | Nethermind | Erigon | Nimbus-EL | |-----|:----:|:----:|:----:|:----------:|:------:|:---------:| | 7928 (BAL) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | | 7708 (ETH Logs) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | | 7778 (Gas Refunds) | ✅ | ✅ | ✅ | ✅ | ❌ | ✅ | | 7843 (SLOTNUM) | ✅ | ✅ | ✅ | ✅ | ❌ | ✅ | | 8024 (SWAPN/DUPN) | ✅ | ✅ | ✅ | ✅ | ❌ | ✅ | ### Implementation tracker CL | Feature/EIP | Lodestar | Lighthouse | Prysm | | ----------- | -------- | ---------- | ----- | | **EIP-7928** | ✅ | ✅ | bal-devnet-1 | | **EIP-7843** | ✅ | ✅ | ❌ | ### Test Releases **Consensus Specs:** [`v1.6.1`](https://github.com/ethereum/consensus-specs/releases/tag/v1.6.1) :heavy_check_mark: Same as [bal-devnet-1](https://notes.ethereum.org/@ethpandaops/bal-devnet-1) **Execution Specs:** EEST Block-Level Access Lists (BAL) [v5.1.0](https://github.com/ethereum/execution-spec-tests/releases/tag/bal%40v5.1.0) :heavy_check_mark: :new: ### Spec versions required & Open PRs **EIP udpates included** - [EIP-7708 PR#9003 Respec topic & emitting addr](https://github.com/ethereum/EIPs/pull/9003) Merged :heavy_check_mark: - [EIP-7708 PR#11127 Clarify selfdestruct event](https://github.com/ethereum/EIPs/pull/11127) Merged :heavy_check_mark: - [EIP-7843 PR#11083 consistent naming, engine api](https://github.com/ethereum/EIPs/pull/11083) Merged :heavy_check_mark: - [EIP-7928 PR#10990 clarifications](https://github.com/ethereum/EIPs/pull/10990) Merged :heavy_check_mark:, [more clarifications](https://github.com/ethereum/EIPs/pull/11066) Merged :heavy_check_mark: - [EIP-7928 PR#10895 System contract access clarification](https://github.com/ethereum/EIPs/pull/10895) Merged :heavy_check_mark: - [EIP-7928 PR#10940 BAL retention period WSP](https://github.com/ethereum/EIPs/pull/10940) Merged :heavy_check_mark: - [EIP-7708 PR#11187 Clarify CALL to self does not emit transfer log](https://github.com/ethereum/EIPs/pull/11187) Merged :heavy_check_mark: :new: - [EIP-7708 PR#11190 clarify order of burn logs and coinbase transfer logs](https://github.com/ethereum/EIPs/pull/11190) Merged :heavy_check_mark: :new: - [EIP-7708 PR#11127 Clarify selfdestruct event](https://github.com/ethereum/EIPs/pull/11127) Merged :heavy_check_mark: :new: - [EIP-7778 PR#11191 Revert back to not having a receipt field](https://github.com/ethereum/EIPs/pull/11191) Merged :heavy_check_mark: :new: - [EIP-7778 PR#11138 clarify that user gas accounting remains unchanged](https://github.com/ethereum/EIPs/pull/11138) Merged :heavy_check_mark: :new: **Consensus Specs** Currently, No CL spec changes required. CLs need to implement [EIP-7843 PR #731 engine_forkchoiceUpdatedV4](https://github.com/ethereum/execution-apis/pull/731) **Execution Specs** - [EIP-7708 PR#2023 ETH Transfer Emit](https://github.com/ethereum/execution-specs/pull/2023) Merged :heavy_check_mark: - [EIP-7778 PR#1401 Block Gas Accounting](https://github.com/ethereum/execution-specs/pull/1401) Merged :heavy_check_mark: - [EIP-7843 PR#2007 SlotNum Opcode](https://github.com/ethereum/execution-specs/pull/2007) Merged :heavy_check_mark: - [EIP-7928 PR#1719 feat(specs,tests): Implement EIP-7928 Block-Level Access Lists](https://github.com/ethereum/execution-specs/pull/1719) with: [PR#1917 feat(specs): EIP-7928 move bal from payload](https://github.com/ethereum/execution-specs/pull/1917) Merged :heavy_check_mark: - [EIP-8024 PR#2021 feat(src): EIP-8024 tests added](https://github.com/ethereum/execution-specs/pull/2021) Merged :heavy_check_mark: **Execution APIs** [Amsterdam Engine API spec](https://github.com/ethereum/execution-apis/blob/main/src/engine/amsterdam.md) - [EIP-7843 PR #731 engine_forkchoiceUpdatedV4](https://github.com/ethereum/execution-apis/pull/731) Merged :heavy_check_mark: - [EIP-7928 PR #691: ExecutionPayloadV4](https://github.com/ethereum/execution-apis/pull/691) Merged :heavy_check_mark: - [EIP-7928 PR#726: Add EIP-7928 Block-level Access Lists JSON RPC methods](https://github.com/ethereum/execution-apis/pull/726) Open :exclamation: - [EIP-7928 PR#727 engine: define EIP-7928 API methods](https://github.com/ethereum/execution-apis/pull/727) Merged :heavy_check_mark: <!-- **devp2p** - [EIP-7928 GetBlockAccessLists, BlockAccessLists p2p](https://github.com/ethereum/devp2p/pull/264) Open :exclamation: --> **Other** - [bal-devnet-2 STEEL Milestone tracker](https://github.com/ethereum/execution-specs/milestone/32) :heavy_check_mark: - [EIP-7928 Issue#1938 Test vector metadata consideration](https://github.com/ethereum/execution-specs/issues/1938) Open :exclamation: ## 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 ``` /// 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, ``` ``` --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: ```yaml= participants: - cl_type: lighthouse cl_image: ethpandaops/lighthouse:bal-devnet-2 el_type: geth el_image: ethpandaops/geth:bal-devnet-2 el_extra_params: ["--history.state=0", "--gcmode=archive", "--syncmode=full"] count: 1 - cl_type: lodestar cl_image: ethpandaops/lodestar:bal-devnet-2 el_type: geth el_image: ethpandaops/geth:bal-devnet-2 el_extra_params: ["--history.state=0", "--gcmode=archive", "--syncmode=full"] count: 2 global_log_level: 'debug' network_params: genesis_delay: 20 fulu_fork_epoch: 0 gloas_fork_epoch: 1 seconds_per_slot: 6 snooper_enabled: true dora_params: image: ethpandaops/dora:eip7928-support ethereum_genesis_generator_params: image: ethpandaops/ethereum-genesis-generator:master additional_services: - dora port_publisher: additional_services: enabled: true public_port_start: 64400 ``` ## Metrics https://notes.ethereum.org/@ethpandaops/bal-otel