diff --git a/wwwroot/api/workspace_tree.dspy b/wwwroot/api/workspace_tree.dspy
index f0f7ad0..9018d1c 100644
--- a/wwwroot/api/workspace_tree.dspy
+++ b/wwwroot/api/workspace_tree.dspy
@@ -1,4 +1,8 @@
-# workspace_tree.dspy - 只返回目录树，不含文件
+# workspace_tree.dspy - 返回目录子节点（支持 id 参数做懒加载）
+
+import os
+
+node_id = (params_kw or {}).get('id', '').strip()
 
 uid = await get_user()
 if not uid:
@@ -6,7 +10,6 @@ if not uid:
 
 dbname = get_module_dbname('pipeline-sdlc')
 workspace_base = '/d/pipeline/workspaces'
-import os
 
 async with DBPools().sqlorContext(dbname) as sor:
     recs = await sor.sqlExe(
@@ -26,29 +29,50 @@ async with DBPools().sqlorContext(dbname) as sor:
             ws_dir = ws if ws.startswith('/') else workspace_base + '/' + org_id + '/' + pname
 
 if not ws_dir or not os.path.isdir(ws_dir):
-    return [{"id": "__root__", "parentid": "", "label": "📁 工作空间（不可用）", "path": ""}]
+    if not node_id or node_id == '__root__':
+        return [{"id": "__root__", "parentid": "", "label": "📁 工作空间（不可用）", "path": "", "is_leaf": False}]
+    return []
 
-items = [{"id": "__root__", "parentid": "", "label": "📁 " + os.path.basename(ws_dir), "path": ws_dir, "is_leaf": False}]
+# 确定要扫描的目录
+if not node_id or node_id == '__root__':
+    # 初始加载：返回根节点
+    return [{
+        "id": "__root__",
+        "parentid": "",
+        "label": "📁 " + os.path.basename(ws_dir),
+        "path": ws_dir,
+        "is_leaf": False
+    }]
 
-def scan_dir(path, parent_id, rel_prefix):
-    try:
-        entries = sorted(os.listdir(path))
-    except Exception:
-        return
-    for name in entries:
-        full = os.path.join(path, name)
-        if name.startswith('.') or name == '__pycache__':
-            continue
-        if os.path.isdir(full):
-            rel_path = rel_prefix + '/' + name if rel_prefix else name
-            items.append({
-                "id": rel_path,
-                "parentid": parent_id,
-                "label": "📁 " + name,
-                "path": full,
-                "is_leaf": False
-            })
-            scan_dir(full, rel_path, rel_path)
+# 展开节点：返回该目录的直接子目录
+if node_id == '__root__':
+    scan_path = ws_dir
+    rel_prefix = ""
+else:
+    scan_path = ws_dir + '/' + node_id
+    rel_prefix = node_id
+
+if not os.path.isdir(scan_path):
+    return []
+
+items = []
+try:
+    entries = sorted(os.listdir(scan_path))
+except Exception:
+    return []
+
+for name in entries:
+    full = os.path.join(scan_path, name)
+    if name.startswith('.') or name == '__pycache__':
+        continue
+    if os.path.isdir(full):
+        rel_path = rel_prefix + '/' + name if rel_prefix else name
+        items.append({
+            "id": rel_path,
+            "parentid": node_id,
+            "label": "📁 " + name,
+            "path": full,
+            "is_leaf": False
+        })
 
-scan_dir(ws_dir, "__root__", "")
 return items