diff --git a/diagnostic/server.js b/diagnostic/server.js
index dc83d8b..dbf69a2 100644
--- a/diagnostic/server.js
+++ b/diagnostic/server.js
@@ -1582,10 +1582,11 @@ async function handleListSessions(clientWs) {
       for f in ${SESSIONS_DIR}/*.jsonl; do
         [ -f "$f" ] || continue
         name=$(basename "$f")
-        lines=$(wc -l < "$f" 2>/dev/null || echo 0)
+        # Nur echte User/Assistant Messages zaehlen — nicht Tool-Calls, Events etc.
+        msgs=$(grep -cE '"role":"(user|assistant)"' "$f" 2>/dev/null || echo 0)
         size=$(du -h "$f" 2>/dev/null | cut -f1)
         modified=$(stat -c '%Y' "$f" 2>/dev/null || echo 0)
-        echo "FILE:$name|LINES:$lines|SIZE:$size|MODIFIED:$modified"
+        echo "FILE:$name|LINES:$msgs|SIZE:$size|MODIFIED:$modified"
       done
     `.trim());