postmortem

# Postmortem > **Purpose:** Answer an explicit retrospective causal question using the > already-validated outcome and evidence. ## Prompt ```text Postmortem: verdict .agents/ao/verdicts/2026-08-30-cli-regen.json shows NOT_PROVEN then PASS after we added a mutating-check guard to skills/validate/scripts/validate.sh. Did that guard actually cause the fix, or did the flaky CI runner just stop flaking that day? ``` ## It's working if Observable in the trace, without reading the prose: - The report pins the exact `verdict.v2` id and the causal question before the timeline section. - A claim promoted to cause cites its mechanism, evidence, and counterfactual together under the report's `hypotheses` list. - A claim resting only on symptom cessation is listed under `unknowns`, not promoted to cause. - The report lands at `.agents/scratch/postmortem/YYYY-MM-DD-postmortem-<topic>.md` and `bash skills/postmortem/scripts/validate.sh` exits 0. ## Critical Constraints - Because proof and causal inference are different judgments, Postmortem is retrospective causal analysis, not the general learning umbrella and not a completion gate. - It consumes immutable Validate verdict evidence and does not re-run acceptance validation because Validate already owns that proof. - Treat causal statements as hypotheses because causal confidence must survive alternatives. Separate observed sequence, contributing conditions, counterfactuals, and unknowns. - A correlation is not promot...