diff --git a/demo/.env.example b/demo/.env.example
index 5bd69f2..4c5f5f6 100644
--- a/demo/.env.example
+++ b/demo/.env.example
@@ -16,3 +16,7 @@ REDIS_PASSWORD=
 # ── Environment ───────────────────────────────────────────────────────────────
 # Keep as "production" (hides /docs, enforces security headers).
 ENVIRONMENT=production
+
+# ── Demo mode ─────────────────────────────────────────────────────────────────
+# Must be true for auto-seeding, hourly reset, and demo UI to work.
+DEMO_MODE=true