diff --git a/src/core/errors/__tests__/exception-handler.test.ts b/src/core/errors/__tests__/exception-handler.test.ts
new file mode 100644
index 00000000..50e83dd9
--- /dev/null
+++ b/src/core/errors/__tests__/exception-handler.test.ts
@@ -0,0 +1,104 @@
+import { describe, expect, it } from "vitest";
+import { z } from "zod";
+
+import { ApiError, ErrorCode } from "@/data/services/api/api_result";
+
+import { AppException } from "../app-exception";
+import { ExceptionCode } from "../exception-code";
+import { ExceptionHandler } from "../exception-handler";
+
+describe("ExceptionHandler", () => {
+  it("maps API status errors to stable user messages", () => {
+    expect(
+      ExceptionHandler.handle(
+        new ApiError("HTTP_UNAUTHORIZED", "raw backend message", 401),
+      ),
+    ).toEqual({
+      code: ExceptionCode.unauthorized,
+      message: "Session expired, please sign in again.",
+    });
+
+    expect(
+      ExceptionHandler.handle(
+        new ApiError("HTTP_SERVER_ERROR", "internal", 500),
+      ),
+    ).toEqual({
+      code: ExceptionCode.server,
+      message: "Server error, please try again later.",
+    });
+  });
+
+  it("maps known API codes without status", () => {
+    expect(
+      ExceptionHandler.handle(
+        new ApiError(ErrorCode.timeoutError, "request timeout"),
+      ),
+    ).toEqual({
+      code: ExceptionCode.timeout,
+      message: "request timeout",
+    });
+  });
+
+  it("maps network and cancellation errors", () => {
+    expect(ExceptionHandler.handle(new TypeError("Failed to fetch"))).toEqual({
+      code: ExceptionCode.network,
+      message: "Network connection failed.",
+    });
+
+    expect(ExceptionHandler.handle(new DOMException("Aborted", "AbortError"))).toEqual({
+      code: ExceptionCode.cancelled,
+      message: "Request cancelled.",
+    });
+  });
+
+  it("maps schema and syntax errors to validation errors", () => {
+    const parseResult = z.object({ name: z.string() }).safeParse({ name: null });
+    if (parseResult.success) throw new Error("Expected parse failure");
+
+    expect(ExceptionHandler.handle(parseResult.error)).toEqual({
+      code: ExceptionCode.validation,
+      message: "Data format changed unexpectedly. Please try again.",
+    });
+
+    expect(ExceptionHandler.handle(new SyntaxError("Unexpected token"))).toEqual({
+      code: ExceptionCode.validation,
+      message: "Data format changed unexpectedly. Please try again.",
+    });
+  });
+
+  it("maps storage and payment errors", () => {
+    expect(ExceptionHandler.handle(new Error("localStorage unavailable"))).toEqual({
+      code: ExceptionCode.storage,
+      message: "Local data could not be saved. Please try again.",
+    });
+
+    expect(ExceptionHandler.handle(new Error("Stripe payment failed"))).toEqual({
+      code: ExceptionCode.payment,
+      message: "Payment could not be completed. Please try again.",
+    });
+  });
+
+  it("preserves an existing AppException result", () => {
+    const error = new AppException({
+      code: ExceptionCode.notFound,
+      message: "Custom not found",
+    });
+
+    expect(ExceptionHandler.handle(error)).toEqual({
+      code: ExceptionCode.notFound,
+      message: "Custom not found",
+    });
+  });
+
+  it("falls back to a simple message", () => {
+    expect(ExceptionHandler.handle("plain failure")).toEqual({
+      code: ExceptionCode.unknown,
+      message: "plain failure",
+    });
+
+    expect(ExceptionHandler.handle({ nope: true })).toEqual({
+      code: ExceptionCode.unknown,
+      message: "Something went wrong. Please try again.",
+    });
+  });
+});
diff --git a/src/core/errors/app-exception.ts b/src/core/errors/app-exception.ts
new file mode 100644
index 00000000..6865a276
--- /dev/null
+++ b/src/core/errors/app-exception.ts
@@ -0,0 +1,21 @@
+import type { ExceptionResult } from "./exception-result";
+import type { ExceptionCode } from "./exception-code";
+
+export class AppException extends Error {
+  readonly code: ExceptionCode;
+  override readonly cause?: unknown;
+
+  constructor(result: ExceptionResult, cause?: unknown) {
+    super(result.message);
+    this.name = "AppException";
+    this.code = result.code;
+    this.cause = cause;
+  }
+
+  toResult(): ExceptionResult {
+    return {
+      code: this.code,
+      message: this.message,
+    };
+  }
+}
diff --git a/src/core/errors/exception-code.ts b/src/core/errors/exception-code.ts
new file mode 100644
index 00000000..c0bd732c
--- /dev/null
+++ b/src/core/errors/exception-code.ts
@@ -0,0 +1,16 @@
+export const ExceptionCode = {
+  unknown: "UNKNOWN",
+  network: "NETWORK_ERROR",
+  timeout: "NETWORK_TIMEOUT",
+  unauthorized: "HTTP_UNAUTHORIZED",
+  forbidden: "HTTP_FORBIDDEN",
+  notFound: "HTTP_NOT_FOUND",
+  server: "HTTP_SERVER_ERROR",
+  validation: "VALIDATION_ERROR",
+  storage: "STORAGE_ERROR",
+  payment: "PAYMENT_ERROR",
+  cancelled: "CANCELLED",
+} as const;
+
+export type ExceptionCode =
+  (typeof ExceptionCode)[keyof typeof ExceptionCode];
diff --git a/src/core/errors/exception-handler.ts b/src/core/errors/exception-handler.ts
new file mode 100644
index 00000000..5748c667
--- /dev/null
+++ b/src/core/errors/exception-handler.ts
@@ -0,0 +1,47 @@
+import { AppException } from "./app-exception";
+import type { ExceptionResult } from "./exception-result";
+import { ApiExceptionHandler } from "./handlers/api-exception-handler";
+import { FallbackExceptionHandler } from "./handlers/fallback-exception-handler";
+import { NetworkExceptionHandler } from "./handlers/network-exception-handler";
+import { PaymentExceptionHandler } from "./handlers/payment-exception-handler";
+import { StorageExceptionHandler } from "./handlers/storage-exception-handler";
+import { ValidationExceptionHandler } from "./handlers/validation-exception-handler";
+
+export class ExceptionHandler {
+  static handle(error: unknown): ExceptionResult {
+    if (error instanceof AppException) {
+      return error.toResult();
+    }
+
+    if (ApiExceptionHandler.canHandle(error)) {
+      return ApiExceptionHandler.handle(error);
+    }
+
+    if (NetworkExceptionHandler.canHandle(error)) {
+      return NetworkExceptionHandler.handle(error);
+    }
+
+    if (ValidationExceptionHandler.canHandle(error)) {
+      return ValidationExceptionHandler.handle(error);
+    }
+
+    if (StorageExceptionHandler.canHandle(error)) {
+      return StorageExceptionHandler.handle(error);
+    }
+
+    if (PaymentExceptionHandler.canHandle(error)) {
+      return PaymentExceptionHandler.handle(error);
+    }
+
+    return FallbackExceptionHandler.handle(error);
+  }
+
+  static message(error: unknown): string {
+    return ExceptionHandler.handle(error).message;
+  }
+
+  static toError(error: unknown): AppException {
+    if (error instanceof AppException) return error;
+    return new AppException(ExceptionHandler.handle(error), error);
+  }
+}
diff --git a/src/core/errors/exception-result.ts b/src/core/errors/exception-result.ts
new file mode 100644
index 00000000..a07e1096
--- /dev/null
+++ b/src/core/errors/exception-result.ts
@@ -0,0 +1,6 @@
+import type { ExceptionCode } from "./exception-code";
+
+export interface ExceptionResult {
+  code: ExceptionCode;
+  message: string;
+}
diff --git a/src/core/errors/handlers/api-exception-handler.ts b/src/core/errors/handlers/api-exception-handler.ts
new file mode 100644
index 00000000..f24875d1
--- /dev/null
+++ b/src/core/errors/handlers/api-exception-handler.ts
@@ -0,0 +1,57 @@
+import { ApiError, ErrorCode } from "@/data/services/api/api_result";
+
+import { ExceptionCode } from "../exception-code";
+import type { ExceptionResult } from "../exception-result";
+
+export class ApiExceptionHandler {
+  static canHandle(error: unknown): error is ApiError {
+    return error instanceof ApiError;
+  }
+
+  static handle(error: ApiError): ExceptionResult {
+    switch (error.status) {
+      case ErrorCode.httpUnauthorized:
+        return {
+          code: ExceptionCode.unauthorized,
+          message: "Session expired, please sign in again.",
+        };
+      case ErrorCode.httpForbidden:
+        return {
+          code: ExceptionCode.forbidden,
+          message: "Access denied.",
+        };
+      case ErrorCode.httpNotFound:
+        return {
+          code: ExceptionCode.notFound,
+          message: "Resource not found.",
+        };
+      case ErrorCode.httpServerError:
+        return {
+          code: ExceptionCode.server,
+          message: "Server error, please try again later.",
+        };
+      default:
+        return {
+          code: mapApiCode(error.code),
+          message: error.message || "API call failed.",
+        };
+    }
+  }
+}
+
+function mapApiCode(code: string): ExceptionResult["code"] {
+  switch (code) {
+    case "HTTP_UNAUTHORIZED":
+      return ExceptionCode.unauthorized;
+    case "HTTP_SERVER_ERROR":
+      return ExceptionCode.server;
+    case ErrorCode.networkError:
+      return ExceptionCode.network;
+    case ErrorCode.timeoutError:
+      return ExceptionCode.timeout;
+    case ErrorCode.parseError:
+      return ExceptionCode.validation;
+    default:
+      return ExceptionCode.unknown;
+  }
+}
diff --git a/src/core/errors/handlers/fallback-exception-handler.ts b/src/core/errors/handlers/fallback-exception-handler.ts
new file mode 100644
index 00000000..c5199a7e
--- /dev/null
+++ b/src/core/errors/handlers/fallback-exception-handler.ts
@@ -0,0 +1,23 @@
+import { ExceptionCode } from "../exception-code";
+import type { ExceptionResult } from "../exception-result";
+
+export class FallbackExceptionHandler {
+  static handle(error: unknown): ExceptionResult {
+    return {
+      code: ExceptionCode.unknown,
+      message: resolveMessage(error),
+    };
+  }
+}
+
+function resolveMessage(error: unknown): string {
+  if (error instanceof Error && error.message.trim().length > 0) {
+    return error.message;
+  }
+
+  if (typeof error === "string" && error.trim().length > 0) {
+    return error;
+  }
+
+  return "Something went wrong. Please try again.";
+}
diff --git a/src/core/errors/handlers/network-exception-handler.ts b/src/core/errors/handlers/network-exception-handler.ts
new file mode 100644
index 00000000..822bc356
--- /dev/null
+++ b/src/core/errors/handlers/network-exception-handler.ts
@@ -0,0 +1,44 @@
+import { ExceptionCode } from "../exception-code";
+import type { ExceptionResult } from "../exception-result";
+
+export class NetworkExceptionHandler {
+  static canHandle(error: unknown): error is Error | DOMException {
+    if (!isErrorLike(error)) return false;
+    const message = error.message.toLowerCase();
+    return (
+      error.name === "AbortError" ||
+      error.name === "TimeoutError" ||
+      message.includes("failed to fetch") ||
+      message.includes("fetch failed") ||
+      message.includes("network") ||
+      message.includes("timeout")
+    );
+  }
+
+  static handle(error: Error | DOMException): ExceptionResult {
+    if (error.name === "AbortError") {
+      return {
+        code: ExceptionCode.cancelled,
+        message: "Request cancelled.",
+      };
+    }
+
+    const message = error.message.toLowerCase();
+    if (error.name === "TimeoutError" || message.includes("timeout")) {
+      return {
+        code: ExceptionCode.timeout,
+        message: "Request timeout, please try again.",
+      };
+    }
+
+    return {
+      code: ExceptionCode.network,
+      message: "Network connection failed.",
+    };
+  }
+}
+
+function isErrorLike(error: unknown): error is Error | DOMException {
+  if (error instanceof Error) return true;
+  return typeof DOMException !== "undefined" && error instanceof DOMException;
+}
diff --git a/src/core/errors/handlers/payment-exception-handler.ts b/src/core/errors/handlers/payment-exception-handler.ts
new file mode 100644
index 00000000..a8001b70
--- /dev/null
+++ b/src/core/errors/handlers/payment-exception-handler.ts
@@ -0,0 +1,30 @@
+import { ExceptionCode } from "../exception-code";
+import type { ExceptionResult } from "../exception-result";
+
+export class PaymentExceptionHandler {
+  static canHandle(error: unknown): error is Error {
+    if (!(error instanceof Error)) return false;
+    const message = error.message.toLowerCase();
+    return (
+      message.includes("payment") ||
+      message.includes("stripe") ||
+      message.includes("ezpay") ||
+      message.includes("order")
+    );
+  }
+
+  static handle(error: Error): ExceptionResult {
+    const message = error.message.toLowerCase();
+    if (message.includes("cancel")) {
+      return {
+        code: ExceptionCode.cancelled,
+        message: "Payment was cancelled.",
+      };
+    }
+
+    return {
+      code: ExceptionCode.payment,
+      message: "Payment could not be completed. Please try again.",
+    };
+  }
+}
diff --git a/src/core/errors/handlers/storage-exception-handler.ts b/src/core/errors/handlers/storage-exception-handler.ts
new file mode 100644
index 00000000..d2fc719a
--- /dev/null
+++ b/src/core/errors/handlers/storage-exception-handler.ts
@@ -0,0 +1,43 @@
+import { ExceptionCode } from "../exception-code";
+import type { ExceptionResult } from "../exception-result";
+
+export class StorageExceptionHandler {
+  static canHandle(error: unknown): error is Error | DOMException {
+    if (!isErrorLike(error)) return false;
+    const message = error.message.toLowerCase();
+    return (
+      error.name === "QuotaExceededError" ||
+      error.name === "SecurityError" ||
+      message.includes("localstorage") ||
+      message.includes("indexeddb") ||
+      message.includes("quota") ||
+      message.includes("storage")
+    );
+  }
+
+  static handle(error: Error | DOMException): ExceptionResult {
+    if (error.name === "QuotaExceededError") {
+      return {
+        code: ExceptionCode.storage,
+        message: "Storage quota exceeded.",
+      };
+    }
+
+    if (error.name === "SecurityError") {
+      return {
+        code: ExceptionCode.storage,
+        message: "Storage permission denied.",
+      };
+    }
+
+    return {
+      code: ExceptionCode.storage,
+      message: "Local data could not be saved. Please try again.",
+    };
+  }
+}
+
+function isErrorLike(error: unknown): error is Error | DOMException {
+  if (error instanceof Error) return true;
+  return typeof DOMException !== "undefined" && error instanceof DOMException;
+}
diff --git a/src/core/errors/handlers/validation-exception-handler.ts b/src/core/errors/handlers/validation-exception-handler.ts
new file mode 100644
index 00000000..213aed78
--- /dev/null
+++ b/src/core/errors/handlers/validation-exception-handler.ts
@@ -0,0 +1,18 @@
+import { z } from "zod";
+
+import { ExceptionCode } from "../exception-code";
+import type { ExceptionResult } from "../exception-result";
+
+export class ValidationExceptionHandler {
+  static canHandle(error: unknown): error is z.ZodError | SyntaxError {
+    return error instanceof z.ZodError || error instanceof SyntaxError;
+  }
+
+  static handle(error?: z.ZodError | SyntaxError): ExceptionResult {
+    void error;
+    return {
+      code: ExceptionCode.validation,
+      message: "Data format changed unexpectedly. Please try again.",
+    };
+  }
+}
diff --git a/src/core/errors/index.ts b/src/core/errors/index.ts
new file mode 100644
index 00000000..cc717438
--- /dev/null
+++ b/src/core/errors/index.ts
@@ -0,0 +1,4 @@
+export * from "./app-exception";
+export * from "./exception-code";
+export * from "./exception-handler";
+export * from "./exception-result";
diff --git a/src/data/services/api/response_helper.ts b/src/data/services/api/response_helper.ts
index ff58efe4..e2baded8 100644
--- a/src/data/services/api/response_helper.ts
+++ b/src/data/services/api/response_helper.ts
@@ -5,10 +5,8 @@
  * 集中到这里。HTTP 拦截器（`http_client.ts`）已经对非 2xx 响应抛 `ApiError`；
  * 本工具处理第二种失败：2xx 但 `success: false` 的 envelope。
  *
- * 行为升级：失败时抛 `ApiError`（`ApiError extends Error`），而不是裸 `Error`。
- * 这样调用方在 `Result.err` 内能 `instanceof ApiError` 检查 `.code` / `.status`。
- *
- * 
+ * 失败时仍抛 `ApiError`，让底层保留 HTTP/API 上下文；进入仓库层 `Result`
+ * 后会被 `ExceptionHandler` 统一收敛为应用可消费的 `{ code, message }`。
  */
 import { ApiError, ErrorCode } from "./api_result";
 
diff --git a/src/stores/auth/auth-machine.ts b/src/stores/auth/auth-machine.ts
index 147d9df1..8ba1eb7f 100644
--- a/src/stores/auth/auth-machine.ts
+++ b/src/stores/auth/auth-machine.ts
@@ -3,6 +3,7 @@
  */
 import { setup, assign } from "xstate";
 
+import { ExceptionHandler } from "@/core/errors";
 import type { AuthProvider } from "@/lib/auth/auth_platform";
 
 import { AuthState, initialState } from "./auth-state";
@@ -23,6 +24,9 @@ export type { AuthState } from "./auth-state";
 export { initialState } from "./auth-state";
 export type { AuthEvent } from "./auth-events";
 
+const toAuthErrorMessage = (error: unknown): string =>
+  ExceptionHandler.message(error);
+
 // ============================================================
 // Machine
 //
@@ -119,8 +123,7 @@ export const authMachine = setup({
         onError: {
           target: "idle",
           actions: assign({
-            errorMessage: ({ event }) =>
-              event.error instanceof Error ? event.error.message : String(event.error),
+            errorMessage: ({ event }) => toAuthErrorMessage(event.error),
             hasInitialized: true,
           }),
         },
@@ -145,8 +148,7 @@ export const authMachine = setup({
         onError: {
           target: "idle",
           actions: assign({
-            errorMessage: ({ event }) =>
-              event.error instanceof Error ? event.error.message : String(event.error),
+            errorMessage: ({ event }) => toAuthErrorMessage(event.error),
             hasInitialized: true,
           }),
         },
@@ -174,8 +176,7 @@ export const authMachine = setup({
         onError: {
           target: "idle",
           actions: assign({
-            errorMessage: ({ event }) =>
-              event.error instanceof Error ? event.error.message : String(event.error),
+            errorMessage: ({ event }) => toAuthErrorMessage(event.error),
             hasInitialized: true,
           }),
         },
@@ -208,8 +209,7 @@ export const authMachine = setup({
         onError: {
           target: "idle",
           actions: assign({
-            errorMessage: ({ event }) =>
-              event.error instanceof Error ? event.error.message : String(event.error),
+            errorMessage: ({ event }) => toAuthErrorMessage(event.error),
             hasInitialized: true,
           }),
         },
@@ -231,8 +231,7 @@ export const authMachine = setup({
         onError: {
           target: "idle",
           actions: assign({
-            errorMessage: ({ event }) =>
-              event.error instanceof Error ? event.error.message : String(event.error),
+            errorMessage: ({ event }) => toAuthErrorMessage(event.error),
           }),
         },
       },
@@ -254,8 +253,7 @@ export const authMachine = setup({
           actions: assign(({ event }) => ({
             ...initialState,
             hasInitialized: true,
-            errorMessage:
-              event.error instanceof Error ? event.error.message : String(event.error),
+            errorMessage: toAuthErrorMessage(event.error),
           })),
         },
       },
@@ -281,8 +279,7 @@ export const authMachine = setup({
         onError: {
           target: "idle",
           actions: assign({
-            errorMessage: ({ event }) =>
-              event.error instanceof Error ? event.error.message : String(event.error),
+            errorMessage: ({ event }) => toAuthErrorMessage(event.error),
             hasInitialized: true,
           }),
         },
@@ -309,8 +306,7 @@ export const authMachine = setup({
         onError: {
           target: "idle",
           actions: assign({
-            errorMessage: ({ event }) =>
-              event.error instanceof Error ? event.error.message : String(event.error),
+            errorMessage: ({ event }) => toAuthErrorMessage(event.error),
             hasInitialized: true,
           }),
         },
diff --git a/src/stores/chat/chat-send-flow.ts b/src/stores/chat/chat-send-flow.ts
index 4b6857c5..33d09434 100644
--- a/src/stores/chat/chat-send-flow.ts
+++ b/src/stores/chat/chat-send-flow.ts
@@ -1,5 +1,6 @@
 import { fromCallback, fromPromise } from "xstate";
 
+import { ExceptionHandler } from "@/core/errors";
 import { MessageQueue } from "@/core/net/message-queue";
 import type { ChatSendResponse } from "@/data/dto/chat";
 import { getChatRepository } from "@/data/repositories/chat_repository";
@@ -131,8 +132,7 @@ function createMessageQueueActor(
       const output = await sendMessageViaHttp(content);
       sendBack({ type: "ChatQueuedHttpDone", output });
     } catch (error) {
-      const errorMessage =
-        error instanceof Error ? error.message : "Message send failed";
+      const errorMessage = ExceptionHandler.message(error);
       log.error("[chat-machine] message queue send failed", {
         error,
       });
diff --git a/src/stores/payment/payment-machine.helpers.ts b/src/stores/payment/payment-machine.helpers.ts
index 0b8341ee..f69388c9 100644
--- a/src/stores/payment/payment-machine.helpers.ts
+++ b/src/stores/payment/payment-machine.helpers.ts
@@ -1,3 +1,4 @@
+import { ExceptionHandler } from "@/core/errors";
 import { PaymentPlan, type PaymentPlansResponse } from "@/data/dto/payment";
 
 import type { PaymentState } from "./payment-state";
@@ -7,7 +8,7 @@ export const PAYMENT_TIMEOUT_ERROR_MESSAGE =
   "Payment timed out. Please try again.";
 
 export function toPaymentErrorMessage(error: unknown): string {
-  return error instanceof Error ? error.message : String(error);
+  return ExceptionHandler.message(error);
 }
 
 export function hasOrderPollingTimedOut(
diff --git a/src/utils/__tests__/result.test.ts b/src/utils/__tests__/result.test.ts
new file mode 100644
index 00000000..03906c40
--- /dev/null
+++ b/src/utils/__tests__/result.test.ts
@@ -0,0 +1,28 @@
+import { describe, expect, it } from "vitest";
+
+import { AppException, ExceptionCode } from "@/core/errors";
+
+import { Result, toError } from "../result";
+
+describe("Result error normalization", () => {
+  it("normalizes unknown thrown values to AppException", async () => {
+    const result = await Result.wrap(async () => {
+      throw "boom";
+    });
+
+    expect(Result.isErr(result)).toBe(true);
+    if (Result.isOk(result)) throw new Error("Expected Result.err");
+
+    expect(result.error).toBeInstanceOf(AppException);
+    expect(result.error.message).toBe("boom");
+    expect((result.error as AppException).code).toBe(ExceptionCode.unknown);
+  });
+
+  it("returns AppException from toError", () => {
+    const error = toError(new TypeError("Failed to fetch"));
+
+    expect(error).toBeInstanceOf(AppException);
+    expect(error.message).toBe("Network connection failed.");
+    expect((error as AppException).code).toBe(ExceptionCode.network);
+  });
+});
diff --git a/src/utils/result.ts b/src/utils/result.ts
index 0420ae9f..95967c49 100644
--- a/src/utils/result.ts
+++ b/src/utils/result.ts
@@ -10,10 +10,13 @@
  *     如需在同模块中混用，可用 `import { Result as StorageResult } from
  *     "@/data/storage/result"` 别名。
  *
- * `error` 固定为 `Error`（非 `unknown`）：HTTP 拦截器与共享 unwrap 都抛 `ApiError`
- * （`ApiError extends Error`），仓库 `Result.wrap` 捕获后用 `toError` 规范化，
- * 调用方能可靠地 `instanceof ApiError` / `error.message` 访问错误信息。
+ * `error` 仍固定为 `Error`（非 `unknown`）：仓库 `Result.wrap` 捕获后用
+ * `ExceptionHandler` 统一归一化为 `AppException`，调用方可以稳定读取
+ * `error.message`；需要结构化错误时可继续通过 `ExceptionHandler.handle(error)`
+ * 得到简化后的 `{ code, message }`。
  */
+import { AppException, ExceptionHandler } from "@/core/errors";
+
 import { Logger } from "./logger";
 
 export type Result<T> =
@@ -30,7 +33,7 @@ export const Result = {
   },
 
   /**
-   * 构造失败结果。`error` 接受任意 thrown 值，内部用 `toError` 归一化为 `Error`。
+   * 构造失败结果。`error` 接受任意 thrown 值，内部用 `toError` 归一化为 `AppException`。
    */
   err<T = never>(error: unknown): Result<T> {
     return { success: false, error: toError(error) };
@@ -56,11 +59,11 @@ export const Result = {
    * `*Api` 调用从「throw 风格」桥接到「Result 风格」。
    *
    * 错误处理策略（重点）：
-   *   1. 捕获后用 `toError` 规范化（保留 .stack / .code / .status 等字段）
+   *   1. 捕获后用 `toError` 规范化为 `AppException`，原始 thrown 值放入 `cause`
    *   2. 用 Logger 记录（带 stack + component=Result 标签）—— 调试 dev 控制台可见，
    *      生产环境走 JSON pipeline 接入日志平台
    *   3. 不重新抛出 —— 调用方拿到的永远是 `Result<T>`（throw 风格调用方可在
-   *      最外层显式 `throw Result.unwrap(r)`）
+   *      最外层显式 `throw r.error`）
    */
   async wrap<T>(thunk: () => Promise<T>): Promise<Result<T>> {
     try {
@@ -77,17 +80,11 @@ export const Result = {
 } as const;
 
 /**
- * 把任意 thrown 值规范化为 `Error`：
- *   - 已是 `Error` 子类 → 原样返回（保留 `.code` / `.status` 等自定义字段）
- *   - string → `new Error(str)`
- *   - 其他 → `new Error(JSON.stringify(value))`，失败则 `new Error(String(value))`
+ * 把任意 thrown 值规范化为 `AppException`：
+ *   - 已是 `AppException` → 原样返回
+ *   - 其他错误 → 交给 `ExceptionHandler` 收敛为 `{ code, message }`
+ *   - 原始值会保存在 `cause`，方便日志和调试继续追溯
  */
-export function toError(value: unknown): Error {
-  if (value instanceof Error) return value;
-  if (typeof value === "string") return new Error(value);
-  try {
-    return new Error(JSON.stringify(value));
-  } catch {
-    return new Error(String(value));
-  }
+export function toError(value: unknown): AppException {
+  return ExceptionHandler.toError(value);
 }
diff --git a/src/utils/session-storage.ts b/src/utils/session-storage.ts
index 364ddc88..c81d92c8 100644
--- a/src/utils/session-storage.ts
+++ b/src/utils/session-storage.ts
@@ -36,7 +36,7 @@ export class SessionAsyncUtil {
       const json = typeof value === "string" ? JSON.parse(value) : value;
       return Result.ok(schema.parse(json));
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -50,7 +50,7 @@ export class SessionAsyncUtil {
       await SessionAsyncUtil._storage.setItem(key, JSON.stringify(validated));
       return Result.ok(undefined);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -59,15 +59,11 @@ export class SessionAsyncUtil {
       await SessionAsyncUtil._storage.removeItem(key);
       return Result.ok(undefined);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 }
 
-function toError(e: unknown): Error {
-  return e instanceof Error ? e : new Error(String(e));
-}
-
 function createDefaultSessionStorage(): Storage {
   if (typeof window === "undefined") {
     return createStorage({ driver: memoryDriver() });
diff --git a/src/utils/storage.ts b/src/utils/storage.ts
index 92498a2d..9de399f3 100644
--- a/src/utils/storage.ts
+++ b/src/utils/storage.ts
@@ -50,7 +50,7 @@ export class SpAsyncUtil {
       if (value.length === 0) return Result.ok(null);
       return Result.ok(value);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -62,7 +62,7 @@ export class SpAsyncUtil {
       await SpAsyncUtil._storage.setItem(key, value);
       return Result.ok(undefined);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -74,7 +74,7 @@ export class SpAsyncUtil {
       if (typeof value !== "number" || !Number.isFinite(value)) return Result.ok(null);
       return Result.ok(Math.trunc(value));
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -83,7 +83,7 @@ export class SpAsyncUtil {
       await SpAsyncUtil._storage.setItem(key, value);
       return Result.ok(undefined);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -95,7 +95,7 @@ export class SpAsyncUtil {
       if (typeof value !== "number" || !Number.isFinite(value)) return Result.ok(null);
       return Result.ok(value);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -104,7 +104,7 @@ export class SpAsyncUtil {
       await SpAsyncUtil._storage.setItem(key, value);
       return Result.ok(undefined);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -116,7 +116,7 @@ export class SpAsyncUtil {
       if (typeof value !== "boolean") return Result.ok(null);
       return Result.ok(value);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -125,7 +125,7 @@ export class SpAsyncUtil {
       await SpAsyncUtil._storage.setItem(key, value);
       return Result.ok(undefined);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -138,7 +138,7 @@ export class SpAsyncUtil {
       if (!value.every((v) => typeof v === "string")) return Result.ok(null);
       return Result.ok(value);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -150,7 +150,7 @@ export class SpAsyncUtil {
       await SpAsyncUtil._storage.setItem(key, value);
       return Result.ok(undefined);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -166,7 +166,7 @@ export class SpAsyncUtil {
       const parsed = schema.parse(json);
       return Result.ok(parsed);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -180,7 +180,7 @@ export class SpAsyncUtil {
       await SpAsyncUtil._storage.setItem(key, JSON.stringify(validated));
       return Result.ok(undefined);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -190,7 +190,7 @@ export class SpAsyncUtil {
       await SpAsyncUtil._storage.removeItem(key);
       return Result.ok(undefined);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -199,7 +199,7 @@ export class SpAsyncUtil {
       await SpAsyncUtil._storage.clear();
       return Result.ok(undefined);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 
@@ -208,18 +208,11 @@ export class SpAsyncUtil {
       const exists = await SpAsyncUtil._storage.hasItem(key);
       return Result.ok(exists);
     } catch (e) {
-      return Result.err(toError(e));
+      return Result.err(e);
     }
   }
 }
 
-// ============================================================
-// 内部辅助
-// ============================================================
-function toError(e: unknown): Error {
-  return e instanceof Error ? e : new Error(String(e));
-}
-
 function createDefaultStorage(): Storage {
   if (typeof window === "undefined") {
     return createStorage({ driver: memoryDriver() });