diff --git a/apps/admin/src/composables/useAdminPlayerTransfer.ts b/apps/admin/src/composables/useAdminPlayerTransfer.ts
index dfeb908..d4cd969 100644
--- a/apps/admin/src/composables/useAdminPlayerTransfer.ts
+++ b/apps/admin/src/composables/useAdminPlayerTransfer.ts
@@ -2,6 +2,7 @@ import { ref, computed } from 'vue';
 import { ElMessage } from 'element-plus';
 import api from '../api';
 import { useAdminLocale } from './useAdminLocale';
+import { resolveApiError } from '../i18n/form-validation';
 import {
   depositAmountCap,
   parsePlayerAvailable,
@@ -36,6 +37,20 @@ export function useAdminPlayerTransfer(onSuccess?: () => void | Promise<void>) {
 
   const transferAmountDisabled = computed(() => transferAmountRange.value.max === 0);
 
+  /** 有上限时超出额度（勿用 el-input-number :max，否则会静默截断到上限） */
+  const transferAmountExceedsCap = computed(() => {
+    const max = transferAmountRange.value.max;
+    if (max === undefined) return false;
+    return transferAmount.value > max;
+  });
+
+  const transferAmountCapError = computed(() => {
+    if (!transferAmountExceedsCap.value) return '';
+    return transferType.value === 'deposit'
+      ? t('err.insufficient_credit')
+      : t('transfer.context.withdraw_exceed');
+  });
+
   function transferTitle() {
     const name = transferTarget.value?.username ?? transferTarget.value?.id ?? '';
     return transferType.value === 'deposit'
@@ -63,8 +78,7 @@ export function useAdminPlayerTransfer(onSuccess?: () => void | Promise<void>) {
         transferAmount.value = cap > 0 ? Math.min(100, cap) : 0;
       }
     } catch (e: unknown) {
-      const err = e as { response?: { data?: { error?: string } } };
-      ElMessage.error(err.response?.data?.error ?? t('msg.load_failed'));
+      ElMessage.error(resolveApiError(e, t, 'msg.load_failed'));
       transferVisible.value = false;
     } finally {
       transferContextLoading.value = false;
@@ -105,10 +119,7 @@ export function useAdminPlayerTransfer(onSuccess?: () => void | Promise<void>) {
       transferVisible.value = false;
       await onSuccess?.();
     } catch (e: unknown) {
-      const err = e as { response?: { data?: { error?: string } } };
-      const fallback =
-        transferType.value === 'deposit' ? t('msg.topup_failed') : t('msg.transfer_failed');
-      ElMessage.error(err.response?.data?.error ?? fallback);
+      ElMessage.error(resolveApiError(e, t, transferType.value === 'deposit' ? 'msg.topup_failed' : 'msg.transfer_failed'));
     } finally {
       transferLoading.value = false;
     }
@@ -125,6 +136,8 @@ export function useAdminPlayerTransfer(onSuccess?: () => void | Promise<void>) {
     transferContextLoading,
     transferAmountRange,
     transferAmountDisabled,
+    transferAmountExceedsCap,
+    transferAmountCapError,
     transferTitle,
     openTransfer,
     submitTransfer,
diff --git a/apps/admin/src/i18n/form-validation.ts b/apps/admin/src/i18n/form-validation.ts
index 4a14010..780a89a 100644
--- a/apps/admin/src/i18n/form-validation.ts
+++ b/apps/admin/src/i18n/form-validation.ts
@@ -15,7 +15,18 @@ export function resolveFormError(e: unknown, t: (key: string) => string): string
   return t('msg.form_invalid');
 }
 
-/** 从 API 错误响应提取可读文案（Nest 全局过滤器返回 `error` 字段） */
+/** Nest 默认 4xx 响应里 error 常为 "Bad Request" 等泛化文案，真实原因在 message */
+const GENERIC_HTTP_ERRORS = new Set([
+  'Bad Request',
+  'Unauthorized',
+  'Forbidden',
+  'Not Found',
+  'Conflict',
+  'Unprocessable Entity',
+  'Internal Server Error',
+]);
+
+/** 从 API 错误响应提取可读文案（兼容 GlobalExceptionFilter 与 Nest 默认格式） */
 export function resolveApiError(
   err: unknown,
   t: (key: string) => string,
@@ -23,8 +34,13 @@ export function resolveApiError(
 ): string {
   const data = (err as { response?: { data?: { error?: string | string[]; message?: string | string[] } } })
     ?.response?.data;
-  const raw = data?.error ?? data?.message;
-  if (Array.isArray(raw)) return raw.join('；');
-  if (typeof raw === 'string' && raw.trim()) return raw;
+  const msgRaw = data?.message;
+  const errRaw = data?.error;
+  const message = Array.isArray(msgRaw) ? msgRaw.join('；') : msgRaw;
+  const error = Array.isArray(errRaw) ? errRaw.join('；') : errRaw;
+  if (typeof message === 'string' && message.trim()) {
+    if (!error || GENERIC_HTTP_ERRORS.has(error)) return message;
+  }
+  if (typeof error === 'string' && error.trim() && !GENERIC_HTTP_ERRORS.has(error)) return error;
   return t(fallbackKey);
 }
diff --git a/apps/admin/src/views/AgentManager.vue b/apps/admin/src/views/AgentManager.vue
index f003d0a..bae5764 100644
--- a/apps/admin/src/views/AgentManager.vue
+++ b/apps/admin/src/views/AgentManager.vue
@@ -3,7 +3,7 @@ import { ref, onMounted, computed } from 'vue';
 import { useRouter } from 'vue-router';
 import { ElMessage, ElMessageBox } from 'element-plus';
 import { useAdminLocale } from '../composables/useAdminLocale';
-import { resolveFormError } from '../i18n/form-validation';
+import { resolveFormError, resolveApiError } from '../i18n/form-validation';
 import api from '../api';
 import { clearStaffSession } from '../stores/auth';
 
@@ -43,6 +43,7 @@ import AgentCreditContext from '../components/AgentCreditContext.vue';
 import { useAdminPlayerTransfer } from '../composables/useAdminPlayerTransfer';
 import {
   fetchAdminAgentCreditContext,
+  maxCreditIncreaseAmount,
   type AgentCreditAdjustContext,
 } from '../utils/agent-credit-context';
 
@@ -571,8 +572,7 @@ async function openCredit(userId: string) {
   try {
     creditContext.value = await fetchAdminAgentCreditContext(userId);
   } catch (e: unknown) {
-    const err = e as { response?: { data?: { error?: string } } };
-    ElMessage.error(err.response?.data?.error ?? t('msg.load_failed'));
+    ElMessage.error(resolveApiError(e, t, 'msg.load_failed'));
     creditVisible.value = false;
   } finally {
     creditContextLoading.value = false;
@@ -584,6 +584,11 @@ async function submitCredit() {
     ElMessage.warning(t('msg.credit_zero'));
     return;
   }
+  const maxInc = maxCreditIncreaseAmount(creditContext.value);
+  if (creditForm.value.amount > 0 && maxInc !== undefined && creditForm.value.amount > maxInc) {
+    ElMessage.warning(t('err.insufficient_credit'));
+    return;
+  }
   creditLoading.value = true;
   try {
     await api.post(`/admin/agents/${editingId.value}/credit`, {
@@ -596,8 +601,7 @@ async function submitCredit() {
     load();
     refreshExpandedParents();
   } catch (e: unknown) {
-    const err = e as { response?: { data?: { error?: string } } };
-    ElMessage.error(err.response?.data?.error ?? t('msg.credit_adjust_failed'));
+    ElMessage.error(resolveApiError(e, t, 'msg.credit_adjust_failed'));
   } finally {
     creditLoading.value = false;
   }
@@ -737,6 +741,8 @@ const {
   transferContextLoading,
   transferAmountRange,
   transferAmountDisabled,
+  transferAmountExceedsCap,
+  transferAmountCapError,
   transferTitle,
   openTransfer,
   submitTransfer,
@@ -1340,11 +1346,10 @@ function creditTypeLabel(type: string) {
         <el-form-item :label="t('common.col_id')">
           <span>{{ transferTarget?.id }}</span>
         </el-form-item>
-        <el-form-item :label="t('user.field.amount')">
+        <el-form-item :label="t('user.field.amount')" :error="transferAmountCapError">
           <el-input-number
             v-model="transferAmount"
             :min="transferAmountRange.min"
-            :max="transferAmountRange.max"
             :disabled="transferAmountDisabled"
             :step="10"
             :precision="2"
@@ -1360,7 +1365,7 @@ function creditTypeLabel(type: string) {
         <el-button
           type="primary"
           :loading="transferLoading"
-          :disabled="transferAmountDisabled"
+          :disabled="transferAmountDisabled || transferAmountExceedsCap"
           @click="submitTransfer"
         >
           {{ t('common.confirm') }}
diff --git a/apps/admin/src/views/Agents.vue b/apps/admin/src/views/Agents.vue
index 31503f5..27d1367 100644
--- a/apps/admin/src/views/Agents.vue
+++ b/apps/admin/src/views/Agents.vue
@@ -1,7 +1,7 @@
 <script setup lang="ts">
 import { ref, onMounted } from 'vue';
 import { useAdminLocale } from '../composables/useAdminLocale';
-import { resolveFormError } from '../i18n/form-validation';
+import { resolveFormError, resolveApiError } from '../i18n/form-validation';
 import api from '../api';
 
 const { t } = useAdminLocale();
@@ -27,6 +27,7 @@ import AdminTableEmpty from '../components/AdminTableEmpty.vue';
 import AgentCreditContext from '../components/AgentCreditContext.vue';
 import {
   fetchAdminAgentCreditContext,
+  maxCreditIncreaseAmount,
   type AgentCreditAdjustContext,
 } from '../utils/agent-credit-context';
 
@@ -201,6 +202,11 @@ async function submitCredit() {
     ElMessage.warning(t('msg.credit_zero'));
     return;
   }
+  const maxInc = maxCreditIncreaseAmount(creditContext.value);
+  if (creditForm.value.amount > 0 && maxInc !== undefined && creditForm.value.amount > maxInc) {
+    ElMessage.warning(t('err.insufficient_credit'));
+    return;
+  }
   creditLoading.value = true;
   try {
     await api.post(`/admin/agents/${editingId.value}/credit`, {
@@ -212,8 +218,7 @@ async function submitCredit() {
     creditVisible.value = false;
     load();
   } catch (e: unknown) {
-    const err = e as { response?: { data?: { error?: string } } };
-    ElMessage.error(err.response?.data?.error ?? t('msg.credit_adjust_failed'));
+    ElMessage.error(resolveApiError(e, t, 'msg.credit_adjust_failed'));
   } finally {
     creditLoading.value = false;
   }
diff --git a/apps/admin/src/views/Users.vue b/apps/admin/src/views/Users.vue
index 7bdc649..07f9706 100644
--- a/apps/admin/src/views/Users.vue
+++ b/apps/admin/src/views/Users.vue
@@ -60,6 +60,8 @@ const {
   transferContextLoading,
   transferAmountRange,
   transferAmountDisabled,
+  transferAmountExceedsCap,
+  transferAmountCapError,
   transferTitle,
   openTransfer,
   submitTransfer,
@@ -757,11 +759,10 @@ function statusLabel(s: string) {
       <el-form-item :label="t('common.col_id')">
         <span>{{ transferTarget?.id }}</span>
       </el-form-item>
-      <el-form-item :label="t('user.field.amount')">
+      <el-form-item :label="t('user.field.amount')" :error="transferAmountCapError">
         <el-input-number
           v-model="transferAmount"
           :min="transferAmountRange.min"
-          :max="transferAmountRange.max"
           :disabled="transferAmountDisabled"
           :step="10"
           :precision="2"
@@ -777,7 +778,7 @@ function statusLabel(s: string) {
       <el-button
         type="primary"
         :loading="transferLoading"
-        :disabled="transferAmountDisabled"
+        :disabled="transferAmountDisabled || transferAmountExceedsCap"
         @click="submitTransfer"
       >
         {{ t('common.confirm') }}
diff --git a/apps/admin/src/views/agent/Players.vue b/apps/admin/src/views/agent/Players.vue
index 801159a..12eb9d9 100644
--- a/apps/admin/src/views/agent/Players.vue
+++ b/apps/admin/src/views/agent/Players.vue
@@ -143,6 +143,20 @@ const transferAmountDisabled = computed(() => {
   return max === 0;
 });
 
+/** 勿用 el-input-number :max，否则会静默截断到上限 */
+const transferAmountExceedsCap = computed(() => {
+  const max = transferAmountRange.value.max;
+  if (max === undefined) return false;
+  return transferAmount.value > max;
+});
+
+const transferAmountCapError = computed(() => {
+  if (!transferAmountExceedsCap.value) return '';
+  return transferType.value === 'deposit'
+    ? t('err.insufficient_credit')
+    : t('transfer.context.withdraw_exceed');
+});
+
 /* ─── Init ─── */
 onMounted(async () => {
   await loadProfile();
@@ -818,17 +832,20 @@ function statusTagType(s: string) {
         <el-form-item :label="t('common.col_id')">
           <span>{{ transferTarget?.id }}</span>
         </el-form-item>
-        <el-form-item :label="t('user.field.amount')">
+        <el-form-item :label="t('user.field.amount')" :error="transferAmountCapError">
           <el-input-number
             v-model="transferAmount"
-            :min="transferAmountRange.min" :max="transferAmountRange.max"
-            :disabled="transferAmountDisabled" :step="10" :precision="2" style="width: 100%"
+            :min="transferAmountRange.min"
+            :disabled="transferAmountDisabled"
+            :step="10"
+            :precision="2"
+            style="width: 100%"
           />
         </el-form-item>
       </el-form>
       <template #footer>
         <el-button @click="transferVisible = false">{{ t('common.cancel') }}</el-button>
-        <el-button type="primary" :loading="transferLoading" :disabled="transferAmountDisabled" @click="submitTransfer">{{ t('common.confirm') }}</el-button>
+        <el-button type="primary" :loading="transferLoading" :disabled="transferAmountDisabled || transferAmountExceedsCap" @click="submitTransfer">{{ t('common.confirm') }}</el-button>
       </template>
     </el-dialog>
 
diff --git a/apps/api/src/main.ts b/apps/api/src/main.ts
index 7b99e44..4ba52e1 100644
--- a/apps/api/src/main.ts
+++ b/apps/api/src/main.ts
@@ -4,10 +4,12 @@ import { SwaggerModule, DocumentBuilder } from '@nestjs/swagger';
 import { NestExpressApplication } from '@nestjs/platform-express';
 import { join } from 'path';
 import { AppModule } from './app.module';
+import { GlobalExceptionFilter } from './shared/common/filters';
 
 async function bootstrap() {
   const app = await NestFactory.create<NestExpressApplication>(AppModule);
   app.enableShutdownHooks();
+  app.useGlobalFilters(new GlobalExceptionFilter());
 
   const uploadDir = process.env.UPLOAD_DIR || join(__dirname, '..', '..', 'uploads');
   app.useStaticAssets(uploadDir, { prefix: '/uploads/' });
diff --git a/apps/api/src/shared/common/filters.ts b/apps/api/src/shared/common/filters.ts
index 6939094..b4923fa 100644
--- a/apps/api/src/shared/common/filters.ts
+++ b/apps/api/src/shared/common/filters.ts
@@ -20,7 +20,16 @@ export class GlobalExceptionFilter implements ExceptionFilter {
     if (exception instanceof HttpException) {
       status = exception.getStatus();
       const res = exception.getResponse();
-      message = typeof res === 'string' ? res : (res as { message?: string }).message || message;
+      if (typeof res === 'string') {
+        message = res;
+      } else if (typeof res === 'object' && res !== null) {
+        const body = res as { message?: string | string[] };
+        if (Array.isArray(body.message)) {
+          message = body.message.join('；');
+        } else if (typeof body.message === 'string' && body.message.trim()) {
+          message = body.message;
+        }
+      }
     } else if (exception instanceof Error) {
       message = exception.message;
     }