diff --git a/tracers.ts/src/tracers/array-tracer.ts b/tracers.ts/src/tracers/array-tracer.ts
index 9a3bb4b..f705f13 100644
--- a/tracers.ts/src/tracers/array-tracer.ts
+++ b/tracers.ts/src/tracers/array-tracer.ts
@@ -1,44 +1,51 @@
 import { getTracerContext } from '../context';
 import type { JsonValue } from '../types';
 
-interface BaseArrayTracerCreateOptions {
+interface ArrayTracerCreateOptions<T extends JsonValue> {
   description?: string;
+  initial?: T[];
+  walker?: (builder: { add: (item: T) => void }) => void;
 }
 
-interface ArrayTracerCreateOptionsFromArray<
-  T extends JsonValue[],
-> extends BaseArrayTracerCreateOptions {
-  array: T;
-  walker?: never;
-}
+type ArrayTracerMetadata = {
+  // initial: JsonValue[];
+  length: number;
+};
 
-interface ArrayTracerCreateOptionsFromWalker<
-  T extends JsonValue[],
-> extends BaseArrayTracerCreateOptions {
-  array?: never;
-  walker: (commit: (item: T[number]) => void) => void;
-}
-
-type ArrayTracerCreateOptions<T extends JsonValue[]> =
-  | ArrayTracerCreateOptionsFromArray<T>
-  | ArrayTracerCreateOptionsFromWalker<T>;
-
-export const createArrayTracer = <T extends JsonValue[]>(
+export const createArrayTracer = <T extends JsonValue = JsonValue>(
   options: ArrayTracerCreateOptions<T>,
 ) => {
-  const { description, array, walker } = options;
+  const { description, initial, walker } = options;
   const tracer = crypto.randomUUID();
 
-  // 优化：仅维护数组长度作为影子状态，这在 C++/Java 等强类型语言中也极易实现（仅需一个 int 变量）
-  // 这种“最小必要状态”策略既能实现越界校验，又避免了在强类型语言中处理泛型存储的复杂性，且内存开销极低。
-  let arrayLength = array ? array.length : 0;
+  const metadata: ArrayTracerMetadata = {
+    length: 0,
+  };
+
+  const buildInitial = () => {
+    if (!!initial) {
+      return [...initial];
+    }
+    if (!!walker) {
+      const initial: T[] = [];
+      walker({
+        add: (item) => {
+          initial.push(item);
+        },
+      });
+      return initial;
+    }
+    return [];
+  };
+
+  // console.log(_initial);
 
   const { command } = getTracerContext();
 
   const validateIndex = (index: number) => {
-    if (index < 0 || index >= arrayLength) {
+    if (index < 0 || index >= metadata.length) {
       throw new Error(
-        `[ArrayTracer] Index out of bounds: index ${index} is not within [0, ${arrayLength})`,
+        `ArrayTracer: Index out of bounds: index ${index} is not within [0, ${metadata.length})`,
       );
     }
   };
@@ -47,18 +54,18 @@ export const createArrayTracer = <T extends JsonValue[]>(
     type: 'ArrayTracer',
     tracer: tracer,
     action: 'create',
-    params: {
+    payload: {
       description: description ?? 'ArrayTracer',
-      array: array ?? [],
+      initial: buildInitial(),
     },
   });
 
   // size 为正时，数组长度增加；为负时，数组长度减少（但不能小于 0）
   const scale = (size: number) => {
-    arrayLength += size;
-    if (arrayLength < 0) {
+    metadata.length += size;
+    if (metadata.length < 0) {
       throw new Error(
-        `[ArrayTracer] Invalid size: ${size}, array length cannot be negative`,
+        `ArrayTracer: Invalid size: ${size}, array length cannot be negative`,
       );
     }
 
@@ -66,7 +73,7 @@ export const createArrayTracer = <T extends JsonValue[]>(
       type: 'ArrayTracer',
       tracer: tracer,
       action: 'scale',
-      params: {
+      payload: {
         size: size,
       },
     });
@@ -79,7 +86,7 @@ export const createArrayTracer = <T extends JsonValue[]>(
       type: 'ArrayTracer',
       tracer: tracer,
       action: 'pick',
-      params: {
+      payload: {
         index: index,
       },
     });
@@ -92,20 +99,20 @@ export const createArrayTracer = <T extends JsonValue[]>(
       type: 'ArrayTracer',
       tracer: tracer,
       action: 'drop',
-      params: {
+      payload: {
         index: index,
       },
     });
   };
 
-  const patch = (index: number, value: T[number]) => {
+  const patch = (index: number, value: T) => {
     validateIndex(index);
 
     command({
       type: 'ArrayTracer',
       tracer: tracer,
       action: 'patch',
-      params: {
+      payload: {
         index: index,
         value: value,
       },
@@ -119,7 +126,7 @@ export const createArrayTracer = <T extends JsonValue[]>(
       type: 'ArrayTracer',
       tracer: tracer,
       action: 'unset',
-      params: {
+      payload: {
         index: index,
       },
     });
diff --git a/tracers.ts/src/types/array-tracer.ts b/tracers.ts/src/types/array-tracer.ts
index 81eb06e..78dc98f 100644
--- a/tracers.ts/src/types/array-tracer.ts
+++ b/tracers.ts/src/types/array-tracer.ts
@@ -6,36 +6,36 @@ type BaseArrayTracerCommand = BaseTracerCommand & {
 
 type ArrayTracerCreateCommand = BaseArrayTracerCommand & {
   action: 'create';
-  params: {
+  payload: {
     description: string;
-    array: JsonValue[];
+    initial: JsonValue[];
   };
 };
 
 type ArrayTracerScaleCommand = BaseArrayTracerCommand & {
   action: 'scale';
-  params: {
+  payload: {
     size: number;
   };
 };
 
 type ArrayTracerPickCommand = BaseArrayTracerCommand & {
   action: 'pick';
-  params: {
+  payload: {
     index: number;
   };
 };
 
 type ArrayTracerDropCommand = BaseArrayTracerCommand & {
   action: 'drop';
-  params: {
+  payload: {
     index: number;
   };
 };
 
 type ArrayTracerPatchCommand = BaseArrayTracerCommand & {
   action: 'patch';
-  params: {
+  payload: {
     index: number;
     value: JsonValue;
   };
@@ -43,7 +43,7 @@ type ArrayTracerPatchCommand = BaseArrayTracerCommand & {
 
 type ArrayTracerUnsetCommand = BaseArrayTracerCommand & {
   action: 'unset';
-  params: {
+  payload: {
     index: number;
   };
 };