diff --git a/pigx-upms/pigx-upms-biz/src/main/java/com/pig4cloud/pigx/admin/controller/SysClientController.java b/pigx-upms/pigx-upms-biz/src/main/java/com/pig4cloud/pigx/admin/controller/SysClientController.java
index 686dc1104..f81a5d972 100644
--- a/pigx-upms/pigx-upms-biz/src/main/java/com/pig4cloud/pigx/admin/controller/SysClientController.java
+++ b/pigx-upms/pigx-upms-biz/src/main/java/com/pig4cloud/pigx/admin/controller/SysClientController.java
@@ -20,6 +20,7 @@
 package com.pig4cloud.pigx.admin.controller;
 
 import cn.hutool.core.collection.CollUtil;
+import cn.hutool.core.util.ObjUtil;
 import cn.hutool.core.util.StrUtil;
 import cn.hutool.json.JSONUtil;
 import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
@@ -36,6 +37,7 @@ import com.pig4cloud.pigx.common.excel.annotation.ResponseExcel;
 import com.pig4cloud.pigx.common.log.annotation.SysLog;
 import com.pig4cloud.pigx.common.security.annotation.HasPermission;
 import com.pig4cloud.pigx.common.security.annotation.Inner;
+import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.validation.Valid;
@@ -65,14 +67,20 @@ public class SysClientController {
 	private final SysOauthClientDetailsService clientDetailsService;
 
 	/**
-	 * 通过ID查询
-	 * @param clientId clientId
-	 * @return SysOauthClientDetails
+	 * 根据客户端 ID 查询管理端展示详情。
+	 *
+	 * @param clientId OAuth2 客户端 ID
+	 * @return 客户端详情查询结果；客户端不存在时响应数据为 {@code null}
 	 */
+	@Operation(summary = "根据客户端 ID 查询详情")
 	@GetMapping("/{clientId}")
-	public R getByClientId(@PathVariable String clientId) {
+	public R<SysOauthClientDetailsDTO> getByClientId(@PathVariable String clientId) {
 		SysOauthClientDetails details = clientDetailsService
-			.getOne(Wrappers.<SysOauthClientDetails>lambdaQuery().eq(SysOauthClientDetails::getClientId, clientId));
+			.getOne(Wrappers.<SysOauthClientDetails>lambdaQuery().eq(SysOauthClientDetails::getClientId, clientId), false);
+		if (ObjUtil.isNull(details)) {
+			return R.ok();
+		}
+
 		String information = details.getAdditionalInformation();
 		String captchaFlag = JSONUtil.parseObj(information).getStr(CommonConstants.CAPTCHA_FLAG);
 		String encFlag = JSONUtil.parseObj(information).getStr(CommonConstants.ENC_FLAG);
@@ -142,11 +150,15 @@ public class SysClientController {
 	}
 
 	/**
-	 * Feign 查询客户端信息的接口
-	 * @param clientId 客户端 ID
-	 * @return 基本信息
+	 * 根据客户端 ID 查询 OAuth2 客户端详情。
+	 * <p>
+	 * 仅供认证中心通过 Feign 发起内部调用；{@link Inner} 校验内部调用标识，不对外提供公开访问。
+	 * </p>
+	 * @param clientId OAuth2 客户端 ID
+	 * @return 客户端详情查询结果；客户端不存在时响应数据为 {@code null}
 	 */
 	@Inner
+	@Operation(summary = "查询 OAuth2 客户端详情（内部调用）", hidden = true)
 	@GetMapping("/getClientDetailsById/{clientId}")
 	public R getClientDetailsById(@PathVariable String clientId) {
 		return R.ok(clientDetailsService.getOne(
diff --git a/pigx-upms/pigx-upms-biz/src/test/java/com/pig4cloud/pigx/admin/controller/SysClientControllerTests.java b/pigx-upms/pigx-upms-biz/src/test/java/com/pig4cloud/pigx/admin/controller/SysClientControllerTests.java
new file mode 100644
index 000000000..69c979213
--- /dev/null
+++ b/pigx-upms/pigx-upms-biz/src/test/java/com/pig4cloud/pigx/admin/controller/SysClientControllerTests.java
@@ -0,0 +1,61 @@
+/*
+ *    Copyright (c) 2018-2026, lengleng All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * Neither the name of pig4cloud.com nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ * Author: lengleng (wangiegie@gmail.com)
+ */
+
+package com.pig4cloud.pigx.admin.controller;
+
+import com.pig4cloud.pigx.admin.api.dto.SysOauthClientDetailsDTO;
+import com.pig4cloud.pigx.admin.api.entity.SysOauthClientDetails;
+import com.pig4cloud.pigx.admin.service.SysOauthClientDetailsService;
+import com.pig4cloud.pigx.common.core.util.R;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+class SysClientControllerTests {
+
+	@Test
+	void getByClientIdReturnsNullDataWhenClientDoesNotExist() {
+		SysOauthClientDetailsService clientDetailsService = mock(SysOauthClientDetailsService.class);
+		SysClientController controller = new SysClientController(clientDetailsService);
+		when(clientDetailsService.getOne(any(), eq(false))).thenReturn(null);
+
+		R<SysOauthClientDetailsDTO> result = controller.getByClientId("missing-client");
+
+		assertThat(result.isOk()).isTrue();
+		assertThat(result.getData()).isNull();
+	}
+
+	@Test
+	void getByClientIdHandlesNullAdditionalInformation() {
+		SysOauthClientDetailsService clientDetailsService = mock(SysOauthClientDetailsService.class);
+		SysClientController controller = new SysClientController(clientDetailsService);
+		SysOauthClientDetails details = new SysOauthClientDetails();
+		details.setClientId("client-without-additional-information");
+		when(clientDetailsService.getOne(any(), eq(false))).thenReturn(details);
+
+		R<SysOauthClientDetailsDTO> result = controller.getByClientId(details.getClientId());
+
+		assertThat(result.isOk()).isTrue();
+		assertThat(result.getData()).isNotNull();
+		assertThat(result.getData().getClientId()).isEqualTo(details.getClientId());
+	}
+
+}