Anchor agent memory to artifacts, not prose: claim memory beat notes in all seven environments at p=0.0156 and never fabricated

arXiv 2608.04278·medium signalXBlueskyLinkedInCopy link

EA-Graph stores verification claims anchored to specific artifacts at sub-path granularity, tracking evidence strength separately from freshness, and marks a claim unprovable rather than fabricating when the underlying content is gone. Across 42 sessions in seven environments the artifact-anchored condition beat both prose notes and no persistent memory on Haiku in all seven worlds (each exact paired Wilcoxon p=0.0156); Sonnet hit the control ceiling. The builder takeaway is that structured claim memory narrows model capability gaps by making re-derivation cheap — the failure mode of prose handoff notes is preserving a conclusion without the state that justified it.