diff --git a/public/locales/en.json b/public/locales/en.json
index fef1539..ea4938e 100644
--- a/public/locales/en.json
+++ b/public/locales/en.json
@@ -1,5 +1,6 @@
 {
   "about": "About Behavior3",
+  "add": "Add",
   "actuaSize": "Actual Size",
   "build": "Build",
   "batch": "Batch Script",
@@ -18,6 +19,7 @@
   "donotSave": "Don't Save",
   "duplicate": "Duplicate",
   "editSubtree": "Edit Subtree",
+  "fieldRequired": "Field '{{field}}' is required",
   "forceReload": "Force Reload",
   "fullscreen": "Toggle Full Screen",
   "hide": "Hide Behavior3",
@@ -77,6 +79,11 @@
   "tree.desc": "Tree desc",
   "tree.export": "Export",
   "tree.firstid": "First id",
+  "tree.vars": "Variable Definition",
+  "tree.vars.name": "name",
+  "tree.vars.invalidName": "Invalid variable name",
+  "tree.vars.desc": "description",
+  "tree.vars.imports": "Variable References",
 
   "regnode.input": "Input: ",
   "regnode.output": "Output: ",
@@ -85,9 +92,6 @@
   "regnode.subtree": "Subtree: ",
 
   "node.args": "Const arguments",
-  "node.args.add": "Add Sub Item",
-  "node.input.add": "Add Input Item",
-  "node.output.add": "Add Output Item",
   "node.children.unlimited": "Unlimited",
   "node.children": "Num children",
   "node.debug": "Debug",
@@ -95,7 +99,6 @@
   "node.desc": "Node desc",
   "node.disabled": "Disabled",
   "node.editSubtreeDenied": "Unable to edit the subtree node",
-  "node.fileRequired": "Field '{{field}}' is required",
   "node.id": "Node id",
   "node.inputVariable": "Input variables",
   "node.invalidValue": "Invalid value",
diff --git a/public/locales/zh.json b/public/locales/zh.json
index 4a6de34..dedb7b1 100644
--- a/public/locales/zh.json
+++ b/public/locales/zh.json
@@ -1,5 +1,6 @@
 {
   "about": "关于 Behavior3",
+  "add": "添加",
   "actualSize": "实际大小",
   "build": "构建",
   "batch": "批处理脚本",
@@ -18,6 +19,7 @@
   "donotSave": "不保存",
   "duplicate": "生成副本",
   "editSubtree": "编辑子树",
+  "fieldRequired": "字段“{{field}}”必填",
   "forceReload": "强制重新加载",
   "fullscreen": "切换全屏",
   "hide": "隐藏 Behavior3",
@@ -77,6 +79,11 @@
   "tree.desc": "说明",
   "tree.export": "导出",
   "tree.firstid": "起始标识",
+  "tree.vars": "变量定义",
+  "tree.vars.name": "变量名",
+  "tree.vars.invalidName": "变量名不合法",
+  "tree.vars.desc": "变量说明",
+  "tree.vars.imports": "变量引用",
 
   "regnode.input": "输入：",
   "regnode.output": "输出：",
@@ -85,9 +92,6 @@
   "regnode.subtree": "子树：",
 
   "node.args": "常量参数",
-  "node.args.add": "添加子项",
-  "node.input.add": "添加输入项",
-  "node.output.add": "添加输出项",
   "node.children.unlimited": "无限制",
   "node.children": "子节点数量",
   "node.debug": "调试",
@@ -95,7 +99,6 @@
   "node.desc": "节点说明",
   "node.disabled": "禁用",
   "node.editSubtreeDenied": "不能编辑子树节点",
-  "node.fileRequired": "字段“{{field}}”必填",
   "node.id": "节点标识",
   "node.inputVariable": "输入变量",
   "node.invalidValue": "无效的值",
diff --git a/sample/vars/declare-core.json b/sample/vars/declare-core.json
new file mode 100644
index 0000000..d139597
--- /dev/null
+++ b/sample/vars/declare-core.json
@@ -0,0 +1,23 @@
+{
+  "name": "def-core",
+  "desc": "",
+  "firstid": 1,
+  "export": true,
+  "declare": {
+    "imports": [],
+    "vars": [
+      {
+        "name": "context",
+        "desc": "上下文"
+      },
+      {
+        "name": "version",
+        "desc": "版本"
+      }
+    ]
+  },
+  "root": {
+    "id": 1,
+    "name": "Sequence"
+  }
+}
\ No newline at end of file
diff --git a/sample/vars/declare-vars.json b/sample/vars/declare-vars.json
new file mode 100644
index 0000000..2998f3b
--- /dev/null
+++ b/sample/vars/declare-vars.json
@@ -0,0 +1,25 @@
+{
+  "name": "declare-vars",
+  "desc": "",
+  "firstid": 1,
+  "export": true,
+  "declare": {
+    "imports": [
+      "vars/declare-core.json"
+    ],
+    "vars": [
+      {
+        "name": "owner",
+        "desc": "所有者"
+      },
+      {
+        "name": "skill",
+        "desc": "技能"
+      }
+    ]
+  },
+  "root": {
+    "id": 1,
+    "name": "Sequence"
+  }
+}
\ No newline at end of file
diff --git a/sample/vars/test-subtree.json b/sample/vars/test-subtree.json
new file mode 100644
index 0000000..77abdc5
--- /dev/null
+++ b/sample/vars/test-subtree.json
@@ -0,0 +1,23 @@
+{
+  "name": "test-subtree",
+  "desc": "",
+  "firstid": 1,
+  "export": true,
+  "declare": {
+    "imports": [],
+    "vars": []
+  },
+  "root": {
+    "id": 1,
+    "name": "Sequence",
+    "children": [
+      {
+        "id": 2,
+        "name": "Log",
+        "args": {
+          "message": "hello"
+        }
+      }
+    ]
+  }
+}
\ No newline at end of file
diff --git a/sample/vars/test-vars.json b/sample/vars/test-vars.json
new file mode 100644
index 0000000..78f4dae
--- /dev/null
+++ b/sample/vars/test-vars.json
@@ -0,0 +1,51 @@
+{
+  "name": "test-vars",
+  "desc": "",
+  "firstid": 1,
+  "export": true,
+  "declare": {
+    "imports": [
+      "vars/declare-core.json",
+      "vars/declare-vars.json"
+    ],
+    "vars": [
+      {
+        "name": "target",
+        "desc": "目标"
+      }
+    ]
+  },
+  "root": {
+    "id": 1,
+    "name": "Sequence",
+    "children": [
+      {
+        "id": 2,
+        "name": "Sequence",
+        "path": "vars/test-subtree.json"
+      },
+      {
+        "id": 4,
+        "name": "FindEnemy",
+        "args": {},
+        "output": [
+          "target"
+        ]
+      },
+      {
+        "id": 5,
+        "name": "Attack",
+        "input": [
+          "target"
+        ]
+      },
+      {
+        "id": 6,
+        "name": "Check",
+        "args": {
+          "value": "target.x > 0"
+        }
+      }
+    ]
+  }
+}
\ No newline at end of file
diff --git a/sample/workspace.b3-workspace b/sample/workspace.b3-workspace
index 577cdcc..be3beb0 100644
--- a/sample/workspace.b3-workspace
+++ b/sample/workspace.b3-workspace
@@ -1,5 +1,21 @@
 {
   "files": [
+    {
+      "path": "vars/declare-core.json",
+      "desc": ""
+    },
+    {
+      "path": "vars/declare-vars.json",
+      "desc": ""
+    },
+    {
+      "path": "vars/test-subtree.json",
+      "desc": ""
+    },
+    {
+      "path": "vars/test-vars.json",
+      "desc": ""
+    },
     {
       "path": "workdir/hero.json",
       "desc": "英雄测试AI"
diff --git a/src/components/editor.tsx b/src/components/editor.tsx
index 47fc4f1..ef6503d 100644
--- a/src/components/editor.tsx
+++ b/src/components/editor.tsx
@@ -464,6 +464,8 @@ export const Editor: FC<EditorProps> = ({ onUpdate: updateState, data: editor, .
       editor.export = editTree.data.export !== false;
       if (editor.data.firstid !== editTree.data.firstid) {
         editor.firstid = editTree.data.firstid ?? 1;
+        editor.declare.vars = editTree.data.declare.vars || [];
+        editor.declare.imports = editTree.data.declare.imports || [];
         refresh();
       }
       onChange();
@@ -1042,7 +1044,10 @@ export const Editor: FC<EditorProps> = ({ onUpdate: updateState, data: editor, .
   useKeyDown(Hotkey.Undo, keysRef, () => undo());
   useKeyDown(Hotkey.Redo, keysRef, () => redo());
   useKeyDown([Hotkey.Insert, Hotkey.Enter], keysRef, () => createNode());
-  useKeyDown([Hotkey.Delete, Hotkey.Backspace], keysRef, () => deleteNode());
+  useKeyDown([Hotkey.Delete, Hotkey.Backspace], keysRef, () => {
+    console.log("delete");
+    deleteNode();
+  });
 
   editor.dispatch = (event: EditEvent, data: unknown) => {
     switch (event) {
@@ -1055,6 +1060,7 @@ export const Editor: FC<EditorProps> = ({ onUpdate: updateState, data: editor, .
         break;
       }
       case "delete": {
+        console.log("delete1");
         deleteNode();
         break;
       }
@@ -1217,6 +1223,8 @@ export const Editor: FC<EditorProps> = ({ onUpdate: updateState, data: editor, .
     } else if ((e.ctrlKey || e.metaKey) && e.code === "KeyG") {
       searchByType("id");
     }
+    console.log(e.code);
+    e.stopPropagation();
   };
 
   const recursiveOpenCollapsed = (id: string) => {
@@ -1281,7 +1289,7 @@ export const Editor: FC<EditorProps> = ({ onUpdate: updateState, data: editor, .
               }
               onFocus={() => setFilterOption({ ...filterOption, isFocused: true })}
               onBlur={() => setFilterOption({ ...filterOption, isFocused: false })}
-              onKeyDown={handleKeyDown}
+              onKeyDownCapture={handleKeyDown}
               suffix={
                 <Flex gap="2px" style={{ alignItems: "center" }}>
                   {filterOption.filterType !== "id" && (
diff --git a/src/components/inspector.tsx b/src/components/inspector.tsx
index f29a96a..89c57f9 100644
--- a/src/components/inspector.tsx
+++ b/src/components/inspector.tsx
@@ -1,4 +1,4 @@
-import { EditOutlined, MinusCircleOutlined, PlusOutlined } from "@ant-design/icons";
+import { AimOutlined, EditOutlined, MinusCircleOutlined, PlusOutlined } from "@ant-design/icons";
 import {
   AutoComplete,
   Button,
@@ -8,6 +8,7 @@ import {
   Input,
   InputNumber,
   Select,
+  Space,
   Switch,
 } from "antd";
 import TextArea from "antd/es/input/TextArea";
@@ -19,6 +20,7 @@ import { useDebounceCallback } from "usehooks-ts";
 import { useShallow } from "zustand/react/shallow";
 import { EditNode, EditTree, useWorkspace } from "../contexts/workspace-context";
 import {
+  ImportDef,
   isBoolType,
   isEnumType,
   isExprType,
@@ -28,6 +30,7 @@ import {
   isStringType,
   NodeModel,
   TreeGraphData,
+  VarDef,
 } from "../misc/b3type";
 import {
   checkNodeArgValue,
@@ -37,6 +40,7 @@ import {
   isNodeArgOptional,
   isValidVariableName,
   isVariadic,
+  loadImportedVars,
 } from "../misc/b3util";
 import { Hotkey, isMacos } from "../misc/keys";
 import { mergeClassNames } from "../misc/util";
@@ -50,6 +54,9 @@ const TreeInspector: FC = () => {
     useShallow((state) => ({
       editing: state.editing,
       editingTree: state.editingTree!,
+      allFiles: state.allFiles,
+      relative: state.relative,
+      fileTree: state.fileTree,
     }))
   );
   const { t } = useTranslation();
@@ -58,13 +65,31 @@ const TreeInspector: FC = () => {
   // set form values
   useEffect(() => {
     const data = workspace.editingTree.data;
+    loadImportedVars(data.declare.imports);
     form.resetFields();
     form.setFieldValue("name", data.name);
     form.setFieldValue("desc", data.desc);
     form.setFieldValue("export", data.export !== false);
     form.setFieldValue("firstid", data.firstid);
+    form.setFieldValue("declare.vars", data.declare?.vars);
+    form.setFieldValue("declare.imports", data.declare?.imports);
   }, [workspace.editingTree]);
 
+  // auto complete for subtree
+  const subtreeOptions = useMemo(() => {
+    const options: OptionType[] = [];
+    workspace.allFiles.forEach((file) => {
+      const value = workspace.relative(file.path);
+      const desc = ""; //fileNode.desc ? `(${fileNode.desc})` : "";
+      options.push({
+        label: `${value}${desc}`,
+        value: value,
+      });
+    });
+    options.sort((a, b) => a.value.localeCompare(b.value));
+    return options;
+  }, [workspace.allFiles, workspace.fileTree]);
+
   const finish = (values: any) => {
     workspace.editing?.dispatch("updateTree", {
       data: {
@@ -72,6 +97,18 @@ const TreeInspector: FC = () => {
         desc: values.desc || undefined,
         export: values.export,
         firstid: Number(values.firstid),
+        declare: {
+          vars: (values["declare.vars"] as VarDef[])
+            .filter((v) => v && v.name)
+            .sort((a, b) => a.name.localeCompare(b.name)),
+          imports: (values["declare.imports"] as ImportDef[])
+            .filter((v) => v && v.path)
+            .sort((a, b) => a.path.localeCompare(b.path))
+            .map((v) => ({
+              path: v.path,
+              vars: v.vars ?? [],
+            })),
+        },
       },
     } as EditTree);
   };
@@ -85,19 +122,238 @@ const TreeInspector: FC = () => {
         className={mergeClassNames("b3-inspector-content", isMacos ? "" : "b3-overflow")}
         style={{ overflow: "auto", height: "100%" }}
       >
-        <Form form={form} labelCol={{ span: 8 }} onFinish={finish}>
-          <Form.Item name="name" label={t("tree.name")}>
-            <Input disabled={true} />
-          </Form.Item>
-          <Form.Item name="desc" label={t("tree.desc")}>
-            <TextArea autoSize onBlur={form.submit} />
-          </Form.Item>
-          <Form.Item name="firstid" label={t("tree.firstid")}>
-            <InputNumber min={1} onBlur={form.submit} />
-          </Form.Item>
-          <Form.Item name="export" label={t("tree.export")} valuePropName="checked">
-            <Switch onChange={() => form.submit()} />
-          </Form.Item>
+        <Form
+          form={form}
+          wrapperCol={{ span: "auto" }}
+          labelCol={{ span: "auto" }}
+          onFinish={finish}
+        >
+          <>
+            <Form.Item name="name" label={t("tree.name")}>
+              <Input disabled={true} />
+            </Form.Item>
+            <Form.Item name="desc" label={t("tree.desc")}>
+              <TextArea autoSize onBlur={form.submit} />
+            </Form.Item>
+            <Form.Item name="firstid" label={t("tree.firstid")}>
+              <InputNumber min={1} onBlur={form.submit} />
+            </Form.Item>
+            <Form.Item name="export" label={t("tree.export")} valuePropName="checked">
+              <Switch onChange={() => form.submit()} />
+            </Form.Item>
+          </>
+          <>
+            <Divider orientation="left">
+              <h4>{t("tree.vars")}</h4>
+            </Divider>
+            <Form.List name="declare.vars">
+              {(items, { add, remove }, { errors }) => (
+                <div style={{ display: "flex", flexDirection: "column", rowGap: 0 }}>
+                  {items.map((item) => (
+                    <Flex key={item.key} gap={4}>
+                      <Space.Compact
+                        className="b3-inspector-vars-item"
+                        style={{ width: "100%", marginBottom: 2 }}
+                      >
+                        <Form.Item
+                          noStyle
+                          name={[item.name, "name"]}
+                          validateTrigger={["onChange", "onBlur"]}
+                          rules={[
+                            {
+                              validator(_, value) {
+                                if (value && /^[_\w]+\w*$/.test(value)) {
+                                  return Promise.resolve();
+                                }
+                                return Promise.reject(new Error(t("tree.vars.invalidName")));
+                              },
+                            },
+                          ]}
+                        >
+                          <Input
+                            addonBefore={
+                              <div style={{ display: "flex", alignItems: "center", width: "45px" }}>
+                                <AimOutlined />
+                                <span style={{ marginLeft: 4 }}>0</span>
+                              </div>
+                            }
+                            placeholder={t("tree.vars.name")}
+                            onBlur={form.submit}
+                          />
+                        </Form.Item>
+                        <Form.Item
+                          noStyle
+                          name={[item.name, "desc"]}
+                          validateTrigger={["onChange", "onBlur"]}
+                          rules={[
+                            {
+                              required: true,
+                              message: t("fieldRequired", { field: t("tree.vars.desc") }),
+                            },
+                          ]}
+                        >
+                          <Input
+                            style={{ width: "75%" }}
+                            placeholder={t("tree.vars.desc")}
+                            onBlur={form.submit}
+                          />
+                        </Form.Item>
+                      </Space.Compact>
+                      <MinusCircleOutlined
+                        style={{ marginBottom: "6px" }}
+                        onClick={() => {
+                          remove(item.name);
+                          form.submit();
+                        }}
+                      />
+                    </Flex>
+                  ))}
+                  <Form.Item
+                    style={{
+                      marginRight: items.length === 0 ? undefined : "18px",
+                      marginTop: 4,
+                      alignItems: "end",
+                    }}
+                  >
+                    <Button
+                      type="dashed"
+                      onClick={() => {
+                        add({});
+                      }}
+                      style={{ width: "100%" }}
+                      icon={<PlusOutlined />}
+                    >
+                      {t("add")}
+                    </Button>
+                    <Form.ErrorList errors={errors} />
+                  </Form.Item>
+                </div>
+              )}
+            </Form.List>
+          </>
+          <>
+            <Divider orientation="left">
+              <h4>{t("tree.vars.imports")}</h4>
+            </Divider>
+            <Form.List name="declare.imports">
+              {(items, { add, remove }, { errors }) => (
+                <div style={{ display: "flex", flexDirection: "column", rowGap: 4 }}>
+                  {items.map((item) => (
+                    <Space.Compact
+                      key={item.key}
+                      className="b3-inspector-import-item"
+                      direction="vertical"
+                      style={{ marginBottom: 5 }}
+                    >
+                      <Flex gap={4} style={{ width: "100%" }}>
+                        <Form.Item
+                          name={[item.name, "path"]}
+                          style={{ width: "100%", marginBottom: 2 }}
+                        >
+                          <Select
+                            showSearch
+                            options={subtreeOptions}
+                            onBlur={form.submit}
+                            onInputKeyDown={(e) => e.code === Hotkey.Escape && e.preventDefault()}
+                            filterOption={(value, option) => {
+                              const label = option!.label as string;
+                              return label.toUpperCase().includes(value.toUpperCase());
+                            }}
+                          />
+                        </Form.Item>
+                        <MinusCircleOutlined
+                          style={{ marginBottom: "6px" }}
+                          onClick={() => {
+                            remove(item.name);
+                            form.submit();
+                          }}
+                        />
+                      </Flex>
+                      <Form.List name={[item.name, "vars"]}>
+                        {(vars) => (
+                          <div style={{ display: "flex", flexDirection: "column", rowGap: 0 }}>
+                            {vars.map((v, idx, arr) => (
+                              <Flex key={v.key} gap={4}>
+                                <Space.Compact
+                                  className="b3-inspector-vars-item"
+                                  style={{ width: "100%", marginBottom: 0, paddingRight: 18 }}
+                                >
+                                  <Form.Item noStyle name={[v.name, "id"]}>
+                                    <div
+                                      style={{
+                                        display: "flex",
+                                        alignItems: "center",
+                                        paddingLeft: "8px",
+                                        paddingRight: "8px",
+                                        maxWidth: "60px",
+                                        minWidth: "60px",
+                                        borderTopLeftRadius: idx === 0 ? "4px" : 0,
+                                        borderBottomLeftRadius: idx === arr.length - 1 ? "4px" : 0,
+                                        borderLeft: "1px solid #3d506c",
+                                        borderTop: "1px solid #3d506c",
+                                        borderBottom:
+                                          idx === arr.length - 1 ? "1px solid #3d506c" : "none",
+                                      }}
+                                    >
+                                      <AimOutlined />
+                                      <span style={{ marginLeft: 4 }}>0</span>
+                                    </div>
+                                  </Form.Item>
+                                  <Form.Item noStyle name={[v.name, "name"]}>
+                                    <Input
+                                      disabled={true}
+                                      placeholder={t("tree.vars.name")}
+                                      style={{
+                                        borderRadius: "0",
+                                        borderTop: "1px solid #3d506c",
+                                        borderBottom:
+                                          idx === arr.length - 1 ? "1px solid #3d506c" : "none",
+                                      }}
+                                    />
+                                  </Form.Item>
+                                  <Form.Item noStyle name={[v.name, "desc"]}>
+                                    <Input
+                                      disabled={true}
+                                      placeholder={t("tree.vars.desc")}
+                                      style={{
+                                        borderTopRightRadius: idx === 0 ? "4px" : 0,
+                                        borderBottomRightRadius: idx === arr.length - 1 ? "4px" : 0,
+                                        borderTop: "1px solid #3d506c",
+                                        borderBottom:
+                                          idx === arr.length - 1 ? "1px solid #3d506c" : "none",
+                                      }}
+                                    />
+                                  </Form.Item>
+                                </Space.Compact>
+                              </Flex>
+                            ))}
+                          </div>
+                        )}
+                      </Form.List>
+                    </Space.Compact>
+                  ))}
+                  <Form.Item
+                    style={{
+                      marginRight: items.length === 0 ? undefined : "18px",
+                      alignItems: "end",
+                    }}
+                  >
+                    <Button
+                      type="dashed"
+                      onClick={() => {
+                        add({});
+                      }}
+                      style={{ width: "100%" }}
+                      icon={<PlusOutlined />}
+                    >
+                      {t("add")}
+                    </Button>
+                    <Form.ErrorList errors={errors} />
+                  </Form.Item>
+                </div>
+              )}
+            </Form.List>
+          </>
         </Form>
       </div>
     </>
@@ -490,7 +746,7 @@ const NodeInspector: FC = () => {
                                 style={{ width: fields.length === 0 ? "100%" : "200px" }}
                                 icon={<PlusOutlined />}
                               >
-                                {t("node.input.add")}
+                                {t("add")}
                               </Button>
                               <Form.ErrorList errors={errors} />
                             </Form.Item>
@@ -506,7 +762,7 @@ const NodeInspector: FC = () => {
                       name={`input.${i}`}
                       key={`input.${i}`}
                       rules={[
-                        { required, message: t("node.fileRequired", { field: desc }) },
+                        { required, message: t("fieldRequired", { field: desc }) },
                         ({ getFieldValue, setFieldValue, isFieldValidating, validateFields }) => ({
                           validator(_, value) {
                             if (value && !isValidVariableName(value)) {
@@ -548,7 +804,7 @@ const NodeInspector: FC = () => {
                         onInputKeyDown={(e) => e.code === Hotkey.Escape && e.preventDefault()}
                         filterOption={(inputValue: string, option?: OptionType) => {
                           const label = option!.label as string;
-                          return label.toUpperCase().indexOf(inputValue.toUpperCase()) !== -1;
+                          return label.toUpperCase().includes(inputValue.toUpperCase());
                         }}
                       />
                     </Form.Item>
@@ -585,7 +841,7 @@ const NodeInspector: FC = () => {
                                   rules={[
                                     {
                                       required,
-                                      message: t("node.fileRequired", { field: arg.desc }),
+                                      message: t("fieldRequired", { field: arg.desc }),
                                     },
                                     () => ({
                                       validator(_, value) {
@@ -681,7 +937,7 @@ const NodeInspector: FC = () => {
                                 icon={<PlusOutlined />}
                                 danger={items.length === 0 && !isNodeArgOptional(arg)}
                               >
-                                {t("node.args.add")}
+                                {t("add")}
                               </Button>
                               <Form.ErrorList errors={errors} />
                             </Form.Item>
@@ -699,7 +955,7 @@ const NodeInspector: FC = () => {
                       initialValue={isBoolType(type) ? arg.default ?? false : arg.default}
                       valuePropName={isBoolType(type) ? "checked" : undefined}
                       rules={[
-                        { required, message: t("node.fileRequired", { field: arg.desc }) },
+                        { required, message: t("fieldRequired", { field: arg.desc }) },
                         ({ getFieldValue, setFieldValue, isFieldValidating, validateFields }) => ({
                           validator(_, value) {
                             if (value && isJsonType(type)) {
@@ -861,7 +1117,7 @@ const NodeInspector: FC = () => {
                                 style={{ width: fields.length === 0 ? "100%" : "200px" }}
                                 icon={<PlusOutlined />}
                               >
-                                {t("node.output.add")}
+                                {t("add")}
                               </Button>
                               <Form.ErrorList errors={errors} />
                             </Form.Item>
@@ -877,7 +1133,7 @@ const NodeInspector: FC = () => {
                       name={`output.${i}`}
                       key={`output.${i}`}
                       rules={[
-                        { required, message: t("node.fileRequired", { field: desc }) },
+                        { required, message: t("fieldRequired", { field: desc }) },
                         {
                           validator(_, value) {
                             if (value && !isValidVariableName(value)) {
diff --git a/src/contexts/workspace-context.ts b/src/contexts/workspace-context.ts
index 4e04220..79ac53e 100644
--- a/src/contexts/workspace-context.ts
+++ b/src/contexts/workspace-context.ts
@@ -5,7 +5,7 @@ import * as fs from "fs";
 import React from "react";
 import { create } from "zustand";
 import { NodeDef } from "../behavior3/src/behavior3";
-import { NodeModel, TreeGraphData, TreeModel, VarDef } from "../misc/b3type";
+import { ImportDef, NodeModel, TreeGraphData, TreeModel, VarDef } from "../misc/b3type";
 import * as b3util from "../misc/b3util";
 import { message } from "../misc/hooks";
 import i18n from "../misc/i18n";
@@ -50,10 +50,7 @@ export class EditorStore {
   firstid: number;
 
   declare: {
-    imports: {
-      path: string;
-      vars: VarDef[];
-    }[];
+    imports: ImportDef[];
     vars: VarDef[];
   };
 
@@ -122,7 +119,16 @@ export type EditNodeDef = {
 };
 
 export type EditTree = {
-  data: TreeModel;
+  data: {
+    name: string;
+    desc?: string;
+    export?: boolean;
+    firstid?: number;
+    declare: {
+      imports: ImportDef[];
+      vars: VarDef[];
+    };
+  };
 };
 
 export type FileMeta = {
@@ -511,7 +517,10 @@ export const useWorkspace = create<WorkspaceStore>((set, get) => ({
             name: editting.name,
             desc: editting.desc,
             firstid: editting.firstid,
-            root: null!,
+            declare: {
+              vars: editting.declare.vars,
+              imports: editting.declare.imports,
+            },
           },
         },
       });
@@ -666,7 +675,10 @@ export const useWorkspace = create<WorkspaceStore>((set, get) => ({
           desc: editor.desc,
           export: editor.export,
           firstid: editor.firstid,
-          root: null!,
+          declare: {
+            imports: editor.declare.imports,
+            vars: editor.declare.vars,
+          },
         },
       },
       editingNodeDef: null,
diff --git a/src/index.scss b/src/index.scss
index 45ce63e..d50a5b5 100644
--- a/src/index.scss
+++ b/src/index.scss
@@ -124,6 +124,11 @@ body {
   text-align: end;
 }
 
+.b3-inspector-vars-item .ant-input-group-addon {
+  padding-left: 8px;
+  padding-right: 8px;
+}
+
 :focus {
   outline: none;
 }
diff --git a/src/misc/b3type.ts b/src/misc/b3type.ts
index 469a367..2c93b4b 100644
--- a/src/misc/b3type.ts
+++ b/src/misc/b3type.ts
@@ -30,6 +30,12 @@ export interface VarDef {
   desc: string;
 }
 
+export interface ImportDef {
+  path: string;
+  date?: number;
+  vars: VarDef[];
+}
+
 export interface TreeModel {
   name: string;
   desc?: string;
diff --git a/src/misc/b3util.ts b/src/misc/b3util.ts
index d63d09c..6addaf4 100644
--- a/src/misc/b3util.ts
+++ b/src/misc/b3util.ts
@@ -1,6 +1,7 @@
 import * as fs from "fs";
-import { NodeDef } from "../behavior3/src/behavior3";
+import { type NodeDef } from "../behavior3/src/behavior3";
 import {
+  ImportDef,
   isBoolType,
   isEnumType,
   isExprType,
@@ -12,9 +13,10 @@ import {
   NodeModel,
   TreeGraphData,
   TreeModel,
+  VarDef,
 } from "./b3type";
 import Path from "./path";
-import { readJson } from "./util";
+import { readJson, readTree } from "./util";
 
 export class NodeDefs extends Map<string, NodeDef> {
   get(key: string): NodeDef {
@@ -603,8 +605,7 @@ export const createTreeData = (
     parsingStack.push(node.path);
     try {
       const subtreePath = workdir + "/" + node.path;
-      const str = fs.readFileSync(subtreePath, "utf8");
-      treeData = createTreeData(JSON.parse(str).root, treeData.id, calcSize);
+      treeData = createTreeData(readTree(subtreePath).root, treeData.id, calcSize);
       treeData.lastModified = fs.statSync(subtreePath).mtimeMs;
       treeData.path = node.path;
       treeData.debug = node.debug;
@@ -685,3 +686,36 @@ export const createNewTree = (path: string) => {
 export const isTreeFile = (path: string) => {
   return path.toLocaleLowerCase().endsWith(".json");
 };
+
+export const loadImportedVars = (imports: ImportDef[]) => {
+  for (const importDef of imports) {
+    // TODO: check file date
+    // TODO: use cache
+    if (importDef.vars.length) {
+      continue;
+    }
+    const filter: Map<string, boolean> = new Map();
+    const vars: VarDef[] = [];
+    const load = (path: string) => {
+      if (filter.has(path)) {
+        return;
+      }
+      filter.set(path, true);
+      const model: TreeModel = readTree(`${workdir}/${path}`);
+      model.declare?.vars?.forEach((v) => vars.push(v));
+      model.declare?.imports?.forEach((v) => load(v));
+      console.log("load imported vars:", path);
+    };
+    load(importDef.path);
+    filter.clear();
+    importDef.vars = vars
+      .filter((v) => {
+        if (!filter.has(v.name)) {
+          filter.set(v.name, true);
+          return true;
+        }
+        return false;
+      })
+      .sort((a, b) => a.name.localeCompare(b.name));
+  }
+};
diff --git a/src/misc/util.ts b/src/misc/util.ts
index 9c0f21a..eace039 100644
--- a/src/misc/util.ts
+++ b/src/misc/util.ts
@@ -1,10 +1,16 @@
 import * as fs from "fs";
+import type { TreeModel } from "./b3type";
 
 export const readJson = (path: string) => {
   const str = fs.readFileSync(path, "utf-8");
   return JSON.parse(str);
 };
 
+export const readTree = (path: string) => {
+  const str = fs.readFileSync(path, "utf-8");
+  return JSON.parse(str) as TreeModel;
+};
+
 export const writeJson = (path: string, data: any) => {
   const str = JSON.stringify(data, undefined, 2);
   fs.writeFileSync(path, str, "utf-8");