Ethereum's proposal repository added EIP-8247, “Ancestor-Indexed BALs,” on October 9, publishing a draft that would replace repeated addresses and storage keys in block access lists with references to recent blocks. The proposal builds on the block access list structures defined by EIP-7928.
The merge is a publication milestone for an existing proposal. Author Toni Wahrstätter created the draft and opened its pull request on May 3. Its current status remains Draft, and it describes a consensus change requiring a hard fork.
Block access lists record accounts and storage locations involved in a block. Under EIP-8247, an address already present in a recent ancestor list would be represented by the ancestor's offset and the account's position. A storage-key reference adds the slot's position within that account's dictionary. This replaces repeated identifiers, while other access-list fields and semantics remain unchanged.
The reference window covers the previous eight canonical blocks after activation. A reference must point to an ancestor's expanded, validated list, rather than its encoded representation. References to the current block or blocks before activation are invalid.
The draft also makes reference selection deterministic. When a valid reference exists, a producer must use it instead of repeating the literal value. Where several references match, the specified ordering chooses the smallest one. Clients would need to retain or reconstruct the recent expanded lists and their storage-slot dictionaries to apply these rules.
Validation then expands the references and applies EIP-7928's existing checks. The access-list item count is calculated on that expanded data, rather than treating a shorter reference as fewer accessed items.
The proposal's test-case section remains marked TBD. Repository publication does not establish client implementation, network scheduling or mainnet activation. Its concrete contribution is an encoding and validation design for implementers to review, with additional recent-block data requirements. No measured performance result accompanies this merge.