diff --git a/pipeline_platform/platform_ability.py b/pipeline_platform/platform_ability.py
index c5dc4ff..3bdc8ae 100644
--- a/pipeline_platform/platform_ability.py
+++ b/pipeline_platform/platform_ability.py
@@ -1168,12 +1168,12 @@ def _resp_tpl_for(capability, spec):
         field = _MEDIA_OUT_FIELD.get(outkey, 'result_url')
         note = ('产物字段名「%s」按供应商惯例兜底（文档未提供响应示例或示例中无 URL 字段），'
                 '如上游字段不同需修正' % field)
-    resp = json.dumps({
-        'status': 'SUCCEEDED',
-        outkey: '{{ downloadfile2url(request, %s) }}' % field,
-        'usage': '{{ json.dumps(usage) }}',
-        'task_id': '{{ task_id }}',
-    }, ensure_ascii=False)
+    # usage 值不加包裹引号（2026-09-06 实测 bug）：`"usage": "{{ json.dumps(usage) }}"`
+    # 在 usage 非空时内层双引号破坏外层 JSON 字符串值 → json.loads 断在 char 161，
+    # 渲染整体回退、生成物不落地。渲染为嵌套 JSON 对象才是合法形态，手工拼接：
+    resp = ('{"status": "SUCCEEDED", "%s": "{{ downloadfile2url(request, %s) }}", '
+            '"usage": {{ json.dumps(usage) }}, "task_id": "{{ task_id }}"}'
+            % (outkey, field))
     return resp, note