fix(workflow): use loose rendering for end-node variables

api/app/core/workflow/nodes/base_node.py

@@ -259,7 +259,8 @@ class BaseNode(ABC):
             # Determine chunk type: "message" for End and adjacent nodes, "node_chunk" for others
             chunk_type = "message" if (is_end_node or is_adjacent_to_end) else "node_chunk"
 
-            logger.debug(f"节点 {self.node_id} chunk 类型: {chunk_type} (is_end={is_end_node}, adjacent={is_adjacent_to_end})")
+            logger.debug(
+                f"节点 {self.node_id} chunk 类型: {chunk_type} (is_end={is_end_node}, adjacent={is_adjacent_to_end})")
 
             # Accumulate complete result (for final wrapping)
             chunks = []
@@ -534,7 +535,7 @@ class BaseNode(ABC):
                 return edge
         return None
 
-    def _render_template(self, template: str, state: WorkflowState | None, struct: bool = True) -> str:
+    def _render_template(self, template: str, state: WorkflowState | None, strict: bool = True) -> str:
         """渲染模板
         
         支持的变量命名空间：
@@ -569,7 +570,7 @@ class BaseNode(ABC):
             variables=variables,
             node_outputs=pool.get_all_node_outputs(),
             system_vars=pool.get_all_system_vars(),
-            struct=struct
+            strict=strict
         )
 
     def _evaluate_condition(self, expression: str, state: WorkflowState | None) -> bool:

api/app/core/workflow/nodes/end/node.py

@@ -37,7 +37,7 @@ class EndNode(BaseNode):
 
         # 如果配置了输出模板，使用模板渲染；否则使用默认输出
         if output_template:
-            output = self._render_template(output_template, state, struct=False)
+            output = self._render_template(output_template, state, strict=False)
         else:
             output = "工作流已完成"
 
@@ -156,6 +156,16 @@ class EndNode(BaseNode):
 
         if not output_template:
             output = "工作流已完成"
+            from langgraph.config import get_stream_writer
+            writer = get_stream_writer()
+            writer({
+                "type": "message",  # End node output uses message type
+                "node_id": self.node_id,
+                "chunk": "",
+                "full_content": output,
+                "chunk_index": 1,
+                "is_suffix": False
+            })
             yield {"__final__": True, "result": output}
             return
 
@@ -190,7 +200,7 @@ class EndNode(BaseNode):
 
         if upstream_llm_ref_index is None:
             # No reference to direct upstream LLM node, output complete template content
-            output = self._render_template(output_template, state)
+            output = self._render_template(output_template, state, strict=False)
             logger.info(f"节点 {self.node_id} 没有引用直接上游 LLM 节点，输出完整内容: '{output[:50]}...'")
 
             # Send complete content via writer (as a single message chunk)
@@ -246,7 +256,7 @@ class EndNode(BaseNode):
         suffix = "".join(suffix_parts)
 
         # 构建完整输出（用于返回，包含前缀 + 动态内容 + 后缀）
-        full_output = self._render_template(output_template, state)
+        full_output = self._render_template(output_template, state, strict=False)
 
         logger.info(f"[后缀调试] 节点 {self.node_id} 后缀部分数量: {len(suffix_parts)}")
         logger.info(f"[后缀调试] 后缀内容: '{suffix}'")

api/app/core/workflow/template_renderer.py

@@ -5,6 +5,7 @@
 """
 
 import logging
+from collections import defaultdict
 from typing import Any
 
 from jinja2 import TemplateSyntaxError, UndefinedError, Environment, StrictUndefined, Undefined
@@ -12,6 +13,18 @@ from jinja2 import TemplateSyntaxError, UndefinedError, Environment, StrictUndef
 logger = logging.getLogger(__name__)
 
 
+class SafeUndefined(Undefined):
+    """访问未定义属性不会报错，返回空字符串"""
+    __slots__ = ()
+
+    def _fail_with_undefined_error(self, *args, **kwargs):
+        return ""
+
+    __add__ = __radd__ = __mul__ = __rmul__ = __div__ = __rdiv__ = __truediv__ = __rtruediv__ = _fail_with_undefined_error
+    __getitem__ = __getattr__ = _fail_with_undefined_error
+    __str__ = __repr__ = lambda self: ""
+
+
 class TemplateRenderer:
     """模板渲染器"""
 
@@ -21,8 +34,9 @@ class TemplateRenderer:
         Args:
             strict: 是否使用严格模式（未定义变量会抛出异常）
         """
+        self.strict = strict
         self.env = Environment(
-            undefined=StrictUndefined if strict else Undefined,
+            undefined=StrictUndefined if strict else SafeUndefined,
             autoescape=False  # 不自动转义，因为我们处理的是文本而非 HTML
         )
 
@@ -69,7 +83,12 @@ class TemplateRenderer:
         # variables 的结构：{"sys": {...}, "conv": {...}}
         sys_vars = variables.get("sys", {}) if isinstance(variables, dict) else {}
         conv_vars = variables.get("conv", {}) if isinstance(variables, dict) else {}
-
+        if self.strict:
+            context = defaultdict(dict)
+            context["conv"] = conv_vars
+            context["nodes"] = node_outputs
+            context["sys"] = {**(system_vars or {}), **sys_vars}
+        else:
             context = {
                 "conv": conv_vars,  # 会话变量：{{conv.user_name}}
                 "node": node_outputs,  # 节点输出：{{node.node_1.output}}
@@ -141,12 +160,12 @@ def render_template(
         variables: dict[str, Any],
         node_outputs: dict[str, Any],
         system_vars: dict[str, Any] | None = None,
-        struct: bool = True
+        strict: bool = True
 ) -> str:
     """渲染模板（便捷函数）
     
     Args:
-        struct: 渲染模式
+        strict: 严格模式
         template: 模板字符串
         variables: 用户变量
         node_outputs: 节点输出
@@ -164,7 +183,7 @@ def render_template(
         ... )
         '请分析: 这是一段文本'
     """
-    renderer = TemplateRenderer(strict=struct)
+    renderer = TemplateRenderer(strict=strict)
     return renderer.render(template, variables, node_outputs, system_vars)
 
 

api/app/templates/workflows/simple_qa/template.yml

@@ -53,7 +53,7 @@ nodes:
     type: end
     name: 结束
     config:
-      output: "{{llm_qa.output}}"
+      output: "{{ llm_qa.output }}"
     position:
       x: 900
       y: 100