Forward compatible consensus data structures (EIP-7688) - #4630
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EIP-4788 exposed the beacon root to smart contracts, but smart contracts need to be redeployed / upgraded whenever generalized indices change during a fork, even if that fork does not touch any used functionality. That is analogous to an OS without ABI stability, requiring programs to be maintained and re-compiled due to random breakages in OS updates. This issue expands further to bridges on other blockchains, and also into wallets / dApps that verify data from the beacon chain instead. Such projects do not typically share Ethereum's release cadence. - https://eips.ethereum.org/EIPS/eip-4788 EIP-7688 introduces forward compatibility for beacon chain structures. Generalized indices remain same when list capacities evolve over forks, containers no longer get re-indexed when reaching a new power-of-2 number of fields, and fields can be deprecated, leaving a gap in the Merkle tree instead of triggering re-indexing. - https://eips.ethereum.org/EIPS/eip-7688 EIP-7688 was requested for inclusion by popular projects: - For Electra by Rocketpool: https://xcancel.com/KaneWallmann/status/1816729724145795258 - For Fulu by Lido: ethereum/pm#1356 (comment)
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* Forward compatible consensus data structures (EIP-7688) - EIP https://eips.ethereum.org/EIPS/eip-7688 - Spec ethereum/consensus-specs#4630 - Tests ethereum/consensus-specs#4630 (comment) - Kurtosis ethereum/consensus-specs#4630 (comment) * ForkedAggregate cleanup * Sync gossip checks * Cleanups * Resttest * Focil test * Progressive for PayloadAttestation, ExecutionPayloadBid, Envelope * Use mapIt * Heze constants * use v1.7.0-alpha.12 consensus reference tests (#8729) * use v1.7.0-alpha.12 consensus reference tests * Reduce `MAX_BUILDER_DEPOSIT_REQUESTS_PER_PAYLOAD` to 64 - ethereum/consensus-specs#5420 * Remove `MAX_DEPOSIT_REQUESTS_PER_PAYLOAD` in Gloas - ethereum/consensus-specs#5436 * Add the IL bitlist to bid - ethereum/consensus-specs#5410 * Fix some inconsistencies in fulu partial-columns spec - ethereum/consensus-specs#5357 * Restrict builder deposits to payload builders - ethereum/consensus-specs#5439 * Only reset builder withdrawal epoch if its balance has been swept - ethereum/consensus-specs#5384 * Set `BUILDER_WITHDRAWAL_PREFIX` to 0xB0 - ethereum/consensus-specs#5416 * Reduce `MIN_BUILDER_WITHDRAWABILITY_DELAY` to 64 epochs - ethereum/consensus-specs#5426 * Re-generate test reports * Fix test_light_client_processor * Fix block_sim * Drop duplicate import * Fix resttest
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**Motivation** - https://eips.ethereum.org/EIPS/eip-7688 **Description** - implement ethereum/consensus-specs#4630 **AI Assistance Disclosure** - codex assistance --------- Co-authored-by: NC <17676176+ensi321@users.noreply.github.com> Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com> Co-authored-by: twoeths <10568965+twoeths@users.noreply.github.com> Co-authored-by: Tuyen Nguyen <twoeths@users.noreply.github.com>
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## Relevant Links - https://eips.ethereum.org/EIPS/eip-7688 - ethereum/consensus-specs#4630 ## Proposed Changes Adds the necessary types and components to support EIP-7688, along with the cargo patches to pull in the `progressive` versions of the crates in our SSZ stack. ## Testing ```yaml participants_matrix: el: - el_type: nethermind el_image: ethpandaops/nethermind:master cl: - cl_type: nimbus cl_image: ethpandaops/nimbus-eth2:glamsterdam-devnet-7-minimal - cl_type: lodestar cl_image: ethpandaops/lodestar:glamsterdam-devnet-7 - cl_type: lighthouse cl_image: ethpandaops/lighthouse:glamsterdam-devnet-7 - cl_type: teku cl_image: ethpandaops/teku:glamsterdam-devnet-7 ethereum_genesis_generator_params: image: "ethpandaops/ethereum-genesis-generator:glamsterdam-devnet-7" dora_params: image: ethpandaops/dora:glamsterdam-devnet-7 global_log_level: debug network_params: preset: minimal gloas_fork_epoch: 1 additional_services: - dora ``` ## Additional Info Based on the original work by @michaelsproul in #8505 Co-authored-by: Michael Sproul <michael@sigmaprime.io>
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EIP-4788 exposed the beacon root to smart contracts, but smart contracts need to be redeployed / upgraded whenever generalized indices change during a fork, even if that fork does not touch any used functionality. That is analogous to an OS without ABI stability, requiring programs to be maintained and re-compiled due to random breakages in OS updates.
This issue expands further to bridges on other blockchains, and also into wallets / dApps that verify data from the beacon chain instead. Such projects do not typically share Ethereum's release cadence.
EIP-7688 introduces forward compatibility for beacon chain structures. Generalized indices remain same when list capacities evolve over forks, containers no longer get re-indexed when reaching a new power-of-2 number of fields, and fields can be deprecated, leaving a gap in the Merkle tree instead of triggering re-indexing.
EIP-7688 was requested for inclusion by popular projects: