diff --git a/docs-site/src/content/docs/guides/providers.md b/docs-site/src/content/docs/guides/providers.md
index f8d13cbe87..3a3276c602 100644
--- a/docs-site/src/content/docs/guides/providers.md
+++ b/docs-site/src/content/docs/guides/providers.md
@@ -655,13 +655,22 @@ their matching bars. OpenCodex does not reconstruct dollar caps from local usage
 provider using a non-canonical `baseUrl` is never sent the key for this probe.
 
 **Z.AI GLM Coding Plan quota.** The `zai`, `glm`, `glm-cn`, and `zhipu-bigmodel-coding`
-presets read `GET /api/monitor/usage/quota/limit` with the configured key as a Bearer token
-and do not follow redirects. The probe runs against the region the provider points at:
+presets read `GET /api/monitor/usage/quota/limit` and do not follow redirects. The probe
+runs against the region the provider points at:
 `api.z.ai` (bare or `/api/coding/paas/v4`) or `open.bigmodel.cn` (bare,
-`/api/coding/paas/v4`, or the OpenAI Responses endpoint `/api/v1`). The response's `limits`
-rows fill the utilization bars: `TOKENS_LIMIT` / `CREDIT_LIMIT` rows with `unit` 3 /
-`number` 5 fill the 5-hour bar and `unit` 6 / `number` 1 the weekly bar, while
-`TIME_LIMIT` rows fill the monthly MCP bar. The v2 coding-plan protocol reports the
-monthly MCP row; the newer protocol does not, so the monthly bar renders only when that
-row is present. A provider using a non-canonical `baseUrl` is never sent the key for this
-probe.
+`/api/coding/paas/v4`, or the OpenAI Responses endpoint `/api/v1`).
+
+Authentication differs by region: `api.z.ai` takes the key as a Bearer token, while
+`open.bigmodel.cn` expects the key directly in `Authorization` with no scheme prefix and
+rejects a Bearer header. The response's `limits` rows fill the utilization bars:
+`TOKENS_LIMIT` / `CREDIT_LIMIT` rows with `unit` 3 / `number` 5 fill the 5-hour bar and
+`unit` 6 / `number` 1 the weekly bar.
+
+`TIME_LIMIT` rows are **not** model quota and are ignored. They are the shared monthly
+MCP call allowance for Web Search, Web Reader, and Zread, so treating them as a model
+window would let a spent web-search budget read as exhausted model capacity in
+quota-aware account ranking. A plan that reports only `TIME_LIMIT` rows therefore shows
+no quota bars rather than a fabricated one, and windows the plan does not report stay
+absent instead of rendering as 0%.
+
+A provider using a non-canonical `baseUrl` is never sent the key for this probe.
diff --git a/src/providers/quota.ts b/src/providers/quota.ts
index e27bb29a31..3335679e63 100644
--- a/src/providers/quota.ts
+++ b/src/providers/quota.ts
@@ -104,7 +104,23 @@ export function setProviderQuotaBeforePublishForTests(
   providerQuotaBeforePublishForTests = hook;
 }
 const TERMINAL_QUOTA_FAILURE = Symbol("terminal-quota-failure");
-type ProviderQuotaProbeResult = ProviderQuotaReport | null | typeof TERMINAL_QUOTA_FAILURE;
+/**
+ * The probe succeeded and the upstream authoritatively reported NO model-quota windows.
+ *
+ * Distinct from `null`, which means "this probe told us nothing" and deliberately preserves
+ * the last-good row for up to 30 minutes. Collapsing the two would let a stale report outlive
+ * the authoritative answer that replaced it: a GLM plan whose payload carries only MCP
+ * `TIME_LIMIT` rows has no model windows, and the dashboard and quota-aware routing must stop
+ * showing the previous token windows rather than keep them for another half hour.
+ *
+ * Suppression is shared with `TERMINAL_QUOTA_FAILURE`; only the reason differs.
+ */
+const AUTHORITATIVE_EMPTY_QUOTA = Symbol("authoritative-empty-quota");
+type ProviderQuotaProbeResult =
+  | ProviderQuotaReport
+  | null
+  | typeof TERMINAL_QUOTA_FAILURE
+  | typeof AUTHORITATIVE_EMPTY_QUOTA;
 
 export interface ProviderQuotaReport {
   provider: string;
@@ -636,10 +652,19 @@ async function fetchClineQuota(provider: string, config: OcxProviderConfig): Pro
  * same rows `CREDIT_LIMIT`) and `TIME_LIMIT` rows. `TOKENS_LIMIT`/`CREDIT_LIMIT`
  * rows carry the window length as `unit`/`number`: unit 3 is hours (number 5 →
  * the rolling five-hour window), unit 6 is weeks (number 1 → the weekly
- * window). `TIME_LIMIT` rows are the monthly MCP tool budget (Web Search / Web
- * Reader / Zread). Every row's `percentage` is the consumed share (falling
+ * window). Every row's `percentage` is the consumed share (falling
  * back to `currentValue`/`usage` when absent) and `nextResetTime` (unix ms)
  * the window reset.
+ *
+ * `TIME_LIMIT` rows are deliberately ignored (issue #1168). They are the shared
+ * monthly MCP *call* allowance for Web Search / Web Reader / Zread — not a
+ * model-token budget — and `ProviderQuota.monthlyPercent` is consumed as a
+ * model-capacity signal: `headroomOf()` in `src/oauth/account-quota-rank.ts`
+ * takes the MAX across every window, so a user who spent their MCP search
+ * allowance would be ranked as having no model capacity left, and the dashboard
+ * would draw a full monthly bar for a plan whose model tokens are untouched.
+ * A payload carrying only `TIME_LIMIT` rows therefore reports no quota at all,
+ * which is the honest answer rather than a fabricated one.
  */
 export function parseZaiQuotaLimits(data: Record<string, unknown> | null): ProviderQuota | null {
   const limits = Array.isArray(data?.limits) ? data.limits as unknown[] : null;
@@ -649,6 +674,9 @@ export function parseZaiQuotaLimits(data: Record<string, unknown> | null): Provi
   for (const raw of limits) {
     const row = asRecord(raw);
     if (!row) continue;
+    // Gate on row type before deriving a percentage: an MCP row must not even
+    // contribute a parsed value to a model-quota report.
+    if (row.type !== "TOKENS_LIMIT" && row.type !== "CREDIT_LIMIT") continue;
     const resetAt = normalizeResetAt(row.nextResetTime);
     let percent = normalizePercent(row.percentage);
     if (percent === undefined) {
@@ -659,21 +687,15 @@ export function parseZaiQuotaLimits(data: Record<string, unknown> | null): Provi
       }
     }
     if (percent === undefined) continue;
-    if (row.type === "TOKENS_LIMIT" || row.type === "CREDIT_LIMIT") {
-      const unit = toFiniteNumber(row.unit);
-      const number = toFiniteNumber(row.number);
-      if (unit === 3 && number === 5) {
-        quota.fiveHourPercent = percent;
-        if (resetAt !== undefined) quota.fiveHourResetAt = resetAt;
-        windows += 1;
-      } else if (unit === 6 && number === 1) {
-        quota.weeklyPercent = percent;
-        if (resetAt !== undefined) quota.weeklyResetAt = resetAt;
-        windows += 1;
-      }
-    } else if (row.type === "TIME_LIMIT") {
-      quota.monthlyPercent = percent;
-      if (resetAt !== undefined) quota.monthlyResetAt = resetAt;
+    const unit = toFiniteNumber(row.unit);
+    const number = toFiniteNumber(row.number);
+    if (unit === 3 && number === 5) {
+      quota.fiveHourPercent = percent;
+      if (resetAt !== undefined) quota.fiveHourResetAt = resetAt;
+      windows += 1;
+    } else if (unit === 6 && number === 1) {
+      quota.weeklyPercent = percent;
+      if (resetAt !== undefined) quota.weeklyResetAt = resetAt;
       windows += 1;
     }
   }
@@ -715,9 +737,16 @@ function parseZaiQuotaLegacyFields(data: Record<string, unknown> | null): Provid
 
 /**
  * Fetches the Z.AI GLM Coding Plan quota — on whichever region the provider
- * points at (api.z.ai or open.bigmodel.cn). Authenticates with the API key as
- * a Bearer token per Z.AI's API reference. The `limits` array shape is
+ * points at (api.z.ai or open.bigmodel.cn). The `limits` array shape is
  * preferred; older field-name payloads fall back to the legacy parser.
+ *
+ * Authentication differs by host (issue #1168). `api.z.ai` takes the API key as
+ * a Bearer token per Z.AI's API reference; `open.bigmodel.cn` expects the key
+ * directly in `Authorization` with no scheme prefix and answers a Bearer header
+ * with an auth error, which is why BigModel Coding Plan quota never rendered.
+ * The host is already canonicalized by `isCanonicalZaiBaseUrl` above and
+ * `redirect: "error"` stays set, so the bare key cannot travel to a lookalike
+ * host or follow a redirect off-origin.
  */
 async function fetchZaiQuota(provider: string, config: OcxProviderConfig): Promise<ProviderQuotaProbeResult> {
   if (!isCanonicalZaiBaseUrl(config.baseUrl)) return null;
@@ -727,8 +756,9 @@ async function fetchZaiQuota(provider: string, config: OcxProviderConfig): Promi
   const monitorHost = normalized === ZAI_BASE_URL || normalized === `${ZAI_BASE_URL}/api/coding/paas/v4`
     ? ZAI_BASE_URL
     : ZAI_CN_BASE_URL;
+  const authorization = monitorHost === ZAI_CN_BASE_URL ? apiKey : `Bearer ${apiKey}`;
   const response = await fetch(`${monitorHost}/api/monitor/usage/quota/limit`, {
-    headers: { Accept: "application/json", Authorization: `Bearer ${apiKey}` },
+    headers: { Accept: "application/json", Authorization: authorization },
     redirect: "error",
     signal: AbortSignal.timeout(REQUEST_TIMEOUT_MS),
   });
@@ -740,10 +770,16 @@ async function fetchZaiQuota(provider: string, config: OcxProviderConfig): Promi
   const body = asRecord(await readQuotaJson(response));
   if (!body || body.success === false) return null;
   const data = asRecord(body.data) ?? body;
-  const quota = Array.isArray(data?.limits)
-    ? parseZaiQuotaLimits(data)
-    : parseZaiQuotaLegacyFields(data);
-  return quota ? report(provider, "zai:quota-limit", quota) : null;
+  if (Array.isArray(data?.limits)) {
+    const quota = parseZaiQuotaLimits(data);
+    // A well-formed `limits[]` we fully understood is authoritative even when it yields no
+    // model window — for example a plan reporting only the monthly MCP `TIME_LIMIT` row.
+    // Returning `null` here would preserve the previous token windows for up to 30 minutes
+    // and keep quota-aware routing acting on a report the provider has already superseded.
+    return quota ? report(provider, "zai:quota-limit", quota) : AUTHORITATIVE_EMPTY_QUOTA;
+  }
+  const legacy = parseZaiQuotaLegacyFields(data);
+  return legacy ? report(provider, "zai:quota-limit", legacy) : null;
 }
 
 /**
@@ -2308,9 +2344,18 @@ export async function fetchProviderQuotaReports(config: OcxConfig, forceRefresh
         maybeFetchProviderQuota(name, provider, config, forceRefresh, prefetchedCodexSnapshot)
       )),
     );
-    const fresh = probeResults.filter((item): item is ProviderQuotaReport => item !== null && item !== TERMINAL_QUOTA_FAILURE);
+    const fresh = probeResults.filter((item): item is ProviderQuotaReport => (
+      item !== null && item !== TERMINAL_QUOTA_FAILURE && item !== AUTHORITATIVE_EMPTY_QUOTA
+    ));
+    // Both sentinels suppress the previous row. A terminal failure means the response was
+    // invalid; an authoritative empty means the response was valid and said there are no
+    // model windows. Either way the old row is no longer true, which is what separates them
+    // from `null` (told us nothing — keep the last-good row).
     const terminalFailures = new Set(
-      Object.keys(config.providers).filter((_, index) => probeResults[index] === TERMINAL_QUOTA_FAILURE),
+      Object.keys(config.providers).filter((_, index) => (
+        probeResults[index] === TERMINAL_QUOTA_FAILURE
+        || probeResults[index] === AUTHORITATIVE_EMPTY_QUOTA
+      )),
     );
     await providerQuotaBeforePublishForTests?.();
     let commitKey: string | null = null;
diff --git a/tests/provider-quota.test.ts b/tests/provider-quota.test.ts
index 5eef964306..ad3a6edbdd 100644
--- a/tests/provider-quota.test.ts
+++ b/tests/provider-quota.test.ts
@@ -979,9 +979,11 @@ describe("fetchProviderQuotaReports", () => {
       fiveHourResetAt: 1789000000000,
       weeklyPercent: 52,
       weeklyResetAt: 1789600000000,
-      monthlyPercent: 12.3,
-      monthlyResetAt: 1789000000000,
     });
+    // The TIME_LIMIT row is the MCP call allowance, not a model-token window, so it
+    // must not surface as monthly model quota (issue #1168).
+    expect(result.reports[0]?.quota.monthlyPercent).toBeUndefined();
+    expect(result.reports[0]?.quota.monthlyResetAt).toBeUndefined();
     expect(seen).toHaveLength(1);
     expect(seen[0]?.url).toBe("https://api.z.ai/api/monitor/usage/quota/limit");
     expect(seen[0]?.authorization).toBe("Bearer zai-secret");
@@ -1017,11 +1019,12 @@ describe("fetchProviderQuotaReports", () => {
     expect(result.reports[0]?.quota).toMatchObject({
       fiveHourPercent: 20,
       weeklyPercent: 52,
-      monthlyPercent: 7.5,
     });
+    expect(result.reports[0]?.quota.monthlyPercent).toBeUndefined();
     expect(seen).toHaveLength(1);
     expect(seen[0]?.url).toBe("https://open.bigmodel.cn/api/monitor/usage/quota/limit");
-    expect(seen[0]?.authorization).toBe("Bearer zai-secret");
+    // BigModel takes the raw key; a Bearer prefix is rejected upstream (issue #1168).
+    expect(seen[0]?.authorization).toBe("zai-secret");
     expect(seen[0]?.redirect).toBe("error");
   });
 
@@ -1078,11 +1081,11 @@ describe("fetchProviderQuotaReports", () => {
     expect(result.reports[0]?.quota).toMatchObject({
       fiveHourPercent: 30,
       weeklyPercent: 60,
-      monthlyPercent: 9.5,
     });
+    expect(result.reports[0]?.quota.monthlyPercent).toBeUndefined();
     expect(seen).toHaveLength(1);
     expect(seen[0]?.url).toBe("https://open.bigmodel.cn/api/monitor/usage/quota/limit");
-    expect(seen[0]?.authorization).toBe("Bearer zai-secret");
+    expect(seen[0]?.authorization).toBe("zai-secret");
   });
 
   test("Z.AI quota treats an unsuccessful payload as a no-report", async () => {
@@ -1127,7 +1130,7 @@ describe("fetchProviderQuotaReports", () => {
     expect(seen).toEqual([]);
   });
 
-  test("Z.AI quota ignores token rows whose window length does not match", async () => {
+  test("Z.AI quota reports nothing when only unmatched token rows and an MCP row remain", async () => {
     globalThis.fetch = (async () => new Response(JSON.stringify({
       success: true,
       data: {
@@ -1141,10 +1144,10 @@ describe("fetchProviderQuotaReports", () => {
 
     const result = await fetchProviderQuotaReports(keyQuotaConfig("zai", "https://api.z.ai/api/coding/paas/v4"), true);
 
-    expect(result.reports).toHaveLength(1);
-    expect(result.reports[0]?.quota).toMatchObject({ monthlyPercent: 12.3 });
-    expect(result.reports[0]?.quota.fiveHourPercent).toBeUndefined();
-    expect(result.reports[0]?.quota.weeklyPercent).toBeUndefined();
+    // Neither token row matches a known window length and the TIME_LIMIT row is the MCP
+    // allowance, so there is no model-quota evidence at all. Reporting no quota is the
+    // honest outcome; previously the MCP row alone produced a monthly model bar.
+    expect(result.reports).toEqual([]);
   });
 
   test("Z.AI quota does not fall back to legacy fields when limits is present but empty", async () => {
@@ -1158,7 +1161,7 @@ describe("fetchProviderQuotaReports", () => {
     expect(result.reports).toEqual([]);
   });
 
-  test("Z.AI quota renders a real v2 coding-plan response (monthly MCP TIME_LIMIT)", async () => {
+  test("Z.AI quota ignores the monthly MCP TIME_LIMIT row in a real v2 response", async () => {
     // Sanitized live response captured from the /api/monitor/usage/quota/limit probe
     // (level=max, v2 protocol): the TIME_LIMIT row is the 30-day MCP tool budget
     // (search-prime / web-reader / zread), independent of the token windows.
@@ -1181,9 +1184,99 @@ describe("fetchProviderQuotaReports", () => {
       fiveHourResetAt: 1787056863927,
       weeklyPercent: 20,
       weeklyResetAt: 1787641095989,
-      monthlyPercent: 0,
-      monthlyResetAt: 1788073095998,
     });
+    // The MCP allowance is untouched here (percentage 0) while the five-hour model
+    // window is fully consumed. Reporting the MCP row as monthly model quota is what
+    // issue #1168 removes: headroomOf() takes the MAX across windows, so an exhausted
+    // MCP budget would otherwise be read as exhausted model capacity.
+    expect(result.reports[0]?.quota.monthlyPercent).toBeUndefined();
+    expect(result.reports[0]?.quota.monthlyResetAt).toBeUndefined();
+  });
+
+  test("a later MCP-only refresh clears the cached Z.AI model windows", async () => {
+    // Sequential forced refreshes. The first returns real token windows, so a last-good row
+    // exists; the second is a SUCCESSFUL response that authoritatively reports no model
+    // windows. Treating that as a transient failure would preserve the stale token windows
+    // for up to 30 minutes, so the dashboard and quota-aware routing would keep acting on a
+    // report the provider has already superseded.
+    let call = 0;
+    globalThis.fetch = (async () => {
+      call += 1;
+      const limits = call === 1
+        ? [
+          { type: "TOKENS_LIMIT", unit: 3, number: 5, percentage: 40, nextResetTime: 1789000000000 },
+          { type: "TOKENS_LIMIT", unit: 6, number: 1, percentage: 52, nextResetTime: 1789600000000 },
+        ]
+        : [
+          { type: "TIME_LIMIT", unit: 5, number: 1, usage: 100, currentValue: 20, remaining: 80, percentage: 20, nextResetTime: 1788921262994 },
+        ];
+      return new Response(JSON.stringify({ success: true, data: { limits, level: "lite" } }), { status: 200 });
+    }) as typeof fetch;
+
+    const cfg = keyQuotaConfig("zhipu-bigmodel-coding", "https://open.bigmodel.cn/api/coding/paas/v4", "zai-secret");
+
+    const first = await fetchProviderQuotaReports(cfg, true);
+    expect(first.reports).toHaveLength(1);
+    expect(first.reports[0]?.quota).toMatchObject({ fiveHourPercent: 40, weeklyPercent: 52 });
+
+    const second = await fetchProviderQuotaReports(cfg, true);
+    expect(second.reports).toEqual([]);
+  });
+
+  test("Z.AI quota reports no model window when the payload carries only an MCP TIME_LIMIT row", async () => {
+    // A BigModel V1 Lite plan whose MCP allowance is fully spent but whose model tokens
+    // are untouched. Before issue #1168 this produced monthlyPercent: 100, and because
+    // headroomOf() in src/oauth/account-quota-rank.ts takes the MAX across every window,
+    // the account ranked as having ZERO model headroom — a healthy account demoted, or
+    // skipped, over a spent web-search budget.
+    globalThis.fetch = (async () => new Response(JSON.stringify({
+      success: true,
+      data: {
+        limits: [
+          { type: "TIME_LIMIT", unit: 5, number: 1, usage: 100, currentValue: 100, remaining: 0, percentage: 100, nextResetTime: 1788921262994,
+            usageDetails: [{ modelCode: "search-prime", usage: 60 }, { modelCode: "web-reader", usage: 40 }, { modelCode: "zread", usage: 0 }] },
+        ],
+        level: "lite",
+      },
+    }), { status: 200 })) as typeof fetch;
+
+    const result = await fetchProviderQuotaReports(
+      keyQuotaConfig("zhipu-bigmodel-coding", "https://open.bigmodel.cn/api/coding/paas/v4", "zai-secret"),
+      true,
+    );
+
+    expect(result.reports).toEqual([]);
+  });
+
+  test("Z.AI quota omits absent windows rather than reporting them as zero", async () => {
+    // Real V1 Lite shape from issue #1168: one five-hour token window plus the MCP row.
+    // Weekly and monthly must be ABSENT, not 0 — a synthesized 0 would draw a
+    // full-capacity weekly bar for a plan that never reported one.
+    globalThis.fetch = (async () => new Response(JSON.stringify({
+      code: 200,
+      msg: "操作成功",
+      success: true,
+      data: {
+        limits: [
+          { type: "TIME_LIMIT", unit: 5, number: 1, usage: 100, currentValue: 0, remaining: 100, percentage: 0, nextResetTime: 1788921262994,
+            usageDetails: [{ modelCode: "search-prime", usage: 0 }, { modelCode: "web-reader", usage: 0 }, { modelCode: "zread", usage: 0 }] },
+          { type: "TOKENS_LIMIT", unit: 3, number: 5, percentage: 1, nextResetTime: 1786626122911 },
+        ],
+        level: "lite",
+      },
+    }), { status: 200 })) as typeof fetch;
+
+    const result = await fetchProviderQuotaReports(
+      keyQuotaConfig("zhipu-bigmodel-coding", "https://open.bigmodel.cn/api/coding/paas/v4", "zai-secret"),
+      true,
+    );
+
+    expect(result.reports).toHaveLength(1);
+    expect(result.reports[0]?.quota).toMatchObject({ fiveHourPercent: 1, fiveHourResetAt: 1786626122911 });
+    expect(result.reports[0]?.quota.weeklyPercent).toBeUndefined();
+    expect(result.reports[0]?.quota.weeklyResetAt).toBeUndefined();
+    expect(result.reports[0]?.quota.monthlyPercent).toBeUndefined();
+    expect(result.reports[0]?.quota.monthlyResetAt).toBeUndefined();
   });
 
   test("Z.AI quota renders a real new-protocol response without the monthly MCP row", async () => {