diff --git a/website/docs/user-guide/sessions.md b/website/docs/user-guide/sessions.md
index 5b8d70245c..32389d862b 100644
--- a/website/docs/user-guide/sessions.md
+++ b/website/docs/user-guide/sessions.md
@@ -376,6 +376,8 @@ hermes sessions export backup.jsonl --redact
 
 Exported files contain one JSON object per line with full session metadata and all messages.
 
+Each record also carries a `timings` block derived from the message timestamps, so a reader of an export attached to a bug report can tell a single long model gap from many small tool round-trips without reconstructing it by hand. It holds only ids, roles, counts and durations — `wall_clock_ms`, `largest_gap_ms`, `role_counts`, `tool_calls_emitted` and per-message `intervals` — never prompt text, tool arguments or results, so it survives `--redact` unchanged. Hermes does not persist a model/tool stopwatch, so `complete` is always `false`; when a session has no timestamped messages, `available` is `false` and `unavailable_reason` says why. The block is rebuilt on every export and ignored (and not counted toward size limits) on import.
+
 #### HTML
 
 `--format html` writes a single self-contained HTML file — no remote dependencies — with styled message bubbles, collapsible tool output, and (for multi-session exports) a sidebar to switch between sessions: