diff --git a/agent/canvas.py b/agent/canvas.py
index 3ad8c06c1..572b68e5c 100644
--- a/agent/canvas.py
+++ b/agent/canvas.py
@@ -154,7 +154,7 @@ class Graph:
         return self._tenant_id
 
     def get_value_with_variable(self,value: str) -> Any:
-        pat = re.compile(r"\{* *\{([a-zA-Z:0-9]+@[A-Za-z:0-9_.-]+|sys\.[a-z_]+)\} *\}*")
+        pat = re.compile(r"\{* *\{([a-zA-Z:0-9]+@[A-Za-z0-9_.]+|sys\.[A-Za-z0-9_.]+|env\.[A-Za-z0-9_.]+)\} *\}*")
         out_parts = []
         last = 0
 
@@ -256,18 +256,19 @@ class Canvas(Graph):
             self.retrieval = []
             self.memory = []
         for k in self.globals.keys():
-            if isinstance(self.globals[k], str):
-                self.globals[k] = ""
-            elif isinstance(self.globals[k], int):
-                self.globals[k] = 0
-            elif isinstance(self.globals[k], float):
-                self.globals[k] = 0
-            elif isinstance(self.globals[k], list):
-                self.globals[k] = []
-            elif isinstance(self.globals[k], dict):
-                self.globals[k] = {}
-            else:
-                self.globals[k] = None
+            if k.startswith("sys."):
+                if isinstance(self.globals[k], str):
+                    self.globals[k] = ""
+                elif isinstance(self.globals[k], int):
+                    self.globals[k] = 0
+                elif isinstance(self.globals[k], float):
+                    self.globals[k] = 0
+                elif isinstance(self.globals[k], list):
+                    self.globals[k] = []
+                elif isinstance(self.globals[k], dict):
+                    self.globals[k] = {}
+                else:
+                    self.globals[k] = None
 
     def run(self, **kwargs):
         st = time.perf_counter()
diff --git a/agent/component/base.py b/agent/component/base.py
index 75cb63abe..cfec4ac1f 100644
--- a/agent/component/base.py
+++ b/agent/component/base.py
@@ -393,7 +393,7 @@ class ComponentParamBase(ABC):
 class ComponentBase(ABC):
     component_name: str
     thread_limiter = trio.CapacityLimiter(int(os.environ.get('MAX_CONCURRENT_CHATS', 10)))
-    variable_ref_patt = r"\{* *\{([a-zA-Z:0-9]+@[A-Za-z:0-9_.-]+|sys\.[a-z_]+)\} *\}*"
+    variable_ref_patt = r"\{* *\{([a-zA-Z:0-9]+@[A-Za-z0-9_.]+|sys\.[A-Za-z0-9_.]+|env\.[A-Za-z0-9_.]+)\} *\}*"
 
     def __str__(self):
         """
diff --git a/agent/component/message.py b/agent/component/message.py
index 6fcedf984..1a506325e 100644
--- a/agent/component/message.py
+++ b/agent/component/message.py
@@ -99,7 +99,7 @@ class Message(ComponentBase):
                 continue
 
             v = self._canvas.get_variable_value(exp)
-            if not v:
+            if v is None:
                 v = ""
             if isinstance(v, partial):
                 cnt = ""
@@ -107,7 +107,7 @@ class Message(ComponentBase):
                     all_content += t
                     cnt += t
                     yield t
-
+                self.set_input_value(exp, cnt)
                 continue
             elif not isinstance(v, str):
                 try:
@@ -115,6 +115,7 @@ class Message(ComponentBase):
                 except Exception:
                     v = str(v)
             yield v
+            self.set_input_value(exp, v)
             all_content += v
             cache[exp] = v
 
diff --git a/agent/tools/retrieval.py b/agent/tools/retrieval.py
index cd6435271..77b6145ed 100644
--- a/agent/tools/retrieval.py
+++ b/agent/tools/retrieval.py
@@ -135,7 +135,7 @@ class Retrieval(ToolBase, ABC):
             elif self._param.meta_data_filter.get("method") == "manual":
                 filters=self._param.meta_data_filter["manual"]
                 for flt in filters:
-                    pat = re.compile(r"\{* *\{([a-zA-Z:0-9]+@[A-Za-z:0-9_.-]+|sys\.[a-z_]+)\} *\}*")
+                    pat = re.compile(self.variable_ref_patt)
                     s = flt["value"]
                     out_parts = []
                     last = 0
diff --git a/docker/entrypoint.sh b/docker/entrypoint.sh
index f470fa6c1..f24d5baac 100755
--- a/docker/entrypoint.sh
+++ b/docker/entrypoint.sh
@@ -187,7 +187,7 @@ function start_mcp_server() {
 }
 
 function ensure_docling() {
-    [[ "${USE_DOCLING}" == "true" ]] || return 0
+    [[ "${USE_DOCLING}" == "true" ]] || { echo "[docling] disabled by USE_DOCLING"; return 0; }
     python3 -c 'import pip' >/dev/null 2>&1 || python3 -m ensurepip --upgrade || true
     DOCLING_PIN="${DOCLING_VERSION:-==2.58.0}"
     python3 -c "import importlib.util,sys; sys.exit(0 if importlib.util.find_spec('docling') else 1)" \