Implement FOCIL (EIP-7805) for Grandine

[Subhasish-Behera]

Implement FOCIL (EIP-7805)

Spec: EIP-7805 - Fork-Choice enforced Inclusion Lists

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Overview

Implement Fork-Choice enforced Inclusion Lists (FOCIL) to enable censorship resistance through committee-based forced transaction inclusion.

Resources

Specification:

• beacon-chain.md
• fork-choice.md
• fork.md
• inclusion-list.md
• p2p-interface.md
• validator.md

Engine API :

• ethereum/execution-apis src/engine/experimental/eip7805.md - engine_getInclusionListV1, engine_newPayloadV5, engine_forkchoiceUpdatedV4

Beacon API :

• ethereum/beacon-APIs apis/validator/inclusion_list.yaml, apis/validator/duties/inclusion_list.yaml - IL duties, produce/publish IL, event stream

Additional:

• FOCIL Proposal

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Checklist

Types & Core Containers

• Container Types (InclusionList, SignedInclusionList) - beacon-chain.md#new-containers
• Fix transaction list sizing to use MAX_TRANSACTIONS_PER_PAYLOAD - beacon-chain.md#inclusionlist
• Configuration constants (DOMAIN_INCLUSION_LIST_COMMITTEE, etc.) - beacon-chain.md#constants, beacon-chain.md#preset
• Fork activation config - fork.md#configuration

Storage

• Create InclusionListStore - inclusion-list.md#inclusionliststore
• Implement InclusionListManager - inclusion-list.md#new-get_inclusion_list_store
• Equivocation tracking - inclusion-list.md#new-process_inclusion_list
• Integrate into Controller
• IL pruning logic

Fork Choice

• Add Store.unsatisfied_inclusion_list_blocks - fork-choice.md#modified-store
• Implement validate_inclusion_lists - fork-choice.md#new-validate_inclusion_lists
• Call validate_inclusion_lists in on_block - fork-choice.md#modified-on_block
• Implement get_attester_head - fork-choice.md#new-get_attester_head
• Modify get_proposer_head - fork-choice.md#modified-get_proposer_head
• Modify proposer boost logic - fork-choice.md#modified-on_block
• Fork choice tests

Engine API

• Implement is_inclusion_list_satisfied (engine_newPayloadV5) - execution-apis eip7805.md#engine_newpayloadv5, fork-choice.md#new-is_inclusion_list_satisfied
• Implement engine_getInclusionListV1 - execution-apis eip7805.md#engine_getinclusionlistv1
• Implement is_inclusion_list_satisfied in Eth1Api - execution-apis eip7805.md#engine_newpayloadv5
• Modify notify_forkchoice_updated (engine_forkchoiceUpdatedV4) - execution-apis eip7805.md#engine_forkchoiceupdatedv4, fork-choice.md#modified-notify_forkchoice_updated

Note: Two approaches exist for applying ILs to payload building:

• Approach A: Call FCU with empty IL at slot start, then call FCU again with actual IL once gathered (requires EL to support updating in-flight payload via FCU)
• Approach B: Call FCU once, then use engine_updatePayloadWithInclusionListV1 to inject IL into in-flight payload

Approach A uses engine_forkchoiceUpdatedV4. Approach B is an alternative if EL doesn't support mid-build FCU updates.

Gossip & P2P

• P2P message types - p2p-interface.md#topics-and-messages
• Gossip publication - p2p-interface.md#inclusion_list
• Gossip reception routing - p2p-interface.md#inclusion_list
• Gossip validation logic - p2p-interface.md#inclusion_list
• Signature verification - beacon-chain.md#new-is_valid_inclusion_list_signature
• RPC protocol (req/resp) - p2p-interface.md#inclusionlistbycommitteeindices-v1
• Event stream API

Validator Duties

• Beacon state accessors (get_inclusion_list_committee) - beacon-chain.md#new-get_inclusion_list_committee, validator.md#inclusion-list-committee
• OwnILCommitteeMembers tracker
• IL duty scheduling - validator.md#time-parameters
• IL publishing logic - validator.md#constructing-the-signedinclusionlist
• Update attester duty - validator.md#modified-lmd-ghost-vote

Beacon REST API

• GET /eth/v1/validator/inclusion_list - Produce IL - beacon-APIs inclusion_list.yaml
• POST /eth/v1/validator/inclusion_list - Publish IL - beacon-APIs inclusion_list.yaml
• POST /eth/v1/validator/duties/inclusion_list/{epoch} - Get IL committee duties - beacon-APIs duties/inclusion_list.yaml
• Event stream: inclusion_list event - beacon-APIs eventstream/index.yaml

Block Production

• Freeze IL view at cutoff - validator.md#time-parameters, validator.md#executionpayload
• Include ILs in payload attributes - validator.md#executionpayload, fork-choice.md#modified-payloadattributes