diff --git a/src/i18n/ja.ts b/src/i18n/ja.ts
index c3888f8..a557b83 100644
--- a/src/i18n/ja.ts
+++ b/src/i18n/ja.ts
@@ -192,6 +192,7 @@ export const jaOverrides = {
   'quota.unknownProvider': '不明',
   'common.confirm': '確認',
   'quota.service.xaiPaidAccount': '有料 API アカウント',
+  'quota.service.xaiPaidHealth': '有料 API の会話が利用可能です。xAI は現在、この OAuth 認証情報の総クォータを提供していません。',
   'quota.service.xaiPaidQuotaUnavailable': 'このアカウントの残りクォータは提供されていません。',
   'quota.confirm.button': 'リセットを実行',
   'quota.confirm.applicableLabel': '現在適用可能な回数',
diff --git a/src/i18n/locales/en.ts b/src/i18n/locales/en.ts
index 6665b83..b8a32a6 100644
--- a/src/i18n/locales/en.ts
+++ b/src/i18n/locales/en.ts
@@ -179,6 +179,7 @@ export const en: Record<MessageKey, string> = {
   'quota.unknownProvider': 'Unknown',
   'common.confirm': 'Confirm',
   'quota.service.xaiPaidAccount': 'Paid API account',
+  'quota.service.xaiPaidHealth': 'Paid API chat is available. xAI does not currently provide total quota data for this OAuth credential.',
   'quota.service.xaiPaidQuotaUnavailable': 'Remaining quota is not provided for this account.',
   'quota.confirm.button': 'Confirm Reset',
   'quota.confirm.applicableLabel': 'Currently applicable resets',
diff --git a/src/i18n/locales/zh-CN.ts b/src/i18n/locales/zh-CN.ts
index ca04983..53ed78d 100644
--- a/src/i18n/locales/zh-CN.ts
+++ b/src/i18n/locales/zh-CN.ts
@@ -178,6 +178,7 @@ export const zhCN = {
   'quota.unknownProvider': '未知',
   'common.confirm': '确认',
   'quota.service.xaiPaidAccount': '付费 API 账号',
+  'quota.service.xaiPaidHealth': '付费 API 对话可用。xAI 暂不为此 OAuth 凭证提供额度总量数据。',
   'quota.service.xaiPaidQuotaUnavailable': '此账号不提供剩余额度。',
   'quota.confirm.button': '确认重置',
   'quota.confirm.applicableLabel': '当前适用次数',
diff --git a/src/services/quotaService.ts b/src/services/quotaService.ts
index 4fbf68a..78479d3 100644
--- a/src/services/quotaService.ts
+++ b/src/services/quotaService.ts
@@ -1,3 +1,4 @@
+import { buildXaiBillingSummary, mergeXaiBillingSummaries, type XaiBillingConfig } from './xaiBilling';
 import {
   apiCallErrorMessage,
   isRecord,
@@ -466,102 +467,69 @@ export const quotaRowsFor = (provider: QuotaProvider, payload: unknown): QuotaRo
   }
 
   if (provider === 'xai') {
-    if (value.mode === 'paid-info') return [{
+    if (value.mode === 'paid-health' || value.mode === 'paid-info') return [{
       label: quotaText('quota.service.xaiPaidAccount'),
       remainingPercent: null,
-      detail: quotaText('quota.service.xaiPaidQuotaUnavailable'),
+      detail: quotaText(value.mode === 'paid-health'
+        ? 'quota.service.xaiPaidHealth' : 'quota.service.xaiPaidQuotaUnavailable'),
     }];
-    const payloads = isRecord(value.weekly) || isRecord(value.monthly)
-      ? [value.weekly, value.monthly]
-      : [value];
+    const build = (payload: unknown) => {
+      if (!isRecord(payload)) return null;
+      return buildXaiBillingSummary(
+        (isRecord(payload.config) ? payload.config : payload) as XaiBillingConfig,
+      );
+    };
+    const billing = isRecord(value.weekly) || isRecord(value.monthly)
+      ? mergeXaiBillingSummaries(build(value.weekly), build(value.monthly))
+      : build(value);
+    if (!billing) return [];
     const rows: QuotaRow[] = [];
-
-    payloads.forEach((payload) => {
-      if (!isRecord(payload)) return;
-      const config = isRecord(payload.config) ? payload.config : payload;
-      const currentPeriod = isRecord(config.current_period)
-        ? config.current_period
-        : isRecord(config.currentPeriod)
-          ? config.currentPeriod
-          : null;
-      const periodType = readString(currentPeriod, 'type').toLowerCase();
-      const weeklyUsed = numberValue(config.credit_usage_percent ?? config.creditUsagePercent);
-
-      const productItems = config.product_usage ?? config.productUsage;
-      if (weeklyUsed !== null || periodType.includes('week') || (Array.isArray(productItems) && productItems.length > 0)) {
-        rows.push({
-          label: quotaText('quota.service.weekly'),
-          remainingPercent: remainingFromUsedPercent(weeklyUsed),
-          reset: absoluteResetLabel(currentPeriod?.end),
-          resetAtMs: currentPeriod ? quotaResetFor(currentPeriod, ['end']) : undefined,
-        });
-        const productUsage = Array.isArray(config.product_usage)
-          ? config.product_usage
-          : Array.isArray(config.productUsage)
-            ? config.productUsage
-            : [];
-        productUsage.forEach((item, index) => {
-          if (!isRecord(item)) return;
-          rows.push({
-            label: readString(item, 'product')
-              || quotaText('quota.service.product.numbered', { index: index + 1 }),
-            remainingPercent: remainingFromUsedPercent(
-              item.usage_percent ?? item.usagePercent,
-            ),
-            reset: absoluteResetLabel(currentPeriod?.end),
-            resetAtMs: currentPeriod ? quotaResetFor(currentPeriod, ['end']) : undefined,
-          });
-        });
-      }
-
-      const limit = numberValue(config.monthly_limit ?? config.monthlyLimit);
-      const used = numberValue(config.used);
-      const includedUsed = used === null
-        ? null
-        : limit !== null && limit > 0
-          ? Math.min(used, limit)
-          : used;
-      if (limit !== null || used !== null) {
-        const remaining = limit !== null && limit > 0 && includedUsed !== null
-          ? ((limit - includedUsed) / limit) * 100
-          : null;
-        rows.push({
-          label: quotaText('quota.service.monthlyIncluded'),
-          remainingPercent: clampPercent(remaining),
-          reset: absoluteResetLabel(config.billing_period_end ?? config.billingPeriodEnd),
-          resetAtMs: quotaResetFor(config, ['billing_period_end', 'billingPeriodEnd']),
-          detail: limit !== null
-            ? `${formatUsdFromCents(Math.max(0, limit - (includedUsed ?? 0)))} / ${formatUsdFromCents(limit)}`
-            : undefined,
-        });
-      }
-
-      const onDemandCap = numberValue(config.on_demand_cap ?? config.onDemandCap);
-      const explicitOnDemandUsed = numberValue(config.on_demand_used ?? config.onDemandUsed);
-      const onDemandUsed = explicitOnDemandUsed
-        ?? (used !== null && limit !== null ? Math.max(0, used - limit) : null);
-      if (onDemandCap !== null && onDemandCap > 0) {
-        rows.push({
-          label: quotaText('quota.service.onDemand'),
-          remainingPercent: clampPercent(
-            onDemandUsed === null ? null : ((onDemandCap - onDemandUsed) / onDemandCap) * 100,
-          ),
-          reset: absoluteResetLabel(config.billing_period_end ?? config.billingPeriodEnd),
-          resetAtMs: quotaResetFor(config, ['billing_period_end', 'billingPeriodEnd']),
-          detail: `${formatUsdFromCents(Math.max(0, onDemandCap - (onDemandUsed ?? 0)))} / ${formatUsdFromCents(onDemandCap)}`,
-        });
-      }
-    });
-
-    const seen = new Set<string>();
-    return rows.filter((row) => {
-      const key = `${row.label}::${row.reset ?? ''}`;
-      if (seen.has(key)) return false;
-      seen.add(key);
-      return true;
-    });
+    const weeklyReset = {
+      reset: absoluteResetLabel(billing.periodEnd),
+      resetAtMs: billing.resetAtMs ?? undefined,
+    };
+    if (billing.periodType === 'weekly'
+      && (billing.usagePercent !== null || billing.periodEnd || billing.productUsage.length > 0)) {
+      rows.push({
+        label: quotaText('quota.service.weekly'),
+        remainingPercent: remainingFromUsedPercent(billing.usagePercent),
+        ...weeklyReset,
+      });
+    }
+    billing.productUsage.forEach((item) => rows.push({
+      label: item.product,
+      remainingPercent: remainingFromUsedPercent(item.usagePercent),
+    }));
+    const monthlyReset = {
+      reset: absoluteResetLabel(billing.billingPeriodEnd),
+      resetAtMs: quotaResetInstant(billing.billingPeriodEnd),
+    };
+    const amount = (cap: number | null, used: number | null) => {
+      const remaining = cap !== null && used !== null ? Math.max(0, cap - used) : null;
+      return cap === null ? formatUsdFromCents(remaining)
+        : `${formatUsdFromCents(remaining)} / ${formatUsdFromCents(cap)}`;
+    };
+    if (billing.onDemandCapCents !== null && billing.onDemandCapCents > 0) {
+      rows.push({
+        label: quotaText('quota.service.onDemand'),
+        remainingPercent: remainingFromUsedPercent(billing.onDemandUsedPercent),
+        detail: amount(billing.onDemandCapCents, billing.onDemandUsedCents),
+      });
+    }
+    if (billing.monthlyLimitCents !== null || billing.usedCents !== null || billing.billingPeriodEnd) {
+      rows.push({
+        label: quotaText('quota.service.monthlyIncluded'),
+        remainingPercent: remainingFromUsedPercent(billing.usedPercent),
+        detail: amount(billing.monthlyLimitCents, billing.includedUsedCents),
+        ...monthlyReset,
+      });
+    }
+    return rows.length > 0 ? rows : [{
+      label: quotaText(billing.periodType === 'weekly'
+        ? 'quota.service.weekly' : 'quota.service.monthlyIncluded'),
+      remainingPercent: null,
+    }];
   }
-
   const nested = parseBody(value.body);
   const summary = !Array.isArray(value.groups) && isRecord(nested) ? nested : value;
   const groups = Array.isArray(summary.groups) ? summary.groups : [];
@@ -656,10 +624,31 @@ const requestQuotaPayload = async (
   return parseBody(response.body ?? response.bodyText);
 };
 
+const callXaiPaidHealth = async (authIndex: string): Promise<unknown> => {
+  const header = { Authorization: 'Bearer $TOKEN$', accept: 'application/json' };
+  const [profile, chat] = await Promise.allSettled([
+    requestQuotaPayload(authIndex, 'https://api.x.ai/v1/me', header, 'GET', undefined, 15_000),
+    requestQuotaPayload(authIndex, 'https://api.x.ai/v1/chat/completions', {
+      ...header, 'Content-Type': 'application/json',
+    }, 'POST', JSON.stringify({
+      model: 'grok-4.5',
+      messages: [{ role: 'user', content: 'ping' }],
+      max_tokens: 1,
+      stream: false,
+    }), 15_000),
+  ]);
+  if (chat.status === 'rejected') throw chat.reason;
+  const record = profile.status === 'fulfilled' && isRecord(profile.value) ? profile.value : {};
+  return {
+    mode: 'paid-health', plan_type: 'Paid',
+    userId: readString(record, 'user_id', 'userId') || undefined,
+    teamId: readString(record, 'team_id', 'teamId') || undefined,
+  };
+};
 const callXaiQuota = async (file: AuthFile): Promise<unknown> => {
   const authIndex = normalizeAuthIndex(file.auth_index ?? file.authIndex);
   if (!authIndex) throw new Error(quotaText('quota.service.error.missingAuthIndex'));
-  if (isPaidXaiFile(file)) return { mode: 'paid-info', plan_type: 'Paid' };
+  if (isPaidXaiFile(file)) return callXaiPaidHealth(authIndex);
   const header = { ...headersByProvider.xai };
   const userId = await resolveXaiUserId(file);
   if (userId) header['x-userid'] = userId;
@@ -674,7 +663,11 @@ const callXaiQuota = async (file: AuthFile): Promise<unknown> => {
   if (quotaRowsFor('xai', payload).length > 0) return payload;
   const billingError = weekly.status === 'rejected' && monthly.status === 'rejected'
     ? weekly.reason : new Error(quotaText('quota.service.error.unrecognized'));
-  throw billingError;
+  try {
+    return await callXaiPaidHealth(authIndex);
+  } catch {
+    throw billingError;
+  }
 };
 
 const booleanValue = (value: unknown): boolean | null => {
diff --git a/src/services/xaiBilling.ts b/src/services/xaiBilling.ts
new file mode 100644
index 0000000..96170bb
--- /dev/null
+++ b/src/services/xaiBilling.ts
@@ -0,0 +1,304 @@
+export interface XaiBillingCent {
+  val?: number | string;
+}
+
+export interface XaiBillingPeriod {
+  type?: string;
+  start?: string;
+  end?: string;
+}
+
+export interface XaiBillingProductUsage {
+  product?: string;
+  usagePercent?: number | string | null;
+  usage_percent?: number | string | null;
+}
+
+export interface XaiBillingConfig {
+  currentPeriod?: XaiBillingPeriod | null;
+  current_period?: XaiBillingPeriod | null;
+  creditUsagePercent?: number | string | null;
+  credit_usage_percent?: number | string | null;
+  productUsage?: XaiBillingProductUsage[] | null;
+  product_usage?: XaiBillingProductUsage[] | null;
+  monthlyLimit?: XaiBillingCent | number | string | null;
+  monthly_limit?: XaiBillingCent | number | string | null;
+  used?: XaiBillingCent | number | string | null;
+  onDemandCap?: XaiBillingCent | number | string | null;
+  on_demand_cap?: XaiBillingCent | number | string | null;
+  onDemandUsed?: XaiBillingCent | number | string | null;
+  on_demand_used?: XaiBillingCent | number | string | null;
+  billingPeriodStart?: string;
+  billing_period_start?: string;
+  billingPeriodEnd?: string;
+  billing_period_end?: string;
+}
+
+export interface XaiBillingPayload {
+  config?: XaiBillingConfig | null;
+}
+
+export type XaiBillingPeriodType = 'weekly' | 'monthly' | 'unknown';
+
+export interface XaiProductUsageSummary {
+  product: string;
+  usagePercent: number | null;
+}
+
+export interface XaiBillingSummary {
+  mode: 'billing' | 'paid-health';
+  source?: 'cli-chat-proxy' | 'api.x.ai-fallback';
+  planType?: 'paid';
+  healthStatus?: 'chat-ok';
+  userId?: string;
+  teamId?: string;
+  periodType: XaiBillingPeriodType;
+  usagePercent: number | null;
+  periodStart?: string;
+  periodEnd?: string;
+  productUsage: XaiProductUsageSummary[];
+  monthlyLimitCents: number | null;
+  usedCents: number | null;
+  includedUsedCents: number | null;
+  onDemandCapCents: number | null;
+  onDemandUsedCents: number | null;
+  onDemandUsedPercent: number | null;
+  billingPeriodStart?: string;
+  billingPeriodEnd?: string;
+  usedPercent: number | null;
+  resetAtMs?: number | null;
+  periodHours?: number | null;
+}
+
+export function normalizeStringValue(value: unknown): string | null {
+  if (typeof value === 'string') {
+    const trimmed = value.trim();
+    return trimmed ? trimmed : null;
+  }
+  if (typeof value === 'number' && Number.isFinite(value)) {
+    return value.toString();
+  }
+  return null;
+}
+
+export function normalizeNumberValue(value: unknown): number | null {
+  if (typeof value === 'number' && Number.isFinite(value)) return value;
+  if (typeof value === 'string') {
+    const trimmed = value.trim();
+    if (!trimmed) return null;
+    const parsed = Number(trimmed);
+    return Number.isFinite(parsed) ? parsed : null;
+  }
+  return null;
+}
+
+export function parseIsoToMs(value: unknown): number | null {
+  if (typeof value !== 'string') return null;
+  const trimmed = value.trim();
+  if (!trimmed) return null;
+  const normalized = trimmed.replace(/(\.\d{6})\d+/, '$1');
+  const ms = new Date(normalized).getTime();
+  return Number.isFinite(ms) ? ms : null;
+}
+export function parseUnixToMs(value: unknown): number | null {
+  const numeric =
+    typeof value === 'number' ? value : typeof value === 'string' ? Number(value.trim()) : NaN;
+  if (!Number.isFinite(numeric) || numeric <= 0) return null;
+  return numeric < 1e11 ? numeric * 1000 : numeric;
+}
+export function resolveResetMs(candidates: readonly unknown[]): number | null {
+  for (const candidate of candidates) {
+    const iso = parseIsoToMs(candidate);
+    if (iso !== null) return iso;
+    const unix = parseUnixToMs(candidate);
+    if (unix !== null) return unix;
+  }
+  return null;
+}
+function normalizeXaiCentValue(value: XaiBillingConfig['monthlyLimit']): number | null {
+  if (value === undefined || value === null) return null;
+  if (typeof value === 'object' && !Array.isArray(value)) {
+    return normalizeNumberValue((value as { val?: unknown }).val);
+  }
+  return normalizeNumberValue(value);
+}
+
+function resolveXaiPeriodType(period?: XaiBillingPeriod | null): XaiBillingPeriodType {
+  const rawType = normalizeStringValue(period?.type)?.toLowerCase() ?? '';
+  if (rawType.includes('weekly')) return 'weekly';
+  if (rawType.includes('monthly')) return 'monthly';
+  return 'unknown';
+}
+
+function normalizeXaiProductUsage(
+  productUsage: XaiBillingConfig['productUsage'],
+  fallbackPrefix: string
+): XaiProductUsageSummary[] {
+  if (!Array.isArray(productUsage)) return [];
+
+  return productUsage
+    .map((item, index): XaiProductUsageSummary | null => {
+      if (!item || typeof item !== 'object') return null;
+      const product = normalizeStringValue(item.product) ?? `${fallbackPrefix} ${index + 1}`;
+      const usagePercent = normalizeNumberValue(item.usagePercent ?? item.usage_percent);
+      return { product, usagePercent };
+    })
+    .filter((item): item is XaiProductUsageSummary => item !== null);
+}
+
+const emptyXaiBillingSummary = (): XaiBillingSummary => ({
+  mode: 'billing',
+  source: 'cli-chat-proxy',
+  periodType: 'unknown',
+  usagePercent: null,
+  productUsage: [],
+  monthlyLimitCents: null,
+  usedCents: null,
+  includedUsedCents: null,
+  onDemandCapCents: null,
+  onDemandUsedCents: null,
+  onDemandUsedPercent: null,
+  usedPercent: null,
+});
+
+function xaiPeriodInstants(
+  periodStart: string | undefined,
+  periodEnd: string | undefined
+): { resetAtMs: number | null; periodHours: number | null } {
+  const resetAtMs = resolveResetMs([periodEnd]);
+  const startMs = resolveResetMs([periodStart]);
+  const periodHours =
+    resetAtMs !== null && startMs !== null && resetAtMs > startMs
+      ? (resetAtMs - startMs) / 3_600_000
+      : null;
+  return { resetAtMs, periodHours };
+}
+
+export function buildXaiBillingSummary(
+  config: XaiBillingConfig | null | undefined
+): XaiBillingSummary | null {
+  if (!config || typeof config !== 'object') return null;
+
+  const summary = emptyXaiBillingSummary();
+  const currentPeriod = config.currentPeriod ?? config.current_period ?? null;
+  const periodType = resolveXaiPeriodType(currentPeriod);
+  const creditUsagePercent = normalizeNumberValue(
+    config.creditUsagePercent ?? config.credit_usage_percent
+  );
+  const periodStart =
+    normalizeStringValue(currentPeriod?.start) ??
+    normalizeStringValue(config.billingPeriodStart ?? config.billing_period_start) ??
+    undefined;
+  const periodEnd =
+    normalizeStringValue(currentPeriod?.end) ??
+    normalizeStringValue(config.billingPeriodEnd ?? config.billing_period_end) ??
+    undefined;
+  const productUsage = normalizeXaiProductUsage(
+    config.productUsage ?? config.product_usage,
+    'Product'
+  );
+
+  const monthlyLimitCents = normalizeXaiCentValue(config.monthlyLimit ?? config.monthly_limit);
+  const usedCents = normalizeXaiCentValue(config.used);
+  const onDemandCapCents = normalizeXaiCentValue(config.onDemandCap ?? config.on_demand_cap);
+  const explicitOnDemandUsedCents = normalizeXaiCentValue(
+    config.onDemandUsed ?? config.on_demand_used
+  );
+  const billingPeriodStart =
+    normalizeStringValue(config.billingPeriodStart ?? config.billing_period_start) ?? undefined;
+  const billingPeriodEnd =
+    normalizeStringValue(config.billingPeriodEnd ?? config.billing_period_end) ?? undefined;
+
+  const includedUsedCents =
+    usedCents === null
+      ? null
+      : monthlyLimitCents !== null && monthlyLimitCents > 0
+        ? Math.min(usedCents, monthlyLimitCents)
+        : usedCents;
+  const derivedOnDemandUsedCents =
+    usedCents !== null && monthlyLimitCents !== null
+      ? Math.max(0, usedCents - monthlyLimitCents)
+      : null;
+  const onDemandUsedCents = explicitOnDemandUsedCents ?? derivedOnDemandUsedCents;
+  const usedPercent =
+    monthlyLimitCents !== null && monthlyLimitCents > 0 && includedUsedCents !== null
+      ? (includedUsedCents / monthlyLimitCents) * 100
+      : null;
+  const onDemandUsedPercent =
+    onDemandCapCents !== null && onDemandCapCents > 0 && onDemandUsedCents !== null
+      ? (onDemandUsedCents / onDemandCapCents) * 100
+      : null;
+
+  const hasWeeklyData =
+    creditUsagePercent !== null || periodType === 'weekly' || productUsage.length > 0;
+  const hasMonthlyData =
+    monthlyLimitCents !== null ||
+    usedCents !== null ||
+    (!hasWeeklyData && (onDemandCapCents !== null || !!billingPeriodEnd));
+
+  if (!hasWeeklyData && !hasMonthlyData) return null;
+
+  summary.periodType = hasWeeklyData
+    ? periodType === 'unknown'
+      ? 'weekly'
+      : periodType
+    : 'monthly';
+  summary.usagePercent = hasWeeklyData ? creditUsagePercent : usedPercent;
+  summary.periodStart = hasWeeklyData ? periodStart : billingPeriodStart;
+  summary.periodEnd = hasWeeklyData ? periodEnd : billingPeriodEnd;
+  summary.productUsage = productUsage;
+  summary.monthlyLimitCents = monthlyLimitCents;
+  summary.usedCents = usedCents;
+  summary.includedUsedCents = includedUsedCents;
+  summary.onDemandCapCents = onDemandCapCents;
+  summary.onDemandUsedCents = onDemandUsedCents;
+  summary.onDemandUsedPercent = onDemandUsedPercent;
+  summary.billingPeriodStart = hasMonthlyData ? billingPeriodStart : undefined;
+  summary.billingPeriodEnd = hasMonthlyData ? billingPeriodEnd : undefined;
+  summary.usedPercent = usedPercent;
+
+  const periodInstants = xaiPeriodInstants(summary.periodStart, summary.periodEnd);
+  summary.resetAtMs = periodInstants.resetAtMs;
+  summary.periodHours = periodInstants.periodHours;
+
+  return summary;
+}
+
+export function mergeXaiBillingSummaries(
+  primary: XaiBillingSummary | null,
+  fallback: XaiBillingSummary | null
+): XaiBillingSummary | null {
+  if (!primary) return fallback;
+  if (!fallback) return primary;
+
+  const periodSummary =
+    primary.periodType !== 'unknown'
+      ? primary
+      : fallback.periodType !== 'unknown'
+        ? fallback
+        : primary;
+  const periodStart = periodSummary.periodStart;
+  const periodEnd = periodSummary.periodEnd;
+  const periodInstants = xaiPeriodInstants(periodStart, periodEnd);
+
+  return {
+    mode: 'billing',
+    source: 'cli-chat-proxy',
+    periodType: periodSummary.periodType,
+    usagePercent: primary.usagePercent ?? fallback.usagePercent,
+    periodStart,
+    periodEnd,
+    resetAtMs: periodInstants.resetAtMs,
+    periodHours: periodInstants.periodHours,
+    productUsage: primary.productUsage.length > 0 ? primary.productUsage : fallback.productUsage,
+    monthlyLimitCents: primary.monthlyLimitCents ?? fallback.monthlyLimitCents,
+    usedCents: primary.usedCents ?? fallback.usedCents,
+    includedUsedCents: primary.includedUsedCents ?? fallback.includedUsedCents,
+    onDemandCapCents: primary.onDemandCapCents ?? fallback.onDemandCapCents,
+    onDemandUsedCents: primary.onDemandUsedCents ?? fallback.onDemandUsedCents,
+    onDemandUsedPercent: primary.onDemandUsedPercent ?? fallback.onDemandUsedPercent,
+    billingPeriodStart: primary.billingPeriodStart ?? fallback.billingPeriodStart,
+    billingPeriodEnd: primary.billingPeriodEnd ?? fallback.billingPeriodEnd,
+    usedPercent: primary.usedPercent ?? fallback.usedPercent,
+  };
+}
diff --git a/tests/quotaRendering.test.tsx b/tests/quotaRendering.test.tsx
index 649837e..4608348 100644
--- a/tests/quotaRendering.test.tsx
+++ b/tests/quotaRendering.test.tsx
@@ -2,6 +2,7 @@ import { describe, expect, it } from 'bun:test';
 import { renderToStaticMarkup } from 'react-dom/server';
 import { I18nProvider } from '../src/i18n';
 import { QuotaCard } from '../src/pages/QuotaPage';
+import { quotaRowsFor } from '../src/services/quotaService';
 import type { QuotaState } from '../src/services/quotaService';
 
 const render = (quota: QuotaState, provider = 'codex') => renderToStaticMarkup(
@@ -28,6 +29,19 @@ describe('quota card rendering', () => {
     expect(html).toContain('获取/刷新额度');
   });
 
+  it('xAI 探测成功显示可用说明，100% 额度保留刷新按钮', () => {
+    const healthy = render({
+      status: 'success', rows: quotaRowsFor('xai', { mode: 'paid-health' }),
+    }, 'xai');
+    expect(healthy).toContain('付费 API 对话可用');
+    expect(healthy).not.toContain('real-quota-track');
+    const full = render({
+      status: 'success', rows: quotaRowsFor('xai', { config: { creditUsagePercent: 0 } }),
+    }, 'xai');
+    expect(full).toContain('剩余 100%');
+    expect(full).toContain('width:100%');
+    expect(full).not.toContain('disabled=""');
+  });
   it('缓存中的原始重置时间提供动态提示，过期额度不伪造为已恢复', () => {
     const html = render({ status: 'success', rows: [{ label: '5h', remainingPercent: 0, resetAtMs: Date.parse('2020-01-01T00:00:00Z') }] });
     expect(html).toContain('重置时间已到，请刷新确认');
diff --git a/tests/quotaRequests.test.ts b/tests/quotaRequests.test.ts
index d90414e..87f124c 100644
--- a/tests/quotaRequests.test.ts
+++ b/tests/quotaRequests.test.ts
@@ -122,38 +122,90 @@ describe('quota API compatibility', () => {
   });
 });
 
-describe('xAI quota queries without paid probes', () => {
+describe('xAI quota queries aligned with Management Center', () => {
   const file = { name: 'xai.json', provider: 'x-ai', auth_index: 'x' };
 
-  it('单个账单接口失败仍展示另一接口的数据，不触发收费探测', async () => {
+  it('一个账单失败时保留另一个接口的真实额度，不探测', async () => {
     handler = (request) => request.url.includes('format=credits')
       ? { status_code: 403, body: 'weekly denied' }
-      : success({ config: { monthlyLimit: 1000, used: 200 } });
+      : success({ config: { monthlyLimit: 1000, used: 0 } });
     const result = await loadQuota({ ...file, metadata: { user: { id: 'u' } } });
-    expect(result.status).toBe('success');
-    expect(result.rows[0].remainingPercent).toBe(80);
+    expect(result).toMatchObject({ status: 'success', rows: [{ remainingPercent: 100 }] });
     expect(calls).toHaveLength(2);
     calls.forEach((request) => expect(request.header['x-userid']).toBe('u'));
   });
 
-  it('查询付费账号只说明额度不可用，不要求确认也不发送计费请求', async () => {
+  it('付费账号直接探测，profile 失败不影响聊天成功', async () => {
+    handler = (request) => request.url.endsWith('/me')
+      ? { status_code: 403, body: 'profile denied' } : success({});
     const result = await loadQuota({ ...file, using_api: true, prefix: 'paid' });
-    expect(result.status).toBe('success');
+    expect(result).toMatchObject({ status: 'success', plan: 'Paid' });
     expect(result.rows[0].remainingPercent).toBeNull();
-    expect(result.rows[0].detail).toBe('此账号不提供剩余额度。');
-    expect(post).not.toHaveBeenCalled();
+    expect(result.rows[0].detail).toContain('付费 API 对话可用');
+    expect(calls).toHaveLength(2);
+    expect(calls.map((request) => request.url)).toEqual([
+      'https://api.x.ai/v1/me', 'https://api.x.ai/v1/chat/completions',
+    ]);
+    expect(JSON.parse(calls[1].data!)).toEqual({
+      model: 'grok-4.5', messages: [{ role: 'user', content: 'ping' }],
+      max_tokens: 1, stream: false,
+    });
+    expect(calls[1].method).toBe('POST');
+    expect(calls[1].header).toEqual({
+      Authorization: 'Bearer $TOKEN$', accept: 'application/json', 'Content-Type': 'application/json',
+    });
+    post.mock.calls.forEach((call) => expect(call[2]).toEqual({ timeoutMs: 15000 }));
   });
 
-  it('两个账单均无数据时返回查询错误，不自动发起付费测试', async () => {
-    handler = (request) => request.url.includes('cli-chat-proxy') ? { status_code: 403, body: 'billing denied' }
-      : { status_code: 429, body: 'paid denied' };
+  it('账单为空后探测成功只显示账户可用，不伪造额度', async () => {
+    handler = () => success({});
     const result = await loadQuota(file);
-    expect(result).toMatchObject({ status: 'error', error: 'billing denied' });
+    expect(result).toMatchObject({ status: 'success', plan: 'Paid', rows: [{ remainingPercent: null }] });
+    expect(calls).toHaveLength(4);
+  });
+
+  it('账单和回退都失败时保留原始账单错误', async () => {
+    handler = (request) => request.url.includes('cli-chat-proxy')
+      ? { status_code: 403, body: 'billing denied' } : { status_code: 429, body: 'paid denied' };
+    expect(await loadQuota(file)).toMatchObject({ status: 'error', error: 'billing denied' });
+    expect(calls).toHaveLength(4);
+  });
+
+  it('已识别付费账号聊天失败时显示聊天错误', async () => {
+    handler = (request) => request.url.endsWith('/me')
+      ? success({}) : { status_code: 429, body: 'chat denied' };
+    expect(await loadQuota({ ...file, using_api: true, prefix: 'paid' }))
+      .toMatchObject({ status: 'error', error: 'chat denied' });
+    expect(calls).toHaveLength(2);
+  });
+
+  it('合并缺失百分比与零用量后仍查询成功，不触发探测', async () => {
+    handler = (request) => success({ config: request.url.includes('format=credits')
+      ? { currentPeriod: { type: 'weekly' } } : { creditUsagePercent: 0 } });
+    expect(await loadQuota(file)).toMatchObject({
+      status: 'success', rows: [{ remainingPercent: 100 }],
+    });
+    expect(calls).toHaveLength(2);
+  });
+
+  it('已识别的空周周期或零按量上限不触发付费探测', async () => {
+    for (const config of [{ currentPeriod: { type: 'weekly' } }, { onDemandCap: 0 }]) {
+      calls = [];
+      handler = () => success({ config });
+      expect(await loadQuota(file)).toMatchObject({
+        status: 'success', rows: [{ remainingPercent: null }],
+      });
+      expect(calls).toHaveLength(2);
+    }
+  });
+  it('仅有账单周期也不触发付费回退', async () => {
+    handler = () => success({ config: { billingPeriodEnd: '2030-01-01T00:00:00Z' } });
+    expect(await loadQuota(file)).toMatchObject({
+      status: 'success', rows: [{ remainingPercent: null }],
+    });
     expect(calls).toHaveLength(2);
-    expect(calls.every((request) => request.method === 'GET')).toBe(true);
   });
 });
-
 describe('quota request synchronization', () => {
   it('跨页面重复刷新共用同一个请求', async () => {
     let release!: () => void;
diff --git a/tests/quotaService.test.ts b/tests/quotaService.test.ts
index 19a65f4..c83e040 100644
--- a/tests/quotaService.test.ts
+++ b/tests/quotaService.test.ts
@@ -302,4 +302,24 @@ describe('quotaRowsFor', () => {
     expect(rows.find((row) => row.label === '月度包含额度')?.remainingPercent).toBe(0);
     expect(rows.find((row) => row.label === '按量付费额度')?.remainingPercent).toBe(60);
   });
+
+  it('xAI 保留 0 和 100 的边界值，缺失用量不显示全额余额', () => {
+    expect(quotaRowsFor('xai', { config: { creditUsagePercent: 0 } })[0].remainingPercent).toBe(100);
+    expect(quotaRowsFor('xai', { config: { creditUsagePercent: 100 } })[0].remainingPercent).toBe(0);
+    expect(quotaRowsFor('xai', { config: { monthlyLimit: { val: 15000 }, used: { val: 0 } } })[0].remainingPercent).toBe(100);
+    const unknown = quotaRowsFor('xai', { config: { monthlyLimit: 15000 } })[0];
+    expect(unknown.remainingPercent).toBeNull();
+    expect(unknown.detail).not.toBe('US$150.00 / US$150.00');
+    expect(quotaRowsFor('xai', { config: { monthlyLimit: 15000, used: 15000 } })[0].remainingPercent).toBe(0);
+  });
+
+  it('xAI 按字段合并并保留活动周期，不由月账单补齐周重置时间', () => {
+    const rows = quotaRowsFor('xai', {
+      weekly: { config: { currentPeriod: { type: 'weekly' } } },
+      monthly: { config: { creditUsagePercent: 0, currentPeriod: { type: 'monthly', end: '2030-01-01T00:00:00Z' } } },
+    });
+    expect(rows).toHaveLength(1);
+    expect(rows[0].remainingPercent).toBe(100);
+    expect(rows[0].resetAtMs).toBeUndefined();
+  });
 });