ERC-8329 Subject-Linked Impact Snapshot Log

ReviewERCcreated 2026-07-05requires ERC-165

Defines append-only subject-linked impact snapshots with correction provenance, methodology versioning, and attestations

Authors: Chris Turner, David Hay (@david-hay), Reagan Simpson (@krumg111), Collins Musyimi (@Musyimi97)

ERC-165 interface ids

Computed here as the XOR of the selectors each interface defines.

`0x14b679e1`	`activeMethodology(bytes32,bytes32)`	view
`0x9deab8e4`	`attestationCount(bytes32,uint256)`	view
`0xede1ef89`	`attestSnapshot(bytes32,uint256,bool,bytes32,string)`
`0x32f2212e`	`currentSnapshotForPeriod(bytes32,bytes32,uint64,uint64)`	view
`0xeac3b277`	`getAttestation(bytes32,uint256,uint256)`	view
`0x3df3ce14`	`getSnapshot(bytes32,uint256)`	view
`0x444061d4`	`indicatorSnapshotAt(bytes32,bytes32,uint256)`	view
`0x4c1d2201`	`indicatorSnapshotCount(bytes32,bytes32)`	view
`0x75793efd`	`latestIndicatorSnapshot(bytes32,bytes32)`	view
`0x2e68488d`	`pendingMethodology(bytes32,bytes32)`	view
`0xec171469`	`recordSnapshot(bytes32,bytes32,int256,uint8,bytes32,uint64,uint64,bytes32,string,uint256)`
`0x52c6a722`	`snapshotCount(bytes32)`	view
`0x46e2fc33`	`supersedeMethodology(bytes32,bytes32,bytes32,bytes32,string,uint256)`

Topic0 is the keccak256 hash of the signature, which is what a log filter matches on.

`0xb9b096868ddc36f431a577bdb40be65735e8a998e4724c4b8bb84847b9028dcb`	`SnapshotRecorded(bytes32,bytes32,uint256,int256,uint8,bytes32,uint64,uint64,bytes32,uint256,address)`
`0xd907a545f6e9bcd113677383260d484b9d601ae6f593c59eb56bfb9e07da8fbb`	`SnapshotAttested(bytes32,uint256,address,bool,bytes32,uint256)`
`0x48858c432f9fd5f69bb0e29997f78b3381e7e5e88e627c0ef7e52dbd740568d0`	`MethodologySuperseded(bytes32,bytes32,bytes32,bytes32,uint256)`