diff --git a/backend-single/src/main/java/com/emotion/exception/WechatApiException.java b/backend-single/src/main/java/com/emotion/exception/WechatApiException.java
new file mode 100644
index 0000000..0bc972d
--- /dev/null
+++ b/backend-single/src/main/java/com/emotion/exception/WechatApiException.java
@@ -0,0 +1,33 @@
+package com.emotion.exception;
+
+import lombok.Getter;
+
+/**
+ * 微信 API 业务异常
+ *
+ * <p>code 字段使用 HTTP 风格状态码：
+ * <ul>
+ *   <li>400: 微信 API 业务错误（errcode != 0）或 4xx 响应</li>
+ *   <li>500: 内部错误（JSON 解析失败）</li>
+ *   <li>502: 上游服务错误（5xx 响应 / network / non-JSON content-type）</li>
+ * </ul>
+ *
+ * <p>rawBody 字段仅用于服务端排查，绝不返回给前端。
+ */
+@Getter
+public class WechatApiException extends RuntimeException {
+
+    private static final long serialVersionUID = 1L;
+
+    /** HTTP 风格状态码 */
+    private final Integer code;
+
+    /** 原始响应体（仅服务端排查用，绝不返回给前端） */
+    private final String rawBody;
+
+    public WechatApiException(Integer code, String message, String rawBody) {
+        super(message);
+        this.code = code;
+        this.rawBody = rawBody;
+    }
+}