# Electra -- The Beacon Chain - [Introduction](#introduction) - [Types](#types) - [Modified `AggregationBits`](#modified-aggregationbits) - [Modified `Attestations`](#modified-attestations) - [Modified `AttesterSlashings`](#modified-attesterslashings) - [Modified `AttestingIndices`](#modified-attestingindices) - [New `CommitteeBits`](#new-committeebits) - [New `ConsolidationRequests`](#new-consolidationrequests) - [New `DepositRequests`](#new-depositrequests) - [New `PendingConsolidations`](#new-pendingconsolidations) - [New `PendingDeposits`](#new-pendingdeposits) - [New `PendingPartialWithdrawals`](#new-pendingpartialwithdrawals) - [New `WithdrawalRequests`](#new-withdrawalrequests) - [Constants](#constants) - [Misc](#misc) - [Withdrawal prefixes](#withdrawal-prefixes) - [Execution-layer triggered requests](#execution-layer-triggered-requests) - [Presets](#presets) - [Gwei values](#gwei-values) - [Rewards and penalties](#rewards-and-penalties) - [State list lengths](#state-list-lengths) - [Max operations per block](#max-operations-per-block) - [Execution](#execution) - [Withdrawals processing](#withdrawals-processing) - [Pending deposits processing](#pending-deposits-processing) - [Configs](#configs) - [Execution](#execution-1) - [Validator cycle](#validator-cycle) - [Containers](#containers) - [New containers](#new-containers) - [`PendingDeposit`](#pendingdeposit) - [`PendingPartialWithdrawal`](#pendingpartialwithdrawal) - [`PendingConsolidation`](#pendingconsolidation) - [`DepositRequest`](#depositrequest) - [`WithdrawalRequest`](#withdrawalrequest) - [`ConsolidationRequest`](#consolidationrequest) - [`ExecutionRequests`](#executionrequests) - [`SingleAttestation`](#singleattestation) - [Modified containers](#modified-containers) - [`AttesterSlashing`](#attesterslashing) - [`BeaconBlockBody`](#beaconblockbody) - [`Attestation`](#attestation) - [`IndexedAttestation`](#indexedattestation) - [`BeaconState`](#beaconstate) - [`NewPayloadRequest`](#newpayloadrequest) - [Dataclasses](#dataclasses) - [Modified dataclasses](#modified-dataclasses) - [`ExpectedWithdrawals`](#expectedwithdrawals) - [Helpers](#helpers) - [Predicates](#predicates) - [Modified `compute_proposer_index`](#modified-compute_proposer_index) - [Modified `is_eligible_for_activation_queue`](#modified-is_eligible_for_activation_queue) - [New `is_compounding_withdrawal_credential`](#new-is_compounding_withdrawal_credential) - [New `has_compounding_withdrawal_credential`](#new-has_compounding_withdrawal_credential) - [New `has_execution_withdrawal_credential`](#new-has_execution_withdrawal_credential) - [Modified `is_fully_withdrawable_validator`](#modified-is_fully_withdrawable_validator) - [Modified `is_partially_withdrawable_validator`](#modified-is_partially_withdrawable_validator) - [New `is_eligible_for_partial_withdrawals`](#new-is_eligible_for_partial_withdrawals) - [Misc](#misc-1) - [New `get_committee_indices`](#new-get_committee_indices) - [New `get_max_effective_balance`](#new-get_max_effective_balance) - [Beacon state accessors](#beacon-state-accessors) - [New `get_balance_churn_limit`](#new-get_balance_churn_limit) - [New `get_activation_exit_churn_limit`](#new-get_activation_exit_churn_limit) - [New `get_consolidation_churn_limit`](#new-get_consolidation_churn_limit) - [New `get_pending_balance_to_withdraw`](#new-get_pending_balance_to_withdraw) - [Modified `get_attesting_indices`](#modified-get_attesting_indices) - [Modified `get_next_sync_committee_indices`](#modified-get_next_sync_committee_indices) - [Beacon state mutators](#beacon-state-mutators) - [Modified `initiate_validator_exit`](#modified-initiate_validator_exit) - [New `switch_to_compounding_validator`](#new-switch_to_compounding_validator) - [New `queue_excess_active_balance`](#new-queue_excess_active_balance) - [New `compute_exit_epoch_and_update_churn`](#new-compute_exit_epoch_and_update_churn) - [New `compute_consolidation_epoch_and_update_churn`](#new-compute_consolidation_epoch_and_update_churn) - [Modified `slash_validator`](#modified-slash_validator) - [Beacon chain state transition function](#beacon-chain-state-transition-function) - [Epoch processing](#epoch-processing) - [Modified `process_epoch`](#modified-process_epoch) - [Modified `process_registry_updates`](#modified-process_registry_updates) - [Modified `process_slashings`](#modified-process_slashings) - [New `apply_pending_deposit`](#new-apply_pending_deposit) - [New `process_pending_deposits`](#new-process_pending_deposits) - [New `process_pending_consolidations`](#new-process_pending_consolidations) - [Modified `process_effective_balance_updates`](#modified-process_effective_balance_updates) - [Execution engine](#execution-engine) - [Engine APIs](#engine-apis) - [Modified `is_valid_block_hash`](#modified-is_valid_block_hash) - [Modified `notify_new_payload`](#modified-notify_new_payload) - [Modified `verify_and_notify_new_payload`](#modified-verify_and_notify_new_payload) - [Block processing](#block-processing) - [Withdrawals](#withdrawals) - [New `get_pending_partial_withdrawals`](#new-get_pending_partial_withdrawals) - [Modified `get_validators_sweep_withdrawals`](#modified-get_validators_sweep_withdrawals) - [Modified `get_expected_withdrawals`](#modified-get_expected_withdrawals) - [New `update_pending_partial_withdrawals`](#new-update_pending_partial_withdrawals) - [Modified `process_withdrawals`](#modified-process_withdrawals) - [Execution payload](#execution-payload) - [New `get_execution_requests_list`](#new-get_execution_requests_list) - [Modified `process_execution_payload`](#modified-process_execution_payload) - [Operations](#operations) - [Modified `process_operations`](#modified-process_operations) - [Attestations](#attestations) - [Modified `process_attestation`](#modified-process_attestation) - [Deposits](#deposits) - [Modified `get_validator_from_deposit`](#modified-get_validator_from_deposit) - [Modified `add_validator_to_registry`](#modified-add_validator_to_registry) - [Modified `apply_deposit`](#modified-apply_deposit) - [New `is_valid_deposit_signature`](#new-is_valid_deposit_signature) - [Modified `process_deposit`](#modified-process_deposit) - [Voluntary exits](#voluntary-exits) - [Modified `process_voluntary_exit`](#modified-process_voluntary_exit) - [Execution-layer withdrawal requests](#execution-layer-withdrawal-requests) - [New `process_withdrawal_request`](#new-process_withdrawal_request) - [Deposit requests](#deposit-requests) - [New `process_deposit_request`](#new-process_deposit_request) - [Execution-layer consolidation requests](#execution-layer-consolidation-requests) - [New `is_valid_switch_to_compounding_request`](#new-is_valid_switch_to_compounding_request) - [New `process_consolidation_request`](#new-process_consolidation_request) ## Introduction Electra is a consensus-layer upgrade containing a number of features. Including: - [EIP-6110](https://eips.ethereum.org/EIPS/eip-6110): Supply validator deposits on chain - [EIP-7002](https://eips.ethereum.org/EIPS/eip-7002): Execution layer triggerable exits - [EIP-7251](https://eips.ethereum.org/EIPS/eip-7251): Increase the MAX_EFFECTIVE_BALANCE - [EIP-7549](https://eips.ethereum.org/EIPS/eip-7549): Move committee index outside Attestation - [EIP-7691](https://eips.ethereum.org/EIPS/eip-7691): Blob throughput increase ## Types ### Modified `AggregationBits` ```python # [Modified in Electra:EIP7549] class AggregationBits(BitList): """ The participation bits of all committees participating in an attestation, concatenated in committee order. """ LIMIT = MAX_VALIDATORS_PER_COMMITTEE * MAX_COMMITTEES_PER_SLOT ``` ### Modified `Attestations` ```python # [Modified in Electra:EIP7549] class Attestations(List[Attestation]): """ The attestations included in a beacon block. """ LIMIT = MAX_ATTESTATIONS_ELECTRA ``` ### Modified `AttesterSlashings` ```python # [Modified in Electra:EIP7549] class AttesterSlashings(List[AttesterSlashing]): """ The attester slashings included in a beacon block. """ LIMIT = MAX_ATTESTER_SLASHINGS_ELECTRA ``` ### Modified `AttestingIndices` ```python # [Modified in Electra:EIP7549] class AttestingIndices(List[ValidatorIndex]): """ The indices of the validators participating in an attestation. """ LIMIT = MAX_VALIDATORS_PER_COMMITTEE * MAX_COMMITTEES_PER_SLOT ``` ### New `CommitteeBits` ```python class CommitteeBits(BitVector): """ Bits marking which committees of a slot participate in an attestation. """ LENGTH = MAX_COMMITTEES_PER_SLOT ``` ### New `ConsolidationRequests` ```python class ConsolidationRequests(List[ConsolidationRequest]): """ The consolidation requests pertaining to a single execution payload. """ LIMIT = MAX_CONSOLIDATION_REQUESTS_PER_PAYLOAD ``` ### New `DepositRequests` ```python class DepositRequests(List[DepositRequest]): """ The deposit requests pertaining to a single execution payload. """ LIMIT = MAX_DEPOSIT_REQUESTS_PER_PAYLOAD ``` ### New `PendingConsolidations` ```python class PendingConsolidations(List[PendingConsolidation]): """ The queue of consolidations awaiting processing. """ LIMIT = PENDING_CONSOLIDATIONS_LIMIT ``` ### New `PendingDeposits` ```python class PendingDeposits(List[PendingDeposit]): """ The queue of deposits awaiting processing. """ LIMIT = PENDING_DEPOSITS_LIMIT ``` ### New `PendingPartialWithdrawals` ```python class PendingPartialWithdrawals(List[PendingPartialWithdrawal]): """ The queue of partial withdrawals awaiting processing. """ LIMIT = PENDING_PARTIAL_WITHDRAWALS_LIMIT ``` ### New `WithdrawalRequests` ```python class WithdrawalRequests(List[WithdrawalRequest]): """ The withdrawal requests pertaining to a single execution payload. """ LIMIT = MAX_WITHDRAWAL_REQUESTS_PER_PAYLOAD ``` ## Constants The following values are (non-configurable) constants used throughout the specification. ### Misc | Name | Value | Description | | ------------------------------------ | ------------------- | ------------------------------------------------------ | | `UNSET_DEPOSIT_REQUESTS_START_INDEX` | `Uint64(2**64 - 1)` | Value which indicates no start index has been assigned | | `FULL_EXIT_REQUEST_AMOUNT` | `Gwei(0)` | Withdrawal amount used to signal a full validator exit | ### Withdrawal prefixes | Name | Value | Description | | ------------------------------- | ---------------- | -------------------------------------------------------- | | `COMPOUNDING_WITHDRAWAL_PREFIX` | `Bytes1("0x02")` | Withdrawal credential prefix for a compounding validator | ### Execution-layer triggered requests | Name | Value | | ---------------------------- | ---------------- | | `DEPOSIT_REQUEST_TYPE` | `Bytes1("0x00")` | | `WITHDRAWAL_REQUEST_TYPE` | `Bytes1("0x01")` | | `CONSOLIDATION_REQUEST_TYPE` | `Bytes1("0x02")` | ## Presets ### Gwei values | Name | Value | Description | | ------------------------------- | ------------------------------------------- | ----------------------------------------------------- | | `MIN_ACTIVATION_BALANCE` | `Gwei(2**5 * 10**9)` (= 32,000,000,000) | Minimum balance for a validator to become active | | `MAX_EFFECTIVE_BALANCE_ELECTRA` | `Gwei(2**11 * 10**9)` (= 2,048,000,000,000) | Maximum effective balance for a compounding validator | ### Rewards and penalties | Name | Value | | --------------------------------------- | ------------------------- | | `MIN_SLASHING_PENALTY_QUOTIENT_ELECTRA` | `Uint64(2**12)` (= 4,096) | | `WHISTLEBLOWER_REWARD_QUOTIENT_ELECTRA` | `Uint64(2**12)` (= 4,096) | ### State list lengths | Name | Value | | ----------------------------------- | ------------------------------- | | `PENDING_DEPOSITS_LIMIT` | `Uint64(2**27)` (= 134,217,728) | | `PENDING_PARTIAL_WITHDRAWALS_LIMIT` | `Uint64(2**27)` (= 134,217,728) | | `PENDING_CONSOLIDATIONS_LIMIT` | `Uint64(2**18)` (= 262,144) | ### Max operations per block | Name | Value | | -------------------------------- | -------------------- | | `MAX_ATTESTER_SLASHINGS_ELECTRA` | `Uint64(2**0)` (= 1) | | `MAX_ATTESTATIONS_ELECTRA` | `Uint64(2**3)` (= 8) | ### Execution | Name | Value | Description | | ---------------------------------------- | ------------------------- | ------------------------------------------------------------------------ | | `MAX_DEPOSIT_REQUESTS_PER_PAYLOAD` | `Uint64(2**13)` (= 8,192) | Maximum number of execution-layer deposit requests in each payload | | `MAX_WITHDRAWAL_REQUESTS_PER_PAYLOAD` | `Uint64(2**4)` (= 16) | Maximum number of execution-layer withdrawal requests in each payload | | `MAX_CONSOLIDATION_REQUESTS_PER_PAYLOAD` | `Uint64(2**1)` (= 2) | Maximum number of execution-layer consolidation requests in each payload | ### Withdrawals processing | Name | Value | Description | | -------------------------------------------- | -------------------- | -------------------------------------------------------------------- | | `MAX_PENDING_PARTIALS_PER_WITHDRAWALS_SWEEP` | `Uint64(2**3)` (= 8) | Maximum number of pending partial withdrawals to process per payload | ### Pending deposits processing | Name | Value | Description | | -------------------------------- | --------------------- | ------------------------------------------------------- | | `MAX_PENDING_DEPOSITS_PER_EPOCH` | `Uint64(2**4)` (= 16) | Maximum number of pending deposits to process per epoch | ## Configs ### Execution | Name | Value | Description | | ----------------------------- | ----------- | ------------------------------------------------------------------------------------- | | `MAX_BLOBS_PER_BLOCK_ELECTRA` | `Uint64(9)` | Maximum number of blobs in a single block limited by `MAX_BLOB_COMMITMENTS_PER_BLOCK` | ### Validator cycle | Name | Value | | ------------------------------------------- | ---------------------------------------- | | `MIN_PER_EPOCH_CHURN_LIMIT_ELECTRA` | `Gwei(2**7 * 10**9)` (= 128,000,000,000) | | `MAX_PER_EPOCH_ACTIVATION_EXIT_CHURN_LIMIT` | `Gwei(2**8 * 10**9)` (= 256,000,000,000) | ## Containers ### New containers #### `PendingDeposit` *Note*: The container is new in EIP7251. ```python class PendingDeposit(Container): pubkey: BLSPubkey withdrawal_credentials: Bytes32 amount: Gwei signature: BLSSignature slot: Slot ``` #### `PendingPartialWithdrawal` *Note*: The container is new in EIP7251. ```python class PendingPartialWithdrawal(Container): validator_index: ValidatorIndex amount: Gwei withdrawable_epoch: Epoch ``` #### `PendingConsolidation` *Note*: The container is new in EIP7251. ```python class PendingConsolidation(Container): source_index: ValidatorIndex target_index: ValidatorIndex ``` #### `DepositRequest` *Note*: The container is new in EIP6110. ```python class DepositRequest(Container): pubkey: BLSPubkey withdrawal_credentials: Bytes32 amount: Gwei signature: BLSSignature index: Uint64 ``` #### `WithdrawalRequest` *Note*: The container is new in EIP7251:EIP7002. ```python class WithdrawalRequest(Container): source_address: ExecutionAddress validator_pubkey: BLSPubkey amount: Gwei ``` #### `ConsolidationRequest` *Note*: The container is new in EIP7251. ```python class ConsolidationRequest(Container): source_address: ExecutionAddress source_pubkey: BLSPubkey target_pubkey: BLSPubkey ``` #### `ExecutionRequests` ```python class ExecutionRequests(Container): # [New in Electra:EIP6110] deposits: DepositRequests # [New in Electra:EIP7002:EIP7251] withdrawals: WithdrawalRequests # [New in Electra:EIP7251] consolidations: ConsolidationRequests ``` #### `SingleAttestation` ```python class SingleAttestation(Container): committee_index: CommitteeIndex attester_index: ValidatorIndex data: AttestationData signature: BLSSignature ``` ### Modified containers #### `AttesterSlashing` ```python class AttesterSlashing(Container): # [Modified in Electra:EIP7549] attestation_1: IndexedAttestation # [Modified in Electra:EIP7549] attestation_2: IndexedAttestation ``` #### `BeaconBlockBody` ```python class BeaconBlockBody(Container): randao_reveal: BLSSignature eth1_data: Eth1Data graffiti: Bytes32 proposer_slashings: ProposerSlashings # [Modified in Electra:EIP7549] attester_slashings: AttesterSlashings # [Modified in Electra:EIP7549] attestations: Attestations deposits: Deposits voluntary_exits: VoluntaryExits sync_aggregate: SyncAggregate execution_payload: ExecutionPayload bls_to_execution_changes: BLSToExecutionChanges blob_kzg_commitments: BlobKZGCommitments # [New in Electra] execution_requests: ExecutionRequests ``` #### `Attestation` ```python class Attestation(Container): # [Modified in Electra:EIP7549] aggregation_bits: AggregationBits data: AttestationData signature: BLSSignature # [New in Electra:EIP7549] committee_bits: CommitteeBits ``` #### `IndexedAttestation` ```python class IndexedAttestation(Container): # [Modified in Electra:EIP7549] attesting_indices: AttestingIndices data: AttestationData signature: BLSSignature ``` #### `BeaconState` ```python class BeaconState(Container): genesis_time: Uint64 genesis_validators_root: Root slot: Slot fork: Fork latest_block_header: BeaconBlockHeader block_roots: BlockRoots state_roots: StateRoots historical_roots: HistoricalRoots eth1_data: Eth1Data eth1_data_votes: Eth1DataVotes eth1_deposit_index: Uint64 validators: Validators balances: Balances randao_mixes: RandaoMixes slashings: Slashings previous_epoch_participation: EpochParticipation current_epoch_participation: EpochParticipation justification_bits: JustificationBits previous_justified_checkpoint: Checkpoint current_justified_checkpoint: Checkpoint finalized_checkpoint: Checkpoint inactivity_scores: InactivityScores current_sync_committee: SyncCommittee next_sync_committee: SyncCommittee latest_execution_payload_header: ExecutionPayloadHeader next_withdrawal_index: WithdrawalIndex next_withdrawal_validator_index: ValidatorIndex historical_summaries: HistoricalSummaries # [New in Electra:EIP6110] deposit_requests_start_index: Uint64 # [New in Electra:EIP7251] deposit_balance_to_consume: Gwei # [New in Electra:EIP7251] exit_balance_to_consume: Gwei # [New in Electra:EIP7251] earliest_exit_epoch: Epoch # [New in Electra:EIP7251] consolidation_balance_to_consume: Gwei # [New in Electra:EIP7251] earliest_consolidation_epoch: Epoch # [New in Electra:EIP7251] pending_deposits: PendingDeposits # [New in Electra:EIP7251] pending_partial_withdrawals: PendingPartialWithdrawals # [New in Electra:EIP7251] pending_consolidations: PendingConsolidations ``` #### `NewPayloadRequest` ```python class NewPayloadRequest(Container): execution_payload: ExecutionPayload versioned_hashes: VersionedHashes parent_beacon_block_root: Root # [New in Electra] execution_requests: ExecutionRequests ``` ## Dataclasses ### Modified dataclasses #### `ExpectedWithdrawals` ```python @dataclass class ExpectedWithdrawals: withdrawals: Sequence[Withdrawal] # [New in Electra:EIP7251] processed_partial_withdrawals_count: Uint64 processed_sweep_withdrawals_count: Uint64 ``` ## Helpers ### Predicates #### Modified `compute_proposer_index` *Note*: The function `compute_proposer_index` is modified to use `MAX_EFFECTIVE_BALANCE_ELECTRA` and to use a 16-bit random value instead of an 8-bit random byte in the effective balance filter. ```python def compute_proposer_index( state: BeaconState, indices: Sequence[ValidatorIndex], seed: Bytes32 ) -> ValidatorIndex: """ Return from ``indices`` a random index sampled by effective balance. """ assert len(indices) > 0 # [Modified in Electra] MAX_RANDOM_VALUE = 2**16 - 1 i = Uint64(0) total = Uint64(len(indices)) while True: candidate_index = indices[compute_shuffled_index(i % total, total, seed)] # [Modified in Electra] random_bytes = sha256(seed + uint_to_bytes(i // 16)) offset = i % 16 * 2 random_value = bytes_to_uint64(random_bytes[offset : offset + 2]) effective_balance = state.validators[candidate_index].effective_balance # [Modified in Electra:EIP7251] if effective_balance * MAX_RANDOM_VALUE >= MAX_EFFECTIVE_BALANCE_ELECTRA * random_value: return candidate_index i += 1 ``` #### Modified `is_eligible_for_activation_queue` *Note*: The function `is_eligible_for_activation_queue` is modified to use `MIN_ACTIVATION_BALANCE` instead of `MAX_EFFECTIVE_BALANCE`. ```python def is_eligible_for_activation_queue(validator: Validator) -> bool: """ Check if ``validator`` is eligible to be placed into the activation queue. """ return ( validator.activation_eligibility_epoch == FAR_FUTURE_EPOCH # [Modified in Electra:EIP7251] and validator.effective_balance >= MIN_ACTIVATION_BALANCE ) ``` #### New `is_compounding_withdrawal_credential` ```python def is_compounding_withdrawal_credential(withdrawal_credentials: Bytes32) -> bool: return withdrawal_credentials[:1] == COMPOUNDING_WITHDRAWAL_PREFIX ``` #### New `has_compounding_withdrawal_credential` ```python def has_compounding_withdrawal_credential(validator: Validator) -> bool: """ Check if ``validator`` has an 0x02 prefixed "compounding" withdrawal credential. """ return is_compounding_withdrawal_credential(validator.withdrawal_credentials) ``` #### New `has_execution_withdrawal_credential` ```python def has_execution_withdrawal_credential(validator: Validator) -> bool: """ Check if ``validator`` has a 0x01 or 0x02 prefixed withdrawal credential. """ return ( has_eth1_withdrawal_credential(validator) # 0x01 or has_compounding_withdrawal_credential(validator) # 0x02 ) ``` #### Modified `is_fully_withdrawable_validator` *Note*: The function `is_fully_withdrawable_validator` is modified to use `has_execution_withdrawal_credential` instead of `has_eth1_withdrawal_credential`. ```python def is_fully_withdrawable_validator(validator: Validator, balance: Gwei, epoch: Epoch) -> bool: """ Check if ``validator`` is fully withdrawable. """ return ( # [Modified in Electra:EIP7251] has_execution_withdrawal_credential(validator) and validator.withdrawable_epoch <= epoch and balance > 0 ) ``` #### Modified `is_partially_withdrawable_validator` *Note*: The function `is_partially_withdrawable_validator` is modified to use `get_max_effective_balance` instead of `MAX_EFFECTIVE_BALANCE` and `has_execution_withdrawal_credential` instead of `has_eth1_withdrawal_credential`. ```python def is_partially_withdrawable_validator(validator: Validator, balance: Gwei) -> bool: """ Check if ``validator`` is partially withdrawable. """ max_effective_balance = get_max_effective_balance(validator) # [Modified in Electra:EIP7251] has_max_effective_balance = validator.effective_balance == max_effective_balance # [Modified in Electra:EIP7251] has_excess_balance = balance > max_effective_balance return ( # [Modified in Electra:EIP7251] has_execution_withdrawal_credential(validator) and has_max_effective_balance and has_excess_balance ) ``` #### New `is_eligible_for_partial_withdrawals` ```python def is_eligible_for_partial_withdrawals(validator: Validator, balance: Gwei) -> bool: """ Check if ``validator`` can process a pending partial withdrawal. """ has_sufficient_effective_balance = validator.effective_balance >= MIN_ACTIVATION_BALANCE has_excess_balance = balance > MIN_ACTIVATION_BALANCE return ( validator.exit_epoch == FAR_FUTURE_EPOCH and has_sufficient_effective_balance and has_excess_balance ) ``` ### Misc #### New `get_committee_indices` ```python def get_committee_indices(committee_bits: BitVector) -> Sequence[CommitteeIndex]: return [CommitteeIndex(index) for index, bit in enumerate(committee_bits) if bit] ``` #### New `get_max_effective_balance` ```python def get_max_effective_balance(validator: Validator) -> Gwei: """ Get max effective balance for ``validator``. """ if has_compounding_withdrawal_credential(validator): return MAX_EFFECTIVE_BALANCE_ELECTRA else: return MIN_ACTIVATION_BALANCE ``` ### Beacon state accessors #### New `get_balance_churn_limit` ```python def get_balance_churn_limit(state: BeaconState) -> Gwei: """ Return the churn limit for the current epoch. """ churn = max( MIN_PER_EPOCH_CHURN_LIMIT_ELECTRA, get_total_active_balance(state) // CHURN_LIMIT_QUOTIENT ) return churn - churn % EFFECTIVE_BALANCE_INCREMENT ``` #### New `get_activation_exit_churn_limit` ```python def get_activation_exit_churn_limit(state: BeaconState) -> Gwei: """ Return the churn limit for the current epoch dedicated to activations and exits. """ return min(MAX_PER_EPOCH_ACTIVATION_EXIT_CHURN_LIMIT, get_balance_churn_limit(state)) ``` #### New `get_consolidation_churn_limit` ```python def get_consolidation_churn_limit(state: BeaconState) -> Gwei: return get_balance_churn_limit(state) - get_activation_exit_churn_limit(state) ``` #### New `get_pending_balance_to_withdraw` ```python def get_pending_balance_to_withdraw(state: BeaconState, validator_index: ValidatorIndex) -> Gwei: balance = Gwei(0) for withdrawal in state.pending_partial_withdrawals: if withdrawal.validator_index == validator_index: balance += withdrawal.amount return balance ``` #### Modified `get_attesting_indices` *Note*: The function `get_attesting_indices` is modified to support EIP7549. ```python def get_attesting_indices(state: BeaconState, attestation: Attestation) -> set[ValidatorIndex]: """ Return the set of attesting indices corresponding to ``aggregation_bits`` and ``committee_bits``. """ output: set[ValidatorIndex] = set() committee_indices = get_committee_indices(attestation.committee_bits) committee_offset = 0 for committee_index in committee_indices: committee = get_beacon_committee(state, attestation.data.slot, committee_index) committee_attesters = { attester_index for index, attester_index in enumerate(committee) if attestation.aggregation_bits[committee_offset + index] } output = output.union(committee_attesters) committee_offset += len(committee) return output ``` #### Modified `get_next_sync_committee_indices` *Note*: The function `get_next_sync_committee_indices` is modified to use `MAX_EFFECTIVE_BALANCE_ELECTRA` and to use a 16-bit random value instead of an 8-bit random byte in the effective balance filter. ```python def get_next_sync_committee_indices(state: BeaconState) -> Sequence[ValidatorIndex]: """ Return the sync committee indices, with possible duplicates, for the next sync committee. """ epoch = get_current_epoch(state) + 1 # [Modified in Electra] MAX_RANDOM_VALUE = 2**16 - 1 active_validator_indices = get_active_validator_indices(state, epoch) active_validator_count = Uint64(len(active_validator_indices)) seed = get_seed(state, epoch, DOMAIN_SYNC_COMMITTEE) i = Uint64(0) sync_committee_indices: list[ValidatorIndex] = [] while len(sync_committee_indices) < SYNC_COMMITTEE_SIZE: shuffled_index = compute_shuffled_index( Uint64(i % active_validator_count), active_validator_count, seed ) candidate_index = active_validator_indices[shuffled_index] # [Modified in Electra] random_bytes = sha256(seed + uint_to_bytes(i // 16)) offset = i % 16 * 2 random_value = bytes_to_uint64(random_bytes[offset : offset + 2]) effective_balance = state.validators[candidate_index].effective_balance # [Modified in Electra:EIP7251] if effective_balance * MAX_RANDOM_VALUE >= MAX_EFFECTIVE_BALANCE_ELECTRA * random_value: sync_committee_indices.append(candidate_index) i += 1 return sync_committee_indices ``` ### Beacon state mutators #### Modified `initiate_validator_exit` *Note*: The function `initiate_validator_exit` is modified to use the new `compute_exit_epoch_and_update_churn` function. ```python def initiate_validator_exit(state: BeaconState, index: ValidatorIndex) -> None: """ Initiate the exit of the validator with index ``index``. """ # Return if validator already initiated exit validator = state.validators[index] if validator.exit_epoch != FAR_FUTURE_EPOCH: return # Compute exit queue epoch [Modified in Electra:EIP7251] exit_queue_epoch = compute_exit_epoch_and_update_churn(state, validator.effective_balance) # Set validator exit epoch and withdrawable epoch validator.exit_epoch = exit_queue_epoch validator.withdrawable_epoch = validator.exit_epoch + MIN_VALIDATOR_WITHDRAWABILITY_DELAY ``` #### New `switch_to_compounding_validator` ```python def switch_to_compounding_validator(state: BeaconState, index: ValidatorIndex) -> None: validator = state.validators[index] validator.withdrawal_credentials = Bytes32( COMPOUNDING_WITHDRAWAL_PREFIX + validator.withdrawal_credentials[1:] ) queue_excess_active_balance(state, index) ``` #### New `queue_excess_active_balance` ```python def queue_excess_active_balance(state: BeaconState, index: ValidatorIndex) -> None: balance = state.balances[index] if balance > MIN_ACTIVATION_BALANCE: excess_balance = balance - MIN_ACTIVATION_BALANCE state.balances[index] = MIN_ACTIVATION_BALANCE validator = state.validators[index] # Use G2_POINT_AT_INFINITY as a signature field placeholder # and GENESIS_SLOT to distinguish from a pending deposit request state.pending_deposits.append( PendingDeposit( pubkey=validator.pubkey, withdrawal_credentials=validator.withdrawal_credentials, amount=excess_balance, signature=G2_POINT_AT_INFINITY, slot=GENESIS_SLOT, ) ) ``` #### New `compute_exit_epoch_and_update_churn` ```python def compute_exit_epoch_and_update_churn(state: BeaconState, exit_balance: Gwei) -> Epoch: earliest_exit_epoch = max( state.earliest_exit_epoch, compute_activation_exit_epoch(get_current_epoch(state)) ) per_epoch_churn = get_activation_exit_churn_limit(state) # New epoch for exits. if state.earliest_exit_epoch < earliest_exit_epoch: exit_balance_to_consume = per_epoch_churn else: exit_balance_to_consume = state.exit_balance_to_consume # Exit doesn't fit in the current earliest epoch. if exit_balance > exit_balance_to_consume: balance_to_process = exit_balance - exit_balance_to_consume additional_epochs = (balance_to_process - 1) // per_epoch_churn + 1 earliest_exit_epoch += Epoch(additional_epochs) exit_balance_to_consume += additional_epochs * per_epoch_churn # Consume the balance and update state variables. state.exit_balance_to_consume = exit_balance_to_consume - exit_balance state.earliest_exit_epoch = earliest_exit_epoch return state.earliest_exit_epoch ``` #### New `compute_consolidation_epoch_and_update_churn` ```python def compute_consolidation_epoch_and_update_churn( state: BeaconState, consolidation_balance: Gwei ) -> Epoch: earliest_consolidation_epoch = max( state.earliest_consolidation_epoch, compute_activation_exit_epoch(get_current_epoch(state)) ) per_epoch_consolidation_churn = get_consolidation_churn_limit(state) # New epoch for consolidations. if state.earliest_consolidation_epoch < earliest_consolidation_epoch: consolidation_balance_to_consume = per_epoch_consolidation_churn else: consolidation_balance_to_consume = state.consolidation_balance_to_consume # Consolidation doesn't fit in the current earliest epoch. if consolidation_balance > consolidation_balance_to_consume: balance_to_process = consolidation_balance - consolidation_balance_to_consume additional_epochs = (balance_to_process - 1) // per_epoch_consolidation_churn + 1 earliest_consolidation_epoch += Epoch(additional_epochs) consolidation_balance_to_consume += additional_epochs * per_epoch_consolidation_churn # Consume the balance and update state variables. state.consolidation_balance_to_consume = ( consolidation_balance_to_consume - consolidation_balance ) state.earliest_consolidation_epoch = earliest_consolidation_epoch return state.earliest_consolidation_epoch ``` #### Modified `slash_validator` *Note*: The function `slash_validator` is modified to change how the slashing penalty and proposer/whistleblower rewards are calculated in accordance with EIP7251. ```python def slash_validator( state: BeaconState, slashed_index: ValidatorIndex, whistleblower_index: ValidatorIndex | None = None, ) -> None: """ Slash the validator with index ``slashed_index``. """ epoch = get_current_epoch(state) initiate_validator_exit(state, slashed_index) validator = state.validators[slashed_index] validator.slashed = Boolean(True) validator.withdrawable_epoch = max( validator.withdrawable_epoch, epoch + EPOCHS_PER_SLASHINGS_VECTOR ) state.slashings[epoch % EPOCHS_PER_SLASHINGS_VECTOR] += validator.effective_balance # [Modified in Electra:EIP7251] slashing_penalty = validator.effective_balance // MIN_SLASHING_PENALTY_QUOTIENT_ELECTRA decrease_balance(state, slashed_index, slashing_penalty) # Apply proposer and whistleblower rewards proposer_index = get_beacon_proposer_index(state) if whistleblower_index is None: whistleblower_index = proposer_index # [Modified in Electra:EIP7251] whistleblower_reward = validator.effective_balance // WHISTLEBLOWER_REWARD_QUOTIENT_ELECTRA proposer_reward = whistleblower_reward * PROPOSER_WEIGHT // WEIGHT_DENOMINATOR increase_balance(state, proposer_index, proposer_reward) increase_balance(state, whistleblower_index, whistleblower_reward - proposer_reward) ``` ## Beacon chain state transition function ### Epoch processing #### Modified `process_epoch` *Note*: The function `process_epoch` is modified to call updated functions and to process pending balance deposits and pending consolidations which are new in Electra. ```python def process_epoch(state: BeaconState) -> None: process_justification_and_finalization(state) process_inactivity_updates(state) process_rewards_and_penalties(state) # [Modified in Electra:EIP7251] process_registry_updates(state) # [Modified in Electra:EIP7251] process_slashings(state) process_eth1_data_reset(state) # [New in Electra:EIP7251] process_pending_deposits(state) # [New in Electra:EIP7251] process_pending_consolidations(state) # [Modified in Electra:EIP7251] process_effective_balance_updates(state) process_slashings_reset(state) process_randao_mixes_reset(state) process_historical_summaries_update(state) process_participation_flag_updates(state) process_sync_committee_updates(state) ``` #### Modified `process_registry_updates` *Note*: The function `process_registry_updates` is modified to use the updated definitions of `initiate_validator_exit` and `is_eligible_for_activation_queue`, changes how the activation epochs are computed for eligible validators, and processes activations in the same loop as activation eligibility updates and ejections. ```python def process_registry_updates(state: BeaconState) -> None: current_epoch = get_current_epoch(state) activation_epoch = compute_activation_exit_epoch(current_epoch) # Process activation eligibility, ejections, and activations for index, validator in enumerate(state.validators): # [Modified in Electra:EIP7251] if is_eligible_for_activation_queue(validator): validator.activation_eligibility_epoch = current_epoch + 1 elif ( is_active_validator(validator, current_epoch) and validator.effective_balance <= EJECTION_BALANCE ): # [Modified in Electra:EIP7251] initiate_validator_exit(state, ValidatorIndex(index)) elif is_eligible_for_activation(state, validator): validator.activation_epoch = activation_epoch ``` #### Modified `process_slashings` *Note*: The function `process_slashings` is modified to use a new algorithm to compute correlation penalty. ```python def process_slashings(state: BeaconState) -> None: epoch = get_current_epoch(state) total_balance = get_total_active_balance(state) adjusted_total_slashing_balance = min( Gwei(sum(state.slashings)) * PROPORTIONAL_SLASHING_MULTIPLIER_BELLATRIX, total_balance ) increment = ( EFFECTIVE_BALANCE_INCREMENT # Factored out from total balance to avoid Uint64 overflow ) penalty_per_effective_balance_increment = adjusted_total_slashing_balance // ( total_balance // increment ) for index, validator in enumerate(state.validators): if ( validator.slashed and epoch + EPOCHS_PER_SLASHINGS_VECTOR // 2 == validator.withdrawable_epoch ): effective_balance_increments = validator.effective_balance // increment # [Modified in Electra:EIP7251] penalty = penalty_per_effective_balance_increment * effective_balance_increments decrease_balance(state, ValidatorIndex(index), penalty) ``` #### New `apply_pending_deposit` ```python def apply_pending_deposit(state: BeaconState, deposit: PendingDeposit) -> None: """ Applies ``deposit`` to the ``state``. """ validator_pubkeys = [validator.pubkey for validator in state.validators] if deposit.pubkey not in validator_pubkeys: # Verify the deposit signature (proof of possession) which is not checked by the deposit contract if is_valid_deposit_signature( deposit.pubkey, deposit.withdrawal_credentials, deposit.amount, deposit.signature ): add_validator_to_registry( state, deposit.pubkey, deposit.withdrawal_credentials, deposit.amount ) else: validator_index = ValidatorIndex(validator_pubkeys.index(deposit.pubkey)) increase_balance(state, validator_index, deposit.amount) ``` #### New `process_pending_deposits` Iterating over `pending_deposits` queue this function runs the following checks before applying pending deposit: 1. All Eth1 bridge deposits are processed before the first deposit request gets processed. 2. Deposit position in the queue is finalized. 3. Deposit does not exceed the `MAX_PENDING_DEPOSITS_PER_EPOCH` limit. 4. Deposit does not exceed the activation churn limit. ```python def process_pending_deposits(state: BeaconState) -> None: next_epoch = get_current_epoch(state) + 1 available_for_processing = state.deposit_balance_to_consume + get_activation_exit_churn_limit( state ) processed_amount = 0 next_deposit_index = 0 deposits_to_postpone = [] is_churn_limit_reached = False finalized_slot = compute_start_slot_at_epoch(state.finalized_checkpoint.epoch) for deposit in state.pending_deposits: # Do not process deposit requests if Eth1 bridge deposits are not yet applied. if ( # Is deposit request deposit.slot > GENESIS_SLOT and # There are pending Eth1 bridge deposits state.eth1_deposit_index < state.deposit_requests_start_index ): break # Check if deposit has been finalized, otherwise, stop processing. if deposit.slot > finalized_slot: break # Check if number of processed deposits has not reached the limit, otherwise, stop processing. if next_deposit_index >= MAX_PENDING_DEPOSITS_PER_EPOCH: break # Read validator state is_validator_exited = False is_validator_withdrawn = False validator_pubkeys = [validator.pubkey for validator in state.validators] if deposit.pubkey in validator_pubkeys: validator = state.validators[ValidatorIndex(validator_pubkeys.index(deposit.pubkey))] is_validator_exited = validator.exit_epoch < FAR_FUTURE_EPOCH is_validator_withdrawn = validator.withdrawable_epoch < next_epoch if is_validator_withdrawn: # Deposited balance will never become active. Increase balance but do not consume churn apply_pending_deposit(state, deposit) elif is_validator_exited: # Validator is exiting, postpone the deposit until after withdrawable epoch deposits_to_postpone.append(deposit) else: # Check if deposit fits in the churn, otherwise, do no more deposit processing in this epoch. is_churn_limit_reached = processed_amount + deposit.amount > available_for_processing if is_churn_limit_reached: break # Consume churn and apply deposit. processed_amount += deposit.amount apply_pending_deposit(state, deposit) # Regardless of how the deposit was handled, we move on in the queue. next_deposit_index += 1 state.pending_deposits = state.pending_deposits[next_deposit_index:] + deposits_to_postpone # Accumulate churn only if the churn limit has been hit. if is_churn_limit_reached: state.deposit_balance_to_consume = available_for_processing - processed_amount else: state.deposit_balance_to_consume = Gwei(0) ``` #### New `process_pending_consolidations` ```python def process_pending_consolidations(state: BeaconState) -> None: next_epoch = get_current_epoch(state) + 1 next_pending_consolidation = 0 for pending_consolidation in state.pending_consolidations: source_validator = state.validators[pending_consolidation.source_index] if source_validator.slashed: next_pending_consolidation += 1 continue if source_validator.withdrawable_epoch > next_epoch: break # Calculate the consolidated balance source_effective_balance = min( state.balances[pending_consolidation.source_index], source_validator.effective_balance ) # Move active balance to target. Excess balance is withdrawable. decrease_balance(state, pending_consolidation.source_index, source_effective_balance) increase_balance(state, pending_consolidation.target_index, source_effective_balance) next_pending_consolidation += 1 state.pending_consolidations = state.pending_consolidations[next_pending_consolidation:] ``` #### Modified `process_effective_balance_updates` *Note*: The function `process_effective_balance_updates` is modified to use the new limit for the maximum effective balance. ```python def process_effective_balance_updates(state: BeaconState) -> None: # Update effective balances with hysteresis for index, validator in enumerate(state.validators): balance = state.balances[index] HYSTERESIS_INCREMENT = Uint64(EFFECTIVE_BALANCE_INCREMENT // HYSTERESIS_QUOTIENT) DOWNWARD_THRESHOLD = HYSTERESIS_INCREMENT * HYSTERESIS_DOWNWARD_MULTIPLIER UPWARD_THRESHOLD = HYSTERESIS_INCREMENT * HYSTERESIS_UPWARD_MULTIPLIER # [Modified in Electra:EIP7251] max_effective_balance = get_max_effective_balance(validator) if ( balance + DOWNWARD_THRESHOLD < validator.effective_balance or validator.effective_balance + UPWARD_THRESHOLD < balance ): validator.effective_balance = min( balance - balance % EFFECTIVE_BALANCE_INCREMENT, max_effective_balance ) ``` ### Execution engine #### Engine APIs ##### Modified `is_valid_block_hash` *Note*: The function `is_valid_block_hash` is modified to include the additional `execution_requests_list`. ```python def is_valid_block_hash( self: ExecutionEngine, execution_payload: ExecutionPayload, parent_beacon_block_root: Root, execution_requests_list: Sequence[bytes], ) -> bool: """ Return ``True`` if and only if ``execution_payload.block_hash`` is computed correctly. """ ``` ##### Modified `notify_new_payload` *Note*: The function `notify_new_payload` is modified to include the additional `execution_requests_list`. ```python def notify_new_payload( self: ExecutionEngine, execution_payload: ExecutionPayload, parent_beacon_block_root: Root, execution_requests_list: Sequence[bytes], ) -> bool: """ Return ``True`` if and only if ``execution_payload`` and ``execution_requests_list`` are valid with respect to ``self.execution_state``. """ ``` ##### Modified `verify_and_notify_new_payload` *Note*: The function `verify_and_notify_new_payload` is modified to pass the additional parameter `execution_requests_list` when calling `is_valid_block_hash` and `notify_new_payload` in Electra. ```python def verify_and_notify_new_payload( self: ExecutionEngine, new_payload_request: NewPayloadRequest ) -> bool: """ Return ``True`` if and only if ``new_payload_request`` is valid with respect to ``self.execution_state``. """ execution_payload = new_payload_request.execution_payload parent_beacon_block_root = new_payload_request.parent_beacon_block_root # [New in Electra] execution_requests_list = get_execution_requests_list(new_payload_request.execution_requests) if b"" in execution_payload.transactions: return False # [Modified in Electra] if not self.is_valid_block_hash( execution_payload, parent_beacon_block_root, execution_requests_list ): return False if not self.is_valid_versioned_hashes(new_payload_request): return False # [Modified in Electra] if not self.notify_new_payload( execution_payload, parent_beacon_block_root, execution_requests_list ): return False return True ``` ### Block processing ```python def process_block(state: BeaconState, block: BeaconBlock) -> None: process_block_header(state, block) # [Modified in Electra:EIP7251] process_withdrawals(state, block.body.execution_payload) # [Modified in Electra:EIP6110] process_execution_payload(state, block.body, EXECUTION_ENGINE) process_randao(state, block.body) process_eth1_data(state, block.body) # [Modified in Electra:EIP6110:EIP7002:EIP7549:EIP7251] process_operations(state, block.body) process_sync_aggregate(state, block.body.sync_aggregate) ``` #### Withdrawals ##### New `get_pending_partial_withdrawals` ```python def get_pending_partial_withdrawals( state: BeaconState, withdrawal_index: WithdrawalIndex, prior_withdrawals: Sequence[Withdrawal], ) -> tuple[Sequence[Withdrawal], WithdrawalIndex, Uint64]: epoch = get_current_epoch(state) withdrawals_limit = min( len(prior_withdrawals) + MAX_PENDING_PARTIALS_PER_WITHDRAWALS_SWEEP, MAX_WITHDRAWALS_PER_PAYLOAD - 1, ) assert len(prior_withdrawals) <= withdrawals_limit processed_count = Uint64(0) withdrawals: list[Withdrawal] = [] for withdrawal in state.pending_partial_withdrawals: all_withdrawals = list(prior_withdrawals) + withdrawals is_withdrawable = withdrawal.withdrawable_epoch <= epoch has_reached_limit = len(all_withdrawals) >= withdrawals_limit if not is_withdrawable or has_reached_limit: break validator_index = withdrawal.validator_index validator = state.validators[validator_index] balance = get_balance_after_withdrawals(state, validator_index, all_withdrawals) if is_eligible_for_partial_withdrawals(validator, balance): withdrawal_amount = min(balance - MIN_ACTIVATION_BALANCE, withdrawal.amount) withdrawals.append( Withdrawal( index=withdrawal_index, validator_index=validator_index, address=ExecutionAddress(validator.withdrawal_credentials[12:]), amount=withdrawal_amount, ) ) withdrawal_index += 1 processed_count += 1 return withdrawals, withdrawal_index, processed_count ``` ##### Modified `get_validators_sweep_withdrawals` *Note*: The function `get_validators_sweep_withdrawals` is modified to use `get_max_effective_balance`. ```python def get_validators_sweep_withdrawals( state: BeaconState, withdrawal_index: WithdrawalIndex, prior_withdrawals: Sequence[Withdrawal], ) -> tuple[Sequence[Withdrawal], WithdrawalIndex, Uint64]: epoch = get_current_epoch(state) validators_limit = min(len(state.validators), MAX_VALIDATORS_PER_WITHDRAWALS_SWEEP) withdrawals_limit = MAX_WITHDRAWALS_PER_PAYLOAD # There must be at least one space reserved for validator sweep withdrawals assert len(prior_withdrawals) < withdrawals_limit processed_count = Uint64(0) withdrawals: list[Withdrawal] = [] validator_index = state.next_withdrawal_validator_index for _ in range(validators_limit): all_withdrawals = list(prior_withdrawals) + withdrawals has_reached_limit = len(all_withdrawals) >= withdrawals_limit if has_reached_limit: break validator = state.validators[validator_index] balance = get_balance_after_withdrawals(state, validator_index, all_withdrawals) if is_fully_withdrawable_validator(validator, balance, epoch): withdrawals.append( Withdrawal( index=withdrawal_index, validator_index=validator_index, address=ExecutionAddress(validator.withdrawal_credentials[12:]), amount=balance, ) ) withdrawal_index += 1 elif is_partially_withdrawable_validator(validator, balance): withdrawals.append( Withdrawal( index=withdrawal_index, validator_index=validator_index, address=ExecutionAddress(validator.withdrawal_credentials[12:]), # [Modified in Electra:EIP7251] amount=balance - get_max_effective_balance(validator), ) ) withdrawal_index += 1 validator_index = (validator_index + 1) % len(state.validators) processed_count += 1 return withdrawals, withdrawal_index, processed_count ``` ##### Modified `get_expected_withdrawals` *Note*: The function `get_expected_withdrawals` is modified to support EIP7251. ```python def get_expected_withdrawals(state: BeaconState) -> ExpectedWithdrawals: withdrawal_index = state.next_withdrawal_index withdrawals: list[Withdrawal] = [] # [New in Electra:EIP7251] # Get partial withdrawals partial_withdrawals, withdrawal_index, processed_partial_withdrawals_count = ( get_pending_partial_withdrawals(state, withdrawal_index, withdrawals) ) withdrawals.extend(partial_withdrawals) # Get validators sweep withdrawals validators_sweep_withdrawals, withdrawal_index, processed_validators_sweep_count = ( get_validators_sweep_withdrawals(state, withdrawal_index, withdrawals) ) withdrawals.extend(validators_sweep_withdrawals) return ExpectedWithdrawals( withdrawals, # [New in Electra:EIP7251] processed_partial_withdrawals_count, processed_validators_sweep_count, ) ``` ##### New `update_pending_partial_withdrawals` ```python def update_pending_partial_withdrawals( state: BeaconState, processed_partial_withdrawals_count: Uint64 ) -> None: state.pending_partial_withdrawals = state.pending_partial_withdrawals[ processed_partial_withdrawals_count: ] ``` ##### Modified `process_withdrawals` *Note*: The function `process_withdrawals` is modified to support EIP7251. ```python def process_withdrawals(state: BeaconState, payload: ExecutionPayload) -> None: # Get expected withdrawals expected = get_expected_withdrawals(state) assert list(payload.withdrawals) == expected.withdrawals # Apply expected withdrawals apply_withdrawals(state, expected.withdrawals) # Update withdrawals fields in the state update_next_withdrawal_index(state, expected.withdrawals) # [New in Electra:EIP7251] update_pending_partial_withdrawals(state, expected.processed_partial_withdrawals_count) update_next_withdrawal_validator_index(state, expected.withdrawals) ``` #### Execution payload ##### New `get_execution_requests_list` *Note*: Encodes execution requests as defined by [EIP-7685](https://eips.ethereum.org/EIPS/eip-7685). ```python def get_execution_requests_list(execution_requests: ExecutionRequests) -> Sequence[bytes]: requests: Sequence[tuple[Bytes1, List]] = [ (DEPOSIT_REQUEST_TYPE, execution_requests.deposits), (WITHDRAWAL_REQUEST_TYPE, execution_requests.withdrawals), (CONSOLIDATION_REQUEST_TYPE, execution_requests.consolidations), ] return [ request_type + ssz_serialize(request_data) for request_type, request_data in requests if len(request_data) != 0 ] ``` ##### Modified `process_execution_payload` *Note*: The function `process_execution_payload` is modified to pass `execution_requests` into `execution_engine.verify_and_notify_new_payload` (via the updated `NewPayloadRequest`). ```python def process_execution_payload( state: BeaconState, body: BeaconBlockBody, execution_engine: ExecutionEngine ) -> None: payload = body.execution_payload # Verify consistency of the parent hash with respect to the previous execution payload header assert payload.parent_hash == state.latest_execution_payload_header.block_hash # Verify prev_randao assert payload.prev_randao == get_randao_mix(state, get_current_epoch(state)) # Verify timestamp assert payload.timestamp == compute_time_at_slot(state.genesis_time, state.slot) # [Modified in Electra:EIP7691] # Verify commitments are under limit assert len(body.blob_kzg_commitments) <= MAX_BLOBS_PER_BLOCK_ELECTRA # Compute versioned hashes versioned_hashes = VersionedHashes() for commitment in body.blob_kzg_commitments: versioned_hashes.append(kzg_commitment_to_versioned_hash(commitment)) # Verify the execution payload is valid assert execution_engine.verify_and_notify_new_payload( NewPayloadRequest( execution_payload=payload, versioned_hashes=versioned_hashes, parent_beacon_block_root=state.latest_block_header.parent_root, # [New in Electra] execution_requests=body.execution_requests, ) ) # Cache execution payload header state.latest_execution_payload_header = ExecutionPayloadHeader( parent_hash=payload.parent_hash, fee_recipient=payload.fee_recipient, state_root=payload.state_root, receipts_root=payload.receipts_root, logs_bloom=payload.logs_bloom, prev_randao=payload.prev_randao, block_number=payload.block_number, gas_limit=payload.gas_limit, gas_used=payload.gas_used, timestamp=payload.timestamp, extra_data=payload.extra_data, base_fee_per_gas=payload.base_fee_per_gas, block_hash=payload.block_hash, transactions_root=hash_tree_root(payload.transactions), withdrawals_root=hash_tree_root(payload.withdrawals), blob_gas_used=payload.blob_gas_used, excess_blob_gas=payload.excess_blob_gas, ) ``` #### Operations ##### Modified `process_operations` *Note*: The function `process_operations` is modified to support all of the new functionality in Electra. ```python def process_operations(state: BeaconState, body: BeaconBlockBody) -> None: # [Modified in Electra:EIP6110] # Disable former deposit mechanism once all prior deposits are processed eth1_deposit_index_limit = min( state.eth1_data.deposit_count, state.deposit_requests_start_index ) if state.eth1_deposit_index < eth1_deposit_index_limit: assert len(body.deposits) == min( MAX_DEPOSITS, eth1_deposit_index_limit - state.eth1_deposit_index ) else: assert len(body.deposits) == 0 def for_ops(operations: Sequence[Any], fn: Callable[[BeaconState, Any], None]) -> None: for operation in operations: fn(state, operation) for_ops(body.proposer_slashings, process_proposer_slashing) for_ops(body.attester_slashings, process_attester_slashing) # [Modified in Electra:EIP7549] for_ops(body.attestations, process_attestation) for_ops(body.deposits, process_deposit) # [Modified in Electra:EIP7251] for_ops(body.voluntary_exits, process_voluntary_exit) for_ops(body.bls_to_execution_changes, process_bls_to_execution_change) # [New in Electra:EIP6110] for_ops(body.execution_requests.deposits, process_deposit_request) # [New in Electra:EIP7002:EIP7251] for_ops(body.execution_requests.withdrawals, process_withdrawal_request) # [New in Electra:EIP7251] for_ops(body.execution_requests.consolidations, process_consolidation_request) ``` ##### Attestations ###### Modified `process_attestation` *Note*: The function is modified to support EIP7549. ```python def process_attestation(state: BeaconState, attestation: Attestation) -> None: data = attestation.data assert data.target.epoch in (get_previous_epoch(state), get_current_epoch(state)) assert data.target.epoch == compute_epoch_at_slot(data.slot) assert data.slot + MIN_ATTESTATION_INCLUSION_DELAY <= state.slot # [Modified in Electra:EIP7549] assert data.index == 0 committee_indices = get_committee_indices(attestation.committee_bits) committee_offset = 0 for committee_index in committee_indices: assert committee_index < get_committee_count_per_slot(state, data.target.epoch) committee = get_beacon_committee(state, data.slot, committee_index) committee_attesters = { attester_index for index, attester_index in enumerate(committee) if attestation.aggregation_bits[committee_offset + index] } assert len(committee_attesters) > 0 committee_offset += len(committee) # Bitfield length matches total number of participants assert len(attestation.aggregation_bits) == committee_offset # Participation flag indices participation_flag_indices = get_attestation_participation_flag_indices( state, data, state.slot - data.slot ) # Verify signature assert is_valid_indexed_attestation(state, get_indexed_attestation(state, attestation)) # Update epoch participation flags if data.target.epoch == get_current_epoch(state): epoch_participation = state.current_epoch_participation else: epoch_participation = state.previous_epoch_participation proposer_reward_numerator = 0 for index in get_attesting_indices(state, attestation): for flag_index, weight in enumerate(PARTICIPATION_FLAG_WEIGHTS): if flag_index in participation_flag_indices and not has_flag( epoch_participation[index], flag_index ): epoch_participation[index] = add_flag(epoch_participation[index], flag_index) proposer_reward_numerator += get_base_reward(state, index) * weight # Reward proposer proposer_reward_denominator = ( (WEIGHT_DENOMINATOR - PROPOSER_WEIGHT) * WEIGHT_DENOMINATOR // PROPOSER_WEIGHT ) proposer_reward = Gwei(proposer_reward_numerator // proposer_reward_denominator) increase_balance(state, get_beacon_proposer_index(state), proposer_reward) ``` ##### Deposits ###### Modified `get_validator_from_deposit` *Note*: The function is modified to use `MAX_EFFECTIVE_BALANCE_ELECTRA` for compounding withdrawal credential. ```python def get_validator_from_deposit( pubkey: BLSPubkey, withdrawal_credentials: Bytes32, amount: Gwei ) -> Validator: validator = Validator( pubkey=pubkey, withdrawal_credentials=withdrawal_credentials, effective_balance=Gwei(0), slashed=Boolean(False), activation_eligibility_epoch=FAR_FUTURE_EPOCH, activation_epoch=FAR_FUTURE_EPOCH, exit_epoch=FAR_FUTURE_EPOCH, withdrawable_epoch=FAR_FUTURE_EPOCH, ) # [Modified in Electra:EIP7251] max_effective_balance = get_max_effective_balance(validator) validator.effective_balance = min( amount - amount % EFFECTIVE_BALANCE_INCREMENT, max_effective_balance ) return validator ``` ###### Modified `add_validator_to_registry` *Note*: The function `add_validator_to_registry` is modified to use the modified `get_validator_from_deposit`. ```python def add_validator_to_registry( state: BeaconState, pubkey: BLSPubkey, withdrawal_credentials: Bytes32, amount: Gwei ) -> None: index = get_index_for_new_validator(state) # [Modified in Electra:EIP7251] validator = get_validator_from_deposit(pubkey, withdrawal_credentials, amount) set_or_append_list(state.validators, index, validator) set_or_append_list(state.balances, index, amount) set_or_append_list(state.previous_epoch_participation, index, ParticipationFlags(0b0000_0000)) set_or_append_list(state.current_epoch_participation, index, ParticipationFlags(0b0000_0000)) set_or_append_list(state.inactivity_scores, index, Uint64(0)) ``` ###### Modified `apply_deposit` *Note*: The function `apply_deposit` is modified to support EIP7251. ```python def apply_deposit( state: BeaconState, pubkey: BLSPubkey, withdrawal_credentials: Bytes32, amount: Gwei, signature: BLSSignature, ) -> None: validator_pubkeys = [validator.pubkey for validator in state.validators] if pubkey not in validator_pubkeys: # Verify the deposit signature (proof of possession) which is not checked by the deposit contract if is_valid_deposit_signature(pubkey, withdrawal_credentials, amount, signature): # [Modified in Electra:EIP7251] add_validator_to_registry(state, pubkey, withdrawal_credentials, Gwei(0)) else: return # [Modified in Electra:EIP7251] # Increase balance by deposit amount state.pending_deposits.append( PendingDeposit( pubkey=pubkey, withdrawal_credentials=withdrawal_credentials, amount=amount, signature=signature, slot=GENESIS_SLOT, # Use GENESIS_SLOT to distinguish from a pending deposit request ) ) ``` ###### New `is_valid_deposit_signature` ```python def is_valid_deposit_signature( pubkey: BLSPubkey, withdrawal_credentials: Bytes32, amount: Gwei, signature: BLSSignature ) -> bool: deposit_message = DepositMessage( pubkey=pubkey, withdrawal_credentials=withdrawal_credentials, amount=amount, ) # Fork-agnostic domain since deposits are valid across forks domain = compute_domain(DOMAIN_DEPOSIT) signing_root = compute_signing_root(deposit_message, domain) return bls.Verify(pubkey, signing_root, signature) ``` ###### Modified `process_deposit` *Note*: The function `process_deposit` is modified to use the modified `apply_deposit`. ```python def process_deposit(state: BeaconState, deposit: Deposit) -> None: # Verify the Merkle branch assert is_valid_merkle_branch( leaf=hash_tree_root(deposit.data), branch=deposit.proof, # Add 1 for the List length mix-in depth=DEPOSIT_CONTRACT_TREE_DEPTH + 1, index=state.eth1_deposit_index, root=state.eth1_data.deposit_root, ) # Deposits must be processed in order state.eth1_deposit_index += 1 # [Modified in Electra:EIP7251] apply_deposit( state=state, pubkey=deposit.data.pubkey, withdrawal_credentials=deposit.data.withdrawal_credentials, amount=deposit.data.amount, signature=deposit.data.signature, ) ``` ##### Voluntary exits ###### Modified `process_voluntary_exit` *Note*: The function `process_voluntary_exit` is modified to ensure the validator has no pending withdrawals in the queue. ```python def process_voluntary_exit(state: BeaconState, signed_voluntary_exit: SignedVoluntaryExit) -> None: voluntary_exit = signed_voluntary_exit.message validator = state.validators[voluntary_exit.validator_index] # Verify the validator is active assert is_active_validator(validator, get_current_epoch(state)) # Verify exit has not been initiated assert validator.exit_epoch == FAR_FUTURE_EPOCH # Exits must specify an epoch when they become valid; they are not valid before then assert get_current_epoch(state) >= voluntary_exit.epoch # Verify the validator has been active long enough assert get_current_epoch(state) >= validator.activation_epoch + SHARD_COMMITTEE_PERIOD # [New in Electra:EIP7251] # Only exit validator if it has no pending withdrawals in the queue assert get_pending_balance_to_withdraw(state, voluntary_exit.validator_index) == 0 # Verify signature domain = compute_domain( DOMAIN_VOLUNTARY_EXIT, CAPELLA_FORK_VERSION, state.genesis_validators_root ) signing_root = compute_signing_root(voluntary_exit, domain) assert bls.Verify(validator.pubkey, signing_root, signed_voluntary_exit.signature) # Initiate exit initiate_validator_exit(state, voluntary_exit.validator_index) ``` ##### Execution-layer withdrawal requests ###### New `process_withdrawal_request` ```python def process_withdrawal_request(state: BeaconState, withdrawal_request: WithdrawalRequest) -> None: amount = withdrawal_request.amount is_full_exit_request = amount == FULL_EXIT_REQUEST_AMOUNT # If partial withdrawal queue is full, only full exits are processed if ( len(state.pending_partial_withdrawals) == PENDING_PARTIAL_WITHDRAWALS_LIMIT and not is_full_exit_request ): return validator_pubkeys = [validator.pubkey for validator in state.validators] # Verify pubkey exists request_pubkey = withdrawal_request.validator_pubkey if request_pubkey not in validator_pubkeys: return index = ValidatorIndex(validator_pubkeys.index(request_pubkey)) validator = state.validators[index] # Verify withdrawal credentials has_correct_credential = has_execution_withdrawal_credential(validator) is_correct_source_address = ( validator.withdrawal_credentials[12:] == withdrawal_request.source_address ) if not (has_correct_credential and is_correct_source_address): return # Verify the validator is active if not is_active_validator(validator, get_current_epoch(state)): return # Verify exit has not been initiated if validator.exit_epoch != FAR_FUTURE_EPOCH: return # Verify the validator has been active long enough if get_current_epoch(state) < validator.activation_epoch + SHARD_COMMITTEE_PERIOD: return pending_balance_to_withdraw = get_pending_balance_to_withdraw(state, index) if is_full_exit_request: # Only exit validator if it has no pending withdrawals in the queue if pending_balance_to_withdraw == 0: initiate_validator_exit(state, index) return has_sufficient_effective_balance = validator.effective_balance >= MIN_ACTIVATION_BALANCE has_excess_balance = ( state.balances[index] > MIN_ACTIVATION_BALANCE + pending_balance_to_withdraw ) # Only allow partial withdrawals with compounding withdrawal credentials if ( has_compounding_withdrawal_credential(validator) and has_sufficient_effective_balance and has_excess_balance ): to_withdraw = min( state.balances[index] - MIN_ACTIVATION_BALANCE - pending_balance_to_withdraw, amount ) exit_queue_epoch = compute_exit_epoch_and_update_churn(state, to_withdraw) withdrawable_epoch = exit_queue_epoch + MIN_VALIDATOR_WITHDRAWABILITY_DELAY state.pending_partial_withdrawals.append( PendingPartialWithdrawal( validator_index=index, amount=to_withdraw, withdrawable_epoch=withdrawable_epoch, ) ) ``` ##### Deposit requests ###### New `process_deposit_request` ```python def process_deposit_request(state: BeaconState, deposit_request: DepositRequest) -> None: # Set deposit request start index if state.deposit_requests_start_index == UNSET_DEPOSIT_REQUESTS_START_INDEX: state.deposit_requests_start_index = deposit_request.index state.pending_deposits.append( PendingDeposit( pubkey=deposit_request.pubkey, withdrawal_credentials=deposit_request.withdrawal_credentials, amount=deposit_request.amount, signature=deposit_request.signature, slot=state.slot, ) ) ``` ##### Execution-layer consolidation requests ###### New `is_valid_switch_to_compounding_request` ```python def is_valid_switch_to_compounding_request( state: BeaconState, consolidation_request: ConsolidationRequest ) -> bool: # Switch to compounding requires source and target be equal if consolidation_request.source_pubkey != consolidation_request.target_pubkey: return False # Verify pubkey exists source_pubkey = consolidation_request.source_pubkey validator_pubkeys = [validator.pubkey for validator in state.validators] if source_pubkey not in validator_pubkeys: return False source_validator = state.validators[ValidatorIndex(validator_pubkeys.index(source_pubkey))] # Verify request has been authorized if source_validator.withdrawal_credentials[12:] != consolidation_request.source_address: return False # Verify source withdrawal credentials if not has_eth1_withdrawal_credential(source_validator): return False # Verify the source is active current_epoch = get_current_epoch(state) if not is_active_validator(source_validator, current_epoch): return False # Verify exit for source has not been initiated if source_validator.exit_epoch != FAR_FUTURE_EPOCH: return False return True ``` ###### New `process_consolidation_request` ```python def process_consolidation_request( state: BeaconState, consolidation_request: ConsolidationRequest ) -> None: if is_valid_switch_to_compounding_request(state, consolidation_request): validator_pubkeys = [validator.pubkey for validator in state.validators] request_source_pubkey = consolidation_request.source_pubkey source_index = ValidatorIndex(validator_pubkeys.index(request_source_pubkey)) switch_to_compounding_validator(state, source_index) return # Verify that source != target, so a consolidation cannot be used as an exit if consolidation_request.source_pubkey == consolidation_request.target_pubkey: return # If the pending consolidations queue is full, consolidation requests are ignored if len(state.pending_consolidations) == PENDING_CONSOLIDATIONS_LIMIT: return # If there is too little available consolidation churn limit, consolidation requests are ignored if get_consolidation_churn_limit(state) <= MIN_ACTIVATION_BALANCE: return validator_pubkeys = [validator.pubkey for validator in state.validators] # Verify pubkeys exists request_source_pubkey = consolidation_request.source_pubkey request_target_pubkey = consolidation_request.target_pubkey if request_source_pubkey not in validator_pubkeys: return if request_target_pubkey not in validator_pubkeys: return source_index = ValidatorIndex(validator_pubkeys.index(request_source_pubkey)) target_index = ValidatorIndex(validator_pubkeys.index(request_target_pubkey)) source_validator = state.validators[source_index] target_validator = state.validators[target_index] # Verify source withdrawal credentials has_correct_credential = has_execution_withdrawal_credential(source_validator) is_correct_source_address = ( source_validator.withdrawal_credentials[12:] == consolidation_request.source_address ) if not (has_correct_credential and is_correct_source_address): return # Verify that target has compounding withdrawal credentials if not has_compounding_withdrawal_credential(target_validator): return # Verify the source and the target are active current_epoch = get_current_epoch(state) if not is_active_validator(source_validator, current_epoch): return if not is_active_validator(target_validator, current_epoch): return # Verify exits for source and target have not been initiated if source_validator.exit_epoch != FAR_FUTURE_EPOCH: return if target_validator.exit_epoch != FAR_FUTURE_EPOCH: return # Verify the source has been active long enough if current_epoch < source_validator.activation_epoch + SHARD_COMMITTEE_PERIOD: return # Verify the source has no pending withdrawals in the queue if get_pending_balance_to_withdraw(state, source_index) > 0: return # Initiate source validator exit and append pending consolidation source_validator.exit_epoch = compute_consolidation_epoch_and_update_churn( state, source_validator.effective_balance ) source_validator.withdrawable_epoch = ( source_validator.exit_epoch + MIN_VALIDATOR_WITHDRAWABILITY_DELAY ) state.pending_consolidations.append( PendingConsolidation(source_index=source_index, target_index=target_index) ) ```