diff --git a/agent-ui/.sync-state.json b/agent-ui/.sync-state.json
new file mode 100644
index 0000000..4c7e9af
--- /dev/null
+++ b/agent-ui/.sync-state.json
@@ -0,0 +1,14 @@
+{
+  "last_synced_head": "b5a1d1a4ef663f0b68795a1f3c45381c78460df2",
+  "last_sync_mode": "baseline",
+  "baseline_mode": "migration",
+  "agent_ui_paths": [
+    "agent-ui/README.md",
+    "agent-ui/definition/index.md",
+    "agent-ui/definition/views/",
+    "agent-ui/definition/components/",
+    "agent-ui/frame/index.md"
+  ],
+  "code_paths": [],
+  "notes": "Legacy agent-ui baseline migration. No code sync performed."
+}