diff --git a/src/routes/demo.py b/src/routes/demo.py
index d60a28c..ee764c9 100644
--- a/src/routes/demo.py
+++ b/src/routes/demo.py
@@ -72,16 +72,24 @@ def _ctx(request: Request, extra: dict) -> dict:
 
 
 def _logger(sess: dict):
-    """Returns a callback that appends log entries to sess['api_log']."""
+    """Returns a callback that appends log entries to server-side store (not cookie)."""
     def cb(entry: dict):
-        log = sess.setdefault("api_log", [])
+        sid = sess.get("sid", "")
+        if not sid:
+            return
+        store = _token_store.setdefault(sid, {})
+        log = store.setdefault("api_log", [])
         log.append(entry)
-        # keep last 50 entries
         if len(log) > 50:
-            sess["api_log"] = log[-50:]
+            store["api_log"] = log[-50:]
     return cb
 
 
+def _get_api_log(sess: dict) -> list:
+    sid = sess.get("sid", "")
+    return _token_store.get(sid, {}).get("api_log", [])
+
+
 # ---------------------------------------------------------------------------
 # Landing
 # ---------------------------------------------------------------------------
@@ -111,7 +119,7 @@ async def debug_session(request: Request):
         for k, v in sess.items()
         if k != "api_log"
     }
-    safe["api_log_count"] = len(sess.get("api_log", []))
+    safe["api_log_count"] = len(_get_api_log(sess))
     safe["cookie_size_bytes"] = len(str(request.session))
     return safe
 
@@ -627,7 +635,7 @@ async def step6(request: Request):
 @router.get("/demo/log", response_class=HTMLResponse)
 async def api_log(request: Request):
     sess = _session(request)
-    log = sess.get("api_log", [])
+    log = _get_api_log(sess)
     return templates.TemplateResponse("log.html", _ctx(request, {
         "log": list(reversed(log)),  # newest first
         "log_count": len(log),
@@ -637,7 +645,9 @@ async def api_log(request: Request):
 @router.post("/demo/log/clear")
 async def clear_log(request: Request):
     sess = _session(request)
-    sess["api_log"] = []
+    sid = sess.get("sid", "")
+    if sid and sid in _token_store:
+        _token_store[sid].pop("api_log", None)
     return RedirectResponse("/demo/log", status_code=303)