Two October 30 revisions to Ethereum's EIP-8148 draft change how a validator's custom sweep threshold would be stored and specify the request format for updating it. The later commit, recorded at 11:21:52 UTC, replaces a proposed separate state mapping with a two-byte field inside compounding withdrawal credentials.
EIP-8148 remains a Draft Core proposal. The repository edits change its specification; they do not establish a network deployment or activation date.
Threshold storage moves into credentials
The revised layout assigns bytes 1 and 2 of a validator's 0x02 withdrawal credentials to a little-endian uint16 threshold, measured in EFFECTIVE_BALANCE_INCREMENT units. Byte 0 retains the credential prefix, and bytes 12 through 31 retain the execution address. No new field would be added to BeaconState or Validator.
Zero encodes the default maximum threshold. Out-of-range values are read as the default, and the proposed fork transition would clear the two bytes for existing validators. The document's rationale favors using spare credential bytes over maintaining a separate per-validator list.
This changes what applications can infer from comparing credentials. The revised compatibility section tells applications that compare all 32 bytes, including EIP-4788 proof verifiers, to compare the prefix and execution address instead. Updating the threshold would change credential bytes without changing that address.
Contract input and request encoding differ
The earlier commit, at 11:13:25 UTC, specifies a 56-byte contract input: a 48-byte validator public key followed by an eight-byte big-endian threshold in Gwei. It also specifies a 76-byte anonymous log containing the caller's address, public key and threshold. The outgoing execution request uses little-endian threshold encoding, so the formats are not interchangeable.
The optional custom-threshold feature was already described in September coverage. These revisions concern its proposed storage and integration details. The reviewed draft still leaves the contract deployment address as TBD.
Earlier coverage of this event: EIP-8148 Author Details Sweep-Threshold Revisions for Ethereum Validators.