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VEX

Witness Log

VEX Witness pillarexecution provenancetool call record

The Witness Log is the VEX Protocol's execution record pillar — a granular, tamper-evident log of every tool invocation and result.

THE ACCOUNTABILITY GAP WITHOUT WITNESS LOGS

AI agents without structured logging produce outcomes without a verifiable decision chain. Post-incident investigation is reduced to speculation. Witness logs provide a verifiable reconstruction.

PROTOCOL CONTEXT (VEX — WITNESS PILLAR)

The Witness pillar specifies the schema for per-action witness records: tool name, invocation timestamp, parameter hash, and result hash. Records are Merkle-linked for chain-of-custody integrity.

ProvnAI Mitigation

McpVanguard automatically generates Witness Log entries for every tool call. All records are anchored to the Merkle Audit Trail. The Provn SDK provides WitnessQuery APIs for structured retrieval.