diff --git a/docs-site/src/content/docs/guides/providers.md b/docs-site/src/content/docs/guides/providers.md
index 4615c0726..cdd5d36b9 100644
--- a/docs-site/src/content/docs/guides/providers.md
+++ b/docs-site/src/content/docs/guides/providers.md
@@ -221,6 +221,31 @@ validates the key, and stores it. Notable entries:
 Most use the `openai-chat` adapter with a bearer key; a few that expose only an Anthropic-compatible
 endpoint (e.g. **Xiaomi MiMo**) use the `anthropic` adapter (`x-api-key`).
 
+### A6API credit quota
+
+A custom `openai-chat` provider using `authMode: "key"` and the canonical
+`https://api.a6api.com` or `https://api.a6api.com/v1` base URL receives an A6API credit meter in
+the dashboard and from `ocx account refresh <provider>`. The provider name is arbitrary; detection
+uses the canonical HTTPS endpoint. The meter converts A6API token units into USD using the account's
+hard credit limit and displays the percentage consumed plus remaining credit. Token expiration is
+not shown as a quota reset because expiration does not imply that credit replenishes.
+
+```json
+{
+  "providers": {
+    "my-a6": {
+      "adapter": "openai-chat",
+      "authMode": "key",
+      "baseUrl": "https://api.a6api.com/v1",
+      "apiKey": "${A6API_API_KEY}"
+    }
+  }
+}
+```
+
+Quota probes send only the active key to the canonical A6API host and reject redirects. Malformed,
+negative, or internally inconsistent billing totals produce no report rather than a misleading bar.
+
 > **Tencent Cloud Coding Plan usage restriction:** Tencent documents this subscription for
 > interactive coding tools only. General API automation, custom application backends, and
 > non-interactive batch use are prohibited and may cause the plan key to be suspended.
diff --git a/docs-site/src/content/docs/ja/guides/providers.md b/docs-site/src/content/docs/ja/guides/providers.md
index ef2dd1d54..39c409315 100644
--- a/docs-site/src/content/docs/ja/guides/providers.md
+++ b/docs-site/src/content/docs/ja/guides/providers.md
@@ -152,6 +152,15 @@ opencodex v2.7.1 には組み込みプリセットが 50 個含まれていま
 大半は bearer キーと共に `openai-chat` アダプターを使い、Anthropic 互換エンドポイントのみを公開する一部
 (例: **Xiaomi MiMo**)は `anthropic` アダプター(`x-api-key`)を使います。
 
+### A6API クレジットクォータ
+
+`openai-chat`、`authMode: "key"`、正規の `https://api.a6api.com` または
+`https://api.a6api.com/v1` を使うカスタムプロバイダーでは、ダッシュボードと
+`ocx account refresh <provider>` に A6API クレジット使用量が表示されます。プロバイダー名は任意です。
+アカウントの hard credit limit を基準にトークン単位を USD に換算し、使用率と残高を表示します。トークン期限は補充を意味しないため、クォータの
+リセットとしては表示しません。アクティブキーだけを正規ホストへ送信し、リダイレクトを拒否します。負数や
+整合しない請求合計からはレポートを生成しません。
+
 > **Tencent Cloud Coding Plan の利用制限:** Tencent はこのサブスクリプションを対話型
 > コーディングツール専用としています。一般的な API 自動化、カスタムアプリのバックエンド、
 > 非対話型バッチ利用は禁止されており、プランキーが停止される場合があります。
diff --git a/docs-site/src/content/docs/ko/guides/providers.md b/docs-site/src/content/docs/ko/guides/providers.md
index 208839d81..7eb3651f0 100644
--- a/docs-site/src/content/docs/ko/guides/providers.md
+++ b/docs-site/src/content/docs/ko/guides/providers.md
@@ -152,6 +152,15 @@ opencodex v2.7.1에는 빌트인 프리셋이 50개 들어 있습니다. 키 방
 대부분은 bearer 키와 함께 `openai-chat` 어댑터를 사용하며, Anthropic 호환 엔드포인트만 노출하는 일부
 (예: **Xiaomi MiMo**)는 `anthropic` 어댑터(`x-api-key`)를 사용합니다.
 
+### A6API 크레딧 쿼터
+
+`openai-chat`, `authMode: "key"`, 공식 `https://api.a6api.com` 또는
+`https://api.a6api.com/v1` 주소를 사용하는 사용자 지정 프로바이더는 대시보드와
+`ocx account refresh <provider>`에서 A6API 크레딧 사용량을 표시합니다. 프로바이더 이름은 자유롭게 정할 수
+있습니다. 계정의 hard credit limit을 기준으로 토큰 단위를 USD로 환산해 사용률과 남은 크레딧을 표시하며, 토큰 만료는 충전을 뜻하지 않으므로 쿼터
+리셋으로 표시하지 않습니다. 활성 키만 공식 호스트로 전송하고 리디렉션을 거부하며, 음수이거나 서로 일치하지
+않는 결제 합계에는 보고서를 만들지 않습니다.
+
 > **Tencent Cloud Coding Plan 사용 제한:** Tencent는 이 구독을 대화형 코딩 도구 전용으로
 > 안내합니다. 일반 API 자동화, 사용자 애플리케이션 백엔드 및 비대화형 일괄 호출은 금지되며
 > 플랜 키가 정지될 수 있습니다.
diff --git a/docs-site/src/content/docs/ru/guides/providers.md b/docs-site/src/content/docs/ru/guides/providers.md
index d6df82506..7abe11970 100644
--- a/docs-site/src/content/docs/ru/guides/providers.md
+++ b/docs-site/src/content/docs/ru/guides/providers.md
@@ -163,6 +163,16 @@ opencodex поставляется с 53 встроенными пресетам
 только Anthropic-совместимую конечную точку (например, **Xiaomi MiMo**), используют адаптер
 `anthropic` (`x-api-key`).
 
+### Квота кредитов A6API
+
+Пользовательский провайдер с `openai-chat`, `authMode: "key"` и каноническим адресом
+`https://api.a6api.com` или `https://api.a6api.com/v1` показывает расход кредитов A6API в
+дашборде и в `ocx account refresh <provider>`. Имя провайдера может быть любым. Единицы токенов
+пересчитываются в USD по hard credit limit учётной записи; отображаются процент расхода и остаток. Срок действия токена не считается
+сбросом квоты, поскольку он не означает пополнение. Только активный ключ отправляется на
+канонический хост, перенаправления отклоняются, а отрицательные или несогласованные итоги биллинга
+не создают отчёт.
+
 > **Ограничение Tencent Cloud Coding Plan:** Tencent разрешает использовать эту подписку только
 > в интерактивных инструментах программирования. Автоматизация общего API, серверы пользовательских
 > приложений и неинтерактивные пакетные вызовы запрещены и могут привести к блокировке ключа плана.
diff --git a/docs-site/src/content/docs/zh-cn/guides/providers.md b/docs-site/src/content/docs/zh-cn/guides/providers.md
index 357ddbcac..d3579aee4 100644
--- a/docs-site/src/content/docs/zh-cn/guides/providers.md
+++ b/docs-site/src/content/docs/zh-cn/guides/providers.md
@@ -143,6 +143,14 @@ ChatGPT 转发预设。仪表盘的 **Add provider** 选择器会打开密钥提
 
 大多数使用带 bearer 密钥的 `openai-chat` adapter；少数仅暴露 Anthropic 兼容端点的提供商（例如 **Xiaomi MiMo**）使用 `anthropic` adapter（`x-api-key`）。
 
+### A6API 信用额度
+
+使用 `openai-chat`、`authMode: "key"` 以及规范地址 `https://api.a6api.com` 或
+`https://api.a6api.com/v1` 的自定义提供商，会在仪表板和 `ocx account refresh <provider>`
+中显示 A6API 信用使用情况；提供商名称可以自定义。系统依据账户的 hard credit limit 将令牌单位换算为 USD，并显示已用百分比和剩余额度。
+令牌到期不代表额度补充，因此不会显示为配额重置。只有当前活动密钥会发送到规范主机，重定向会被拒绝；负数
+或内部不一致的计费总数不会生成报告。
+
 > **腾讯云 Coding Plan 使用限制：**腾讯将此订阅限定为交互式编程工具使用。禁止通用 API
 > 自动化、自定义应用后端和非交互式批量调用；违规使用可能导致套餐密钥被停用。
 
diff --git a/src/providers/quota.ts b/src/providers/quota.ts
index 9a5831df7..2b3859d32 100644
--- a/src/providers/quota.ts
+++ b/src/providers/quota.ts
@@ -4,6 +4,7 @@ import { resolveEnvValue } from "../config";
 import { getValidAccessToken, getValidAccessTokenForAccount } from "../oauth";
 import { getAccountCredential, getAccountSet, getCredential } from "../oauth/store";
 import { antigravityUserAgent } from "../adapters/client-fingerprint";
+import { apiKeyPoolEntryId } from "./api-keys";
 import { getProviderRegistryEntry, providerCodexAccountMode } from "./registry";
 import type { OcxConfig, OcxProviderConfig } from "../types";
 import { isCanonicalOpenAiForwardProvider, OPENAI_CODEX_PROVIDER_ID } from "./openai-tiers";
@@ -15,8 +16,11 @@ const CACHE_TTL_MS = 5 * 60_000;
 const REQUEST_TIMEOUT_MS = 8_000;
 const KIMI_CODE_BASE_URL = "https://api.kimi.com/coding/v1";
 const KIMI_CODE_USAGE_URL = `${KIMI_CODE_BASE_URL}/usages`;
+const A6API_BASE_URL = "https://api.a6api.com";
 /** Keep a failed probe's previous row at most this long before dropping it. */
 const LAST_GOOD_MAX_AGE_MS = 30 * 60_000;
+const TERMINAL_QUOTA_FAILURE = Symbol("terminal-quota-failure");
+type ProviderQuotaProbeResult = ProviderQuotaReport | null | typeof TERMINAL_QUOTA_FAILURE;
 
 export interface ProviderQuotaWindow {
   label: string;
@@ -62,7 +66,13 @@ export function clearProviderQuotaCache(): void {
 
 function cacheKey(config: OcxConfig): string {
   const providers = Object.entries(config.providers)
-    .map(([name, provider]) => `${name}:${provider.adapter}:${provider.authMode ?? "key"}:${providerCodexAccountMode(name, provider) ?? "none"}:${provider.disabled === true ? "off" : "on"}:${provider.baseUrl}`)
+    .map(([name, provider]) => {
+      const resolvedKey = typeof provider.apiKey === "string"
+        ? resolveEnvValue(provider.apiKey)?.trim()
+        : undefined;
+      const activeKeyId = resolvedKey ? apiKeyPoolEntryId(resolvedKey) : "none";
+      return `${name}:${provider.adapter}:${provider.authMode ?? "key"}:${providerCodexAccountMode(name, provider) ?? "none"}:${provider.disabled === true ? "off" : "on"}:${provider.baseUrl}:${activeKeyId}`;
+    })
     .sort()
     .join("|");
   return `${config.defaultProvider}|${config.activeCodexAccountId ?? ""}|${providers}`;
@@ -118,6 +128,74 @@ function isBuiltInChatGptForwardProvider(name: string, provider: OcxProviderConf
   return name === OPENAI_CODEX_PROVIDER_ID && isCanonicalOpenAiForwardProvider(provider);
 }
 
+function isCanonicalA6apiBaseUrl(baseUrl: string): boolean {
+  const normalized = normalizedBaseUrl(baseUrl);
+  return normalized === A6API_BASE_URL || normalized === `${A6API_BASE_URL}/v1`;
+}
+
+function a6apiPayload(value: unknown): Record<string, unknown> | null {
+  const body = asRecord(value);
+  return asRecord(body?.data) ?? body;
+}
+
+function firstFinite(record: Record<string, unknown> | null, names: string[]): number | undefined {
+  if (!record) return undefined;
+  for (const name of names) {
+    const value = toFiniteNumber(record[name]);
+    if (value !== undefined) return value;
+  }
+  return undefined;
+}
+
+async function fetchA6apiQuota(provider: string, config: OcxProviderConfig): Promise<ProviderQuotaProbeResult> {
+  // Never send a configured API key to a lookalike host or through a redirect.
+  if (!isCanonicalA6apiBaseUrl(config.baseUrl)) return null;
+  const apiKey = resolveEnvValue(config.apiKey)?.trim();
+  if (!apiKey) return null;
+  const headers = { Accept: "application/json", Authorization: `Bearer ${apiKey}` } as const;
+  const [subscriptionResponse, tokenResponse] = await Promise.all([
+    fetch(`${A6API_BASE_URL}/dashboard/billing/subscription`, {
+      headers, redirect: "error", signal: AbortSignal.timeout(REQUEST_TIMEOUT_MS),
+    }),
+    fetch(`${A6API_BASE_URL}/api/usage/token/`, {
+      headers, redirect: "error", signal: AbortSignal.timeout(REQUEST_TIMEOUT_MS),
+    }),
+  ]);
+  if (!subscriptionResponse.ok || !tokenResponse.ok) {
+    const statuses = [subscriptionResponse.status, tokenResponse.status];
+    return statuses.some(status => status >= 400 && status < 500)
+      ? TERMINAL_QUOTA_FAILURE
+      : null;
+  }
+  const subscription = a6apiPayload(await subscriptionResponse.json().catch(() => null));
+  const token = a6apiPayload(await tokenResponse.json().catch(() => null));
+  const limitUsd = firstFinite(subscription, ["hard_limit_usd"]);
+  const grantedUnits = firstFinite(token, ["total_granted"]);
+  const usedUnits = firstFinite(token, ["total_used"]);
+  const availableUnits = firstFinite(token, ["total_available"]);
+  const reconciledUnits = usedUnits !== undefined && availableUnits !== undefined
+    ? usedUnits + availableUnits
+    : undefined;
+  const reconciliationTolerance = grantedUnits !== undefined
+    ? Math.abs(grantedUnits) * 1e-9
+    : 0;
+  if (limitUsd === undefined || grantedUnits === undefined || usedUnits === undefined
+    || availableUnits === undefined || limitUsd <= 0 || grantedUnits <= 0
+    || usedUnits < 0 || availableUnits < 0
+    || reconciledUnits === undefined
+    || Math.abs(reconciledUnits - grantedUnits) > reconciliationTolerance) return TERMINAL_QUOTA_FAILURE;
+  const usdPerUnit = limitUsd / grantedUnits;
+  const usedUsd = usedUnits * usdPerUnit;
+  const remainingUsd = Math.max(0, availableUnits * usdPerUnit);
+  const percent = normalizePercent((usedUsd / limitUsd) * 100);
+  if (percent === undefined) return TERMINAL_QUOTA_FAILURE;
+  const label = `API credits ($${remainingUsd.toFixed(2)} of $${limitUsd.toFixed(2)} remaining)`;
+  return report(provider, "a6api:billing", {
+    customWindows: [{ label, percent }],
+    updatedAt: Date.now(),
+  });
+}
+
 function report(provider: string, source: string, quota: ProviderQuota): ProviderQuotaReport | null {
   if (!hasQuotaRows(quota)) return null;
   return {
@@ -432,7 +510,7 @@ export async function fetchProviderAccountQuotas(
 function normalizedBaseUrl(value: string): string | null {
   try {
     const url = new URL(value);
-    if (url.search || url.hash) return null;
+    if (url.username || url.password || url.search || url.hash) return null;
     return `${url.origin.toLowerCase()}${url.pathname.replace(/\/+$/, "")}`;
   } catch {
     return null;
@@ -839,7 +917,7 @@ async function maybeFetchProviderQuota(
   provider: OcxProviderConfig,
   config: OcxConfig,
   forceRefresh: boolean,
-): Promise<ProviderQuotaReport | null> {
+): Promise<ProviderQuotaProbeResult> {
   if (provider.disabled === true) return null;
   try {
     if (isBuiltInChatGptForwardProvider(name, provider)) return fetchChatGptForwardQuota(config, name, provider, forceRefresh);
@@ -853,6 +931,9 @@ async function maybeFetchProviderQuota(
     if (provider.authMode === "key" && isCanonicalKimiCodeBaseUrl(provider.baseUrl)) {
       return fetchKimiQuota(name, provider);
     }
+    if ((provider.authMode ?? "key") === "key" && isCanonicalA6apiBaseUrl(provider.baseUrl)) {
+      return fetchA6apiQuota(name, provider);
+    }
     return null;
   } catch {
     return null;
@@ -875,19 +956,23 @@ export async function fetchProviderQuotaReports(config: OcxConfig, forceRefresh
 
   const promise = (async (): Promise<ProviderQuotaResponse> => {
     const previous = cache && cache.key === key ? cache.response.reports : [];
-    const fresh = (await Promise.all(
+    const probeResults = await Promise.all(
       Object.entries(config.providers).map(([name, provider]) => maybeFetchProviderQuota(name, provider, config, forceRefresh)),
-    )).filter((item): item is ProviderQuotaReport => item !== null);
-
-    // Keep bounded last-good rows when a probe fails (e.g. transient upstream flake); never
-    // re-stamp their timestamps, and drop rows older than LAST_GOOD_MAX_AGE_MS.
+    );
+    const fresh = probeResults.filter((item): item is ProviderQuotaReport => item !== null && item !== TERMINAL_QUOTA_FAILURE);
+    const terminalFailures = new Set(
+      Object.keys(config.providers).filter((_, index) => probeResults[index] === TERMINAL_QUOTA_FAILURE),
+    );
+
+    // Keep bounded last-good rows when a probe fails transiently; terminal-invalid provider
+    // responses explicitly suppress their old row. Never re-stamp preserved timestamps.
     // Note: the cache key encodes the provider set (name/adapter/authMode/disabled/baseUrl),
     // so previous rows always correspond to currently configured, enabled providers — a
     // disabled or removed provider changes the key and starts from an empty previous set.
     const cutoff = Date.now() - LAST_GOOD_MAX_AGE_MS;
     const byProvider = new Map<string, ProviderQuotaReport>();
     for (const item of previous) {
-      if (item.updatedAt >= cutoff) byProvider.set(item.provider, item);
+      if (item.updatedAt >= cutoff && !terminalFailures.has(item.provider)) byProvider.set(item.provider, item);
     }
     for (const item of fresh) byProvider.set(item.provider, item);
 
diff --git a/tests/provider-quota.test.ts b/tests/provider-quota.test.ts
index 11e22aaa4..258483dff 100644
--- a/tests/provider-quota.test.ts
+++ b/tests/provider-quota.test.ts
@@ -237,6 +237,222 @@ describe("fetchProviderQuotaReports", () => {
     } as OcxConfig;
   }
 
+  function a6apiOnlyConfig(baseUrl = "https://api.a6api.com/v1"): OcxConfig {
+    return {
+      defaultProvider: "a6api",
+      providers: {
+        a6api: { adapter: "openai-chat", authMode: "key", baseUrl, apiKey: "a6api-secret" },
+      },
+    } as OcxConfig;
+  }
+
+  test("A6API quota converts provider units to USD and exposes a displayable credit window", async () => {
+    const seen: Array<{ url: string; authorization?: string; redirect?: RequestRedirect }> = [];
+    globalThis.fetch = (async (input: RequestInfo | URL, init?: RequestInit) => {
+      const url = String(input);
+      const headers = init?.headers as Record<string, string> | undefined;
+      seen.push({ url, authorization: headers?.Authorization, redirect: init?.redirect });
+      if (url.endsWith("/dashboard/billing/subscription")) {
+        return new Response(JSON.stringify({ data: { hard_limit_usd: "20" } }), { status: 200 });
+      }
+      return new Response(JSON.stringify({ data: {
+        total_granted: "20000000",
+        total_used: "5000000",
+        total_available: "15000000",
+        expires_at: "2026-08-01T00:00:00Z",
+      } }), { status: 200 });
+    }) as typeof fetch;
+
+    const result = await fetchProviderQuotaReports(a6apiOnlyConfig(), true);
+
+    expect(result.reports).toHaveLength(1);
+    expect(result.reports[0]?.source).toBe("a6api:billing");
+    expect(result.reports[0]?.quota.customWindows).toEqual([{
+      label: "API credits ($15.00 of $20.00 remaining)",
+      percent: 25,
+    }]);
+    expect(seen.map(row => row.url).sort()).toEqual([
+      "https://api.a6api.com/api/usage/token/",
+      "https://api.a6api.com/dashboard/billing/subscription",
+    ]);
+    expect(seen.every(row => row.authorization === "Bearer a6api-secret")).toBe(true);
+    expect(seen.every(row => row.redirect === "error")).toBe(true);
+  });
+
+  test("A6API quota never sends API keys to a non-canonical base URL", async () => {
+    const seen: string[] = [];
+    globalThis.fetch = (async (input: RequestInfo | URL) => {
+      seen.push(String(input));
+      return new Response("unexpected", { status: 500 });
+    }) as typeof fetch;
+
+    const result = await fetchProviderQuotaReports(a6apiOnlyConfig("https://attacker.example/v1"), true);
+
+    expect(result.reports).toEqual([]);
+    expect(seen).toEqual([]);
+  });
+
+  test("A6API quota drops incomplete or zero-limit billing payloads", async () => {
+    globalThis.fetch = (async (input: RequestInfo | URL) => {
+      const url = String(input);
+      return new Response(JSON.stringify(url.includes("subscription")
+        ? { data: { hard_limit_usd: 0 } }
+        : { data: { total_granted: 100, total_used: 20, total_available: 80 } }), { status: 200 });
+    }) as typeof fetch;
+
+    const result = await fetchProviderQuotaReports(a6apiOnlyConfig(), true);
+
+    expect(result.reports).toEqual([]);
+  });
+
+  test.each([
+    { total_used: -1, total_available: 101 },
+    { total_used: 1, total_available: -1 },
+    { total_used: 80, total_available: 80 },
+    { total_used: 20, total_available: 70 },
+  ])("A6API quota drops malformed usage totals", async usage => {
+    globalThis.fetch = (async (input: RequestInfo | URL) => {
+      const url = String(input);
+      return new Response(JSON.stringify(url.includes("subscription")
+        ? { data: { hard_limit_usd: 10 } }
+        : { data: { total_granted: 100, ...usage } }), { status: 200 });
+    }) as typeof fetch;
+
+    const result = await fetchProviderQuotaReports(a6apiOnlyConfig(), true);
+
+    expect(result.reports).toEqual([]);
+  });
+
+  test("A6API quota applies reconciliation tolerance relative to sub-unit grants", async () => {
+    globalThis.fetch = (async (input: RequestInfo | URL) => new Response(JSON.stringify(
+      String(input).includes("subscription")
+        ? { data: { hard_limit_usd: 10 } }
+        : { data: { total_granted: 0.1, total_used: 0.05, total_available: 0.0500000005 } },
+    ), { status: 200 })) as typeof fetch;
+
+    const result = await fetchProviderQuotaReports(a6apiOnlyConfig(), true);
+
+    expect(result.reports).toEqual([]);
+  });
+
+  test("A6API quota accepts equivalent canonical HTTPS URLs only", async () => {
+    const seen: string[] = [];
+    globalThis.fetch = (async (input: RequestInfo | URL) => {
+      seen.push(String(input));
+      return new Response(JSON.stringify(String(input).includes("subscription")
+        ? { data: { hard_limit_usd: 10 } }
+        : { data: { total_granted: 100, total_used: 25, total_available: 75 } }), { status: 200 });
+    }) as typeof fetch;
+
+    const canonicalUrls = [
+      "https://api.a6api.com",
+      "https://api.a6api.com/v1",
+      "https://API.A6API.COM:443/v1/",
+    ];
+    for (const baseUrl of canonicalUrls) {
+      const result = await fetchProviderQuotaReports(a6apiOnlyConfig(baseUrl), true);
+      expect(result.reports).toHaveLength(1);
+    }
+    const credentialedUrl = "https://user" + "@api.a6api.com/v1";
+    const credentialed = await fetchProviderQuotaReports(a6apiOnlyConfig(credentialedUrl), true);
+
+    expect(credentialed.reports).toEqual([]);
+    expect(seen).toHaveLength(canonicalUrls.length * 2);
+  });
+
+  test("malformed API-key fields do not break unrelated quota reports", async () => {
+    globalThis.fetch = (async (input: RequestInfo | URL) => new Response(JSON.stringify(
+      String(input).includes("subscription")
+        ? { data: { hard_limit_usd: 10 } }
+        : { data: { total_granted: 100, total_used: 25, total_available: 75 } },
+    ), { status: 200 })) as typeof fetch;
+    const config = a6apiOnlyConfig();
+    config.providers.broken = {
+      adapter: "openai-chat",
+      authMode: "key",
+      baseUrl: "https://example.com/v1",
+      apiKey: 42,
+    } as unknown as OcxConfig["providers"][string];
+
+    const result = await fetchProviderQuotaReports(config, true);
+
+    expect(result.reports).toHaveLength(1);
+    expect(result.reports[0]?.provider).toBe("a6api");
+  });
+
+  test("A6API quota is detected by canonical base URL for custom provider names", async () => {
+    globalThis.fetch = (async (input: RequestInfo | URL) => new Response(JSON.stringify(
+      String(input).includes("subscription")
+        ? { data: { hard_limit_usd: 10 } }
+        : { data: { total_granted: 100, total_used: 25, total_available: 75 } },
+    ), { status: 200 })) as typeof fetch;
+    const config = a6apiOnlyConfig();
+    config.defaultProvider = "my-a6";
+    config.providers = { "my-a6": config.providers.a6api! };
+
+    const result = await fetchProviderQuotaReports(config, true);
+
+    expect(result.reports[0]?.provider).toBe("my-a6");
+    expect(result.reports[0]?.quota.customWindows?.[0]?.percent).toBe(25);
+  });
+
+  test("A6API quota cache follows the active API key", async () => {
+    const authorizations: string[] = [];
+    globalThis.fetch = (async (input: RequestInfo | URL, init?: RequestInit) => {
+      const headers = init?.headers as Record<string, string> | undefined;
+      authorizations.push(headers?.Authorization ?? "");
+      const secondAccount = headers?.Authorization === "Bearer second-account-key";
+      return new Response(JSON.stringify(String(input).includes("subscription")
+        ? { data: { hard_limit_usd: secondAccount ? 30 : 10 } }
+        : { data: { total_granted: 100, total_used: 20, total_available: 80 } }), { status: 200 });
+    }) as typeof fetch;
+    const config = a6apiOnlyConfig();
+
+    const first = await fetchProviderQuotaReports(config);
+    config.providers.a6api!.apiKey = "second-account-key";
+    const second = await fetchProviderQuotaReports(config);
+
+    expect(first.reports[0]?.quota.customWindows?.[0]?.label).toContain("of $10.00 remaining");
+    expect(second.reports[0]?.quota.customWindows?.[0]?.label).toContain("of $30.00 remaining");
+    expect(authorizations).toContain("Bearer second-account-key");
+  });
+
+  test("A6API quota drops a last-good row after a terminal-invalid refresh", async () => {
+    let malformed = false;
+    globalThis.fetch = (async (input: RequestInfo | URL) => new Response(JSON.stringify(
+      String(input).includes("subscription")
+        ? { data: { hard_limit_usd: 10 } }
+        : { data: malformed
+          ? { total_granted: 100, total_used: 20, total_available: 70 }
+          : { total_granted: 100, total_used: 20, total_available: 80 } },
+    ), { status: 200 })) as typeof fetch;
+    const config = a6apiOnlyConfig();
+
+    const valid = await fetchProviderQuotaReports(config, true);
+    malformed = true;
+    const invalid = await fetchProviderQuotaReports(config, true);
+
+    expect(valid.reports).toHaveLength(1);
+    expect(invalid.reports).toEqual([]);
+  });
+
+  test("A6API quota preserves a last-good row after a transient server failure", async () => {
+    let unavailable = false;
+    globalThis.fetch = (async (input: RequestInfo | URL) => {
+      if (unavailable) return new Response("unavailable", { status: 503 });
+      return new Response(JSON.stringify(String(input).includes("subscription")
+        ? { data: { hard_limit_usd: 10 } }
+        : { data: { total_granted: 100, total_used: 20, total_available: 80 } }), { status: 200 });
+    }) as typeof fetch;
+    const config = a6apiOnlyConfig();
+
+    const valid = await fetchProviderQuotaReports(config, true);
+    unavailable = true;
+    const transientFailure = await fetchProviderQuotaReports(config, true);
+
+    expect(transientFailure.reports).toEqual(valid.reports);
+  });
+
   test("Kimi quota never sends OAuth credentials to a non-canonical base URL", async () => {
     await saveCredential("kimi", { access: "kimi-access-secret", refresh: "kimi-refresh-secret", expires: Date.now() + 3600_000 });
     const seen: string[] = [];