diff --git a/packages/vscode/src/quotaProviders.test.ts b/packages/vscode/src/quotaProviders.test.ts
index 784d5bc5..09429a1b 100644
--- a/packages/vscode/src/quotaProviders.test.ts
+++ b/packages/vscode/src/quotaProviders.test.ts
@@ -17,6 +17,7 @@ const AUTH = JSON.stringify({
   crof: { key: 'test-token' },
   neuralwatt: { key: 'test-token' },
   'opencode-go': { key: 'test-token' },
+  openrouter: { key: 'test-token' },
   'zai-coding-plan': { key: 'test-token' },
   deepseek: { key: 'test-token' },
   hyper: { key: 'test-token' },
@@ -114,6 +115,180 @@ describe('OpenCode Go quota provider (VS Code parity)', () => {
   });
 });
 
+describe('OpenRouter quota provider (VS Code parity)', () => {
+  const documentedPayload = {
+    data: {
+      label: 'test-key',
+      usage: 3.17561396,
+      usage_daily: 0.0000018,
+      usage_weekly: 0.0000018,
+      usage_monthly: 3.17561396,
+      limit: 30,
+      limit_remaining: 29.9999982,
+      limit_reset: 'daily',
+      is_free_tier: true,
+      is_management_key: false,
+      include_byok_in_limit: false,
+      byok_usage: 0,
+    },
+  };
+
+  test('reads the documented key endpoint and emits the current reset window', async () => {
+    let requestedUrl = '';
+    let requestInit: RequestInit | undefined;
+    globalThis.fetch = (async (url: string, init?: RequestInit) => {
+      requestedUrl = url;
+      requestInit = init;
+      return mockResponse(documentedPayload);
+    }) as typeof fetch;
+
+    const result = await fetchQuotaForProvider('openrouter');
+
+    assert.equal(requestedUrl, 'https://openrouter.ai/api/v1/key');
+    assert.equal(requestedUrl.includes('/api/v1/credits'), false);
+    assert.equal(new Headers(requestInit?.headers).get('Authorization'), 'Bearer test-token');
+    assert.equal(new Headers(requestInit?.headers).get('Accept-Encoding'), 'identity');
+    assert.ok(requestInit?.signal instanceof AbortSignal);
+    assert.deepEqual(Object.keys(result.usage!.windows), ['daily']);
+    assert.equal(result.usage!.windows.daily!.windowSeconds, 86400);
+    assert.equal(result.usage!.windows.daily!.valueLabel, '$0.00 / $30.00');
+    assert.ok(typeof result.usage!.windows.daily!.resetAt === 'number');
+  });
+
+  test('maps an unlimited null-limit key to a monthly spent window', async () => {
+    stubFetchReturning(() => Promise.resolve(mockResponse({
+      data: { limit: null, limit_remaining: null, limit_reset: null, usage_monthly: 12.5, is_management_key: false },
+    })));
+
+    const result = await fetchQuotaForProvider('openrouter');
+
+    assert.equal(result.ok, true);
+    assert.deepEqual(Object.keys(result.usage!.windows), ['monthly']);
+    assert.equal(result.usage!.windows.monthly!.usedPercent, null);
+    assert.equal(result.usage!.windows.monthly!.windowSeconds, 30 * 86400);
+    assert.equal(result.usage!.windows.monthly!.valueLabel, '$12.50 spent');
+    assert.ok(typeof result.usage!.windows.monthly!.resetAt === 'number');
+  });
+
+  test('maps a lifetime cap to a credits window without reset metadata', async () => {
+    stubFetchReturning(() => Promise.resolve(mockResponse({
+      data: { limit: 30, limit_remaining: 25, limit_reset: null, usage_monthly: 5 },
+    })));
+
+    const result = await fetchQuotaForProvider('openrouter');
+    const window = result.usage!.windows.credits;
+
+    assert.ok(window);
+    assert.equal(window!.windowSeconds, null);
+    assert.equal(window!.resetAt, null);
+  });
+
+  test('maps an unrecognized reset period to a credits window', async () => {
+    stubFetchReturning(() => Promise.resolve(mockResponse({
+      data: { limit: 30, limit_remaining: 25, limit_reset: 'yearly', usage_monthly: 5 },
+    })));
+
+    const result = await fetchQuotaForProvider('openrouter');
+
+    assert.ok(result.usage!.windows.credits);
+    assert.equal(result.usage!.windows.credits!.windowSeconds, null);
+    assert.equal(result.usage!.windows.credits!.resetAt, null);
+  });
+
+  test('clamps percent at 100 while leaving the money label unclamped', async () => {
+    stubFetchReturning(() => Promise.resolve(mockResponse({
+      data: { limit: 30, limit_remaining: -1, limit_reset: 'monthly', usage_monthly: 31 },
+    })));
+
+    const result = await fetchQuotaForProvider('openrouter');
+    const window = result.usage!.windows.monthly;
+
+    assert.equal(window!.usedPercent, 100);
+    assert.equal(window!.valueLabel, '$31.00 / $30.00');
+  });
+
+  test('uses a weekly window and derives its reset on Monday UTC', async () => {
+    stubFetchReturning(() => Promise.resolve(mockResponse({
+      data: { limit: 30, limit_remaining: 25, limit_reset: 'weekly', usage_monthly: 5 },
+    })));
+
+    const result = await fetchQuotaForProvider('openrouter');
+    const window = result.usage!.windows.weekly;
+
+    assert.ok(window);
+    assert.equal(window!.windowSeconds, 604800);
+    assert.equal(new Date(window!.resetAt!).getUTCDay(), 1);
+  });
+
+  test('rejects management keys with an inference-key error', async () => {
+    stubFetchReturning(() => Promise.resolve(mockResponse({ data: { is_management_key: true } })));
+
+    const result = await fetchQuotaForProvider('openrouter');
+
+    assert.equal(result.ok, false);
+    assert.equal(result.configured, true);
+    assert.equal(result.usage, null);
+    assert.equal(result.error, 'Management key configured — quota needs an inference API key');
+  });
+
+  for (const status of [401, 403]) {
+    test(`maps HTTP ${status} to session expiry`, async () => {
+      stubFetchFailing(async () => ({}), { ok: false, status });
+
+      const result = await fetchQuotaForProvider('openrouter');
+
+      assert.equal(result.ok, false);
+      assert.equal(result.error, 'Session expired — please re-authenticate with OpenRouter');
+    });
+  }
+
+  test('reports invalid JSON as a parse failure', async () => {
+    globalThis.fetch = (async () => ({
+      ok: true,
+      status: 200,
+      json: async () => { throw new SyntaxError('Unexpected token'); },
+    }) as unknown as Response) as typeof fetch;
+
+    const result = await fetchQuotaForProvider('openrouter');
+
+    assert.equal(result.ok, false);
+    assert.equal(result.error, 'Invalid response from provider');
+  });
+
+  test('normalizes timeout failures', async () => {
+    stubFetchReturning(() => Promise.reject(new DOMException('Timed out', 'TimeoutError')));
+
+    const result = await fetchQuotaForProvider('openrouter');
+
+    assert.equal(result.ok, false);
+    assert.equal(result.error, 'Request timed out');
+  });
+
+  test('rejects a response without usable quota data', async () => {
+    stubFetchReturning(() => Promise.resolve(mockResponse({ data: { limit: 30, limit_remaining: null } })));
+
+    const result = await fetchQuotaForProvider('openrouter');
+
+    assert.equal(result.ok, false);
+    assert.equal(result.configured, true);
+    assert.equal(result.usage, null);
+    assert.equal(result.error, 'No quota data in response');
+  });
+
+  for (const payload of [{ data: {} }, { data: null }]) {
+    test(`rejects ${JSON.stringify(payload)} without quota data`, async () => {
+      stubFetchReturning(() => Promise.resolve(mockResponse(payload)));
+
+      const result = await fetchQuotaForProvider('openrouter');
+
+      assert.equal(result.ok, false);
+      assert.equal(result.configured, true);
+      assert.equal(result.usage, null);
+      assert.equal(result.error, 'No quota data in response');
+    });
+  }
+});
+
 
 describe('Crof quota provider (VS Code parity)', () => {
   test('reports credits balance as valueLabel with null percent', async () => {
diff --git a/packages/vscode/src/quotaProviders.ts b/packages/vscode/src/quotaProviders.ts
index 962c7103..7deb6129 100644
--- a/packages/vscode/src/quotaProviders.ts
+++ b/packages/vscode/src/quotaProviders.ts
@@ -1933,6 +1933,28 @@ const fetchCursorQuota = async (): Promise<ProviderResult> => {
   } catch (error) { return buildResult({ providerId: 'cursor', providerName: 'Cursor', ok: false, configured: true, error: error instanceof Error ? error.message : 'Request failed' }); }
 };
 
+const openRouterResetAt = (period: string | null, nowMs: number): number | null => {
+  const now = new Date(nowMs);
+  const year = now.getUTCFullYear();
+  const month = now.getUTCMonth();
+  const day = now.getUTCDate();
+
+  if (period === 'daily') return Date.UTC(year, month, day + 1);
+  if (period === 'weekly') {
+    const daysUntilMonday = ((8 - now.getUTCDay()) % 7) || 7;
+    return Date.UTC(year, month, day + daysUntilMonday);
+  }
+  if (period === 'monthly') return Date.UTC(year, month + 1, 1);
+  return null;
+};
+
+const PERIOD_SECONDS = { daily: 86400, weekly: 604800, monthly: 30 * 86400 };
+type OpenRouterPeriod = keyof typeof PERIOD_SECONDS;
+
+const isOpenRouterPeriod = (value: unknown): value is OpenRouterPeriod => (
+  typeof value === 'string' && Object.prototype.hasOwnProperty.call(PERIOD_SECONDS, value)
+);
+
 const fetchOpenRouterQuota = async (): Promise<ProviderResult> => {
   const auth = readAuthFile();
   const entry = normalizeAuthEntry(getAuthEntry(auth, ['openrouter'])) as Record<string, unknown> | null;
@@ -1948,13 +1970,16 @@ const fetchOpenRouterQuota = async (): Promise<ProviderResult> => {
     });
   }
 
+  const timeoutSignal = AbortSignal.timeout(15_000);
+
   try {
-    const response = await fetch('https://openrouter.ai/api/v1/credits', {
+    const response = await fetch('https://openrouter.ai/api/v1/key', {
       method: 'GET',
       headers: {
         Authorization: `Bearer ${apiKey}`,
-        'Content-Type': 'application/json',
+        'Accept-Encoding': 'identity',
       },
+      signal: timeoutSignal,
     });
 
     if (!response.ok) {
@@ -1963,20 +1988,86 @@ const fetchOpenRouterQuota = async (): Promise<ProviderResult> => {
         providerName: 'OpenRouter',
         ok: false,
         configured: true,
-        error: `API error: ${response.status}`,
+        error: response.status === 401 || response.status === 403
+          ? 'Session expired — please re-authenticate with OpenRouter'
+          : `API error: ${response.status}`,
       });
     }
 
-    const payload = await response.json() as Record<string, unknown>;
-    const credits = payload.data as Record<string, unknown> | undefined;
-    const totalCredits = toNumber(credits?.total_credits);
-    const totalUsage = toNumber(credits?.total_usage);
-    const remaining = totalCredits !== null && totalUsage !== null
-      ? Math.max(0, totalCredits - totalUsage)
-      : null;
-    let valueLabel: string | null = null;
-    if (remaining !== null && totalUsage !== null) {
-      valueLabel = `$${formatMoney(remaining)} left · $${formatMoney(totalUsage)} spent`;
+    const payload = await response.json() as unknown;
+    const dataContainer = asObject(payload);
+    const data = asObject(dataContainer?.data);
+    if (data === null) {
+      return buildResult({
+        providerId: 'openrouter',
+        providerName: 'OpenRouter',
+        ok: false,
+        configured: true,
+        error: 'No quota data in response',
+      });
+    }
+
+    if (data.is_management_key === true) {
+      return buildResult({
+        providerId: 'openrouter',
+        providerName: 'OpenRouter',
+        ok: false,
+        configured: true,
+        error: 'Management key configured — quota needs an inference API key',
+      });
+    }
+
+    const limit = toNumber(data.limit);
+    const limitRemaining = toNumber(data.limit_remaining);
+    if (limit !== null && limitRemaining === null) {
+      return buildResult({
+        providerId: 'openrouter',
+        providerName: 'OpenRouter',
+        ok: false,
+        configured: true,
+        error: 'No quota data in response',
+      });
+    }
+
+    const usageMonthly = toNumber(data.usage_monthly);
+    if (limit === null && usageMonthly === null) {
+      return buildResult({
+        providerId: 'openrouter',
+        providerName: 'OpenRouter',
+        ok: false,
+        configured: true,
+        error: 'No quota data in response',
+      });
+    }
+
+    const nowMs = Date.now();
+    let windowKey: string;
+    let windowSeconds: number | null;
+    let resetAt: number | null;
+    let usedPercent: number | null;
+    let valueLabel: string;
+
+    if (limit === null) {
+      windowKey = 'monthly';
+      windowSeconds = PERIOD_SECONDS.monthly;
+      resetAt = openRouterResetAt('monthly', nowMs);
+      usedPercent = null;
+      valueLabel = `$${formatMoney(usageMonthly)} spent`;
+    } else {
+      const used = Math.max(0, limit - (limitRemaining ?? 0));
+      const percent = limit > 0 ? (used / limit) * 100 : null;
+      usedPercent = percent === null ? null : Math.min(100, percent);
+      valueLabel = `$${formatMoney(used)} / $${formatMoney(limit)}`;
+
+      if (isOpenRouterPeriod(data.limit_reset)) {
+        windowKey = data.limit_reset;
+        windowSeconds = PERIOD_SECONDS[data.limit_reset];
+        resetAt = openRouterResetAt(data.limit_reset, nowMs);
+      } else {
+        windowKey = 'credits';
+        windowSeconds = null;
+        resetAt = null;
+      }
     }
 
     return buildResult({
@@ -1986,22 +2077,28 @@ const fetchOpenRouterQuota = async (): Promise<ProviderResult> => {
       configured: true,
       usage: {
         windows: {
-          credits: toUsageWindow({
-            usedPercent: null,
-            windowSeconds: null,
-            resetAt: null,
+          [windowKey]: toUsageWindow({
+            usedPercent,
+            windowSeconds,
+            resetAt,
             valueLabel,
           }),
         },
       },
     });
   } catch (error) {
+    const isTimeout = error instanceof DOMException && (error.name === 'TimeoutError' || (error.name === 'AbortError' && timeoutSignal.aborted));
+    const isParseError = error instanceof SyntaxError;
     return buildResult({
       providerId: 'openrouter',
       providerName: 'OpenRouter',
       ok: false,
       configured: true,
-      error: error instanceof Error ? error.message : 'Request failed',
+      error: isTimeout
+        ? 'Request timed out'
+        : isParseError
+          ? 'Invalid response from provider'
+          : error instanceof Error ? error.message : 'Request failed',
     });
   }
 };
diff --git a/packages/web/server/lib/quota/DOCUMENTATION.md b/packages/web/server/lib/quota/DOCUMENTATION.md
index fdfe118f..0a8d10e9 100644
--- a/packages/web/server/lib/quota/DOCUMENTATION.md
+++ b/packages/web/server/lib/quota/DOCUMENTATION.md
@@ -128,6 +128,16 @@ snapshot carries `entitlement`, `remaining`, `unlimited`, and
 - When entitlement/remaining are unusable, fall back to `100 - percent_remaining`.
 - Snapshots other than `premium_interactions` (legacy annual plans) yield zero windows.
 
+## OpenRouter key semantics
+
+OpenRouter quota reads `GET https://openrouter.ai/api/v1/key`, which is documented as callable with any valid API key. `GET /api/v1/credits` is documented as "Management key required" and is not used. Calling `/credits` with a normal inference key has been observed to return HTTP 200 with `{total_credits:0, total_usage:0}` rather than an error; this behavior is not documented and is why the old implementation silently rendered "$0.00 left · $0.00 spent". A `/credits` fallback for unlimited keys would render the same zeros, so unlimited keys report `usage_monthly` instead.
+
+The documented `limit`, `limit_remaining`, and `limit_reset` fields are present and null on unlimited keys; null means unlimited, never missing data. For a limited key, window usage is `limit - limit_remaining`, not `usage`: `usage` is all-time and measures a different axis from the current reset window. Pairing `usage` with the current limit produces a wrong number. `limit_remaining` is server-computed and already honors `include_byok_in_limit`, so `byok_*` fields are ignored.
+
+Unlimited keys report `usage_monthly` in a `monthly` window with no percent. `limit_reset` is a period string (`daily`, `weekly`, `monthly`, or null), not a timestamp; `resetAt` is derived from the documented midnight-UTC boundaries, with weeks starting Monday. A set `limit` with a null `limit_reset` is a lifetime cap and maps to the `credits` window with no reset.
+
+Keep `packages/web/server/lib/quota/providers/openrouter.js` and `packages/vscode/src/quotaProviders.ts` in sync, as with the Kimi and Copilot providers; the VS Code extension duplicates this parsing logic rather than importing the web provider.
+
 ## Notes for contributors
 - Keep provider IDs stable; clients use them directly.
 - Avoid adding alias-based dispatch in `fetchQuotaForProvider`; dispatch currently expects exact provider IDs.
diff --git a/packages/web/server/lib/quota/providers/openrouter.js b/packages/web/server/lib/quota/providers/openrouter.js
index f82ed45a..499b0a01 100644
--- a/packages/web/server/lib/quota/providers/openrouter.js
+++ b/packages/web/server/lib/quota/providers/openrouter.js
@@ -5,12 +5,30 @@ import {
   buildResult,
   toUsageWindow,
   toNumber,
+  asObject,
   formatMoney
 } from '../utils/index.js';
 
 export const providerId = 'openrouter';
 export const providerName = 'OpenRouter';
-const aliases = ['openrouter'];
+export const aliases = ['openrouter'];
+const OPENROUTER_QUOTA_URL = 'https://openrouter.ai/api/v1/key';
+const PERIOD_SECONDS = { daily: 86400, weekly: 604800, monthly: 30 * 86400 };
+
+export const resolveResetAt = (limitReset, nowMs) => {
+  const now = new Date(nowMs);
+  const y = now.getUTCFullYear();
+  const m = now.getUTCMonth();
+  const d = now.getUTCDate();
+
+  if (limitReset === 'daily') return Date.UTC(y, m, d + 1);
+  if (limitReset === 'weekly') {
+    const dow = now.getUTCDay();
+    return Date.UTC(y, m, d + ((8 - dow) % 7 || 7));
+  }
+  if (limitReset === 'monthly') return Date.UTC(y, m + 1, 1);
+  return null;
+};
 
 export const isConfigured = () => {
   const auth = readAuthFile();
@@ -33,13 +51,16 @@ export const fetchQuota = async () => {
     });
   }
 
+  const timeoutSignal = AbortSignal.timeout(15_000);
+
   try {
-    const response = await fetch('https://openrouter.ai/api/v1/credits', {
+    const response = await fetch(OPENROUTER_QUOTA_URL, {
       method: 'GET',
       headers: {
         Authorization: `Bearer ${apiKey}`,
-        'Content-Type': 'application/json'
-      }
+        'Accept-Encoding': 'identity'
+      },
+      signal: timeoutSignal
     });
 
     if (!response.ok) {
@@ -48,45 +69,119 @@ export const fetchQuota = async () => {
         providerName,
         ok: false,
         configured: true,
-        error: `API error: ${response.status}`
+        error: response.status === 401 || response.status === 403
+          ? 'Session expired — please re-authenticate with OpenRouter'
+          : `API error: ${response.status}`
       });
     }
 
     const payload = await response.json();
-    const credits = payload?.data ?? {};
-    const totalCredits = toNumber(credits.total_credits);
-    const totalUsage = toNumber(credits.total_usage);
-    const remaining = totalCredits !== null && totalUsage !== null
-      ? Math.max(0, totalCredits - totalUsage)
-      : null;
-    let valueLabel = null;
-    if (remaining !== null && totalUsage !== null) {
-      valueLabel = `$${formatMoney(remaining)} left · $${formatMoney(totalUsage)} spent`;
+    const data = asObject(payload?.data);
+
+    if (data === null) {
+      return buildResult({
+        providerId,
+        providerName,
+        ok: false,
+        configured: true,
+        error: 'No quota data in response'
+      });
     }
 
-    const windows = {
-      credits: toUsageWindow({
-        usedPercent: null,
-        windowSeconds: null,
-        resetAt: null,
-        valueLabel
-      })
-    };
+    if (data.is_management_key === true) {
+      return buildResult({
+        providerId,
+        providerName,
+        ok: false,
+        configured: true,
+        error: 'Management key configured — quota needs an inference API key'
+      });
+    }
+
+    const limit = toNumber(data.limit);
+    const limitRemaining = toNumber(data.limit_remaining);
+    if (limit !== null && limitRemaining === null) {
+      return buildResult({
+        providerId,
+        providerName,
+        ok: false,
+        configured: true,
+        error: 'No quota data in response'
+      });
+    }
+
+    const usageMonthly = toNumber(data.usage_monthly);
+    if (limit === null && usageMonthly === null) {
+      return buildResult({
+        providerId,
+        providerName,
+        ok: false,
+        configured: true,
+        error: 'No quota data in response'
+      });
+    }
+
+    const nowMs = Date.now();
+    let windowKey;
+    let windowSeconds;
+    let resetAt;
+    let usedPercent;
+    let valueLabel;
+
+    if (limit === null) {
+      windowKey = 'monthly';
+      windowSeconds = PERIOD_SECONDS.monthly;
+      resetAt = resolveResetAt('monthly', nowMs);
+      usedPercent = null;
+      valueLabel = `$${formatMoney(usageMonthly)} spent`;
+    } else {
+      const used = Math.max(0, limit - limitRemaining);
+      const percent = limit > 0 ? (used / limit) * 100 : null;
+      usedPercent = percent === null ? null : Math.min(100, percent);
+      valueLabel = `$${formatMoney(used)} / $${formatMoney(limit)}`;
+
+      if (Object.hasOwn(PERIOD_SECONDS, data.limit_reset)) {
+        windowKey = data.limit_reset;
+        windowSeconds = PERIOD_SECONDS[data.limit_reset];
+        resetAt = resolveResetAt(data.limit_reset, nowMs);
+      } else {
+        windowKey = 'credits';
+        windowSeconds = null;
+        resetAt = null;
+      }
+    }
 
     return buildResult({
       providerId,
       providerName,
       ok: true,
       configured: true,
-      usage: { windows }
+      usage: {
+        windows: {
+          [windowKey]: toUsageWindow({
+            usedPercent,
+            windowSeconds,
+            resetAt,
+            valueLabel
+          })
+        }
+      }
     });
   } catch (error) {
+    const isTimeout = error instanceof DOMException && (
+      error.name === 'TimeoutError' || (error.name === 'AbortError' && timeoutSignal.aborted)
+    );
+    const isParseError = error instanceof SyntaxError;
     return buildResult({
       providerId,
       providerName,
       ok: false,
       configured: true,
-      error: error instanceof Error ? error.message : 'Request failed'
+      error: isTimeout
+        ? 'Request timed out'
+        : isParseError
+          ? 'Invalid response from provider'
+          : (error instanceof Error ? error.message : 'Request failed')
     });
   }
 };
diff --git a/packages/web/server/lib/quota/providers/openrouter.test.js b/packages/web/server/lib/quota/providers/openrouter.test.js
new file mode 100644
index 00000000..42474654
--- /dev/null
+++ b/packages/web/server/lib/quota/providers/openrouter.test.js
@@ -0,0 +1,330 @@
+import { afterEach, describe, expect, it, vi } from 'vitest';
+
+vi.mock('../../opencode/auth.js', () => ({
+  readAuthFile: () => ({ openrouter: { key: 'test-token' } }),
+}));
+
+import { fetchQuota, resolveResetAt } from './openrouter.js';
+
+afterEach(() => {
+  vi.unstubAllGlobals();
+});
+
+const mockResponse = (body, init = {}) => ({
+  ok: true,
+  status: 200,
+  json: async () => body,
+  ...init,
+});
+
+// Documented payload shape from https://openrouter.ai/docs/api_reference/limits
+const DOCUMENTED_PAYLOAD = {
+  data: {
+    label: 'Default',
+    limit: 30,
+    limit_remaining: 25,
+    limit_reset: 'monthly',
+    include_byok_in_limit: false,
+    usage: 5,
+    usage_daily: 1,
+    usage_weekly: 3,
+    usage_monthly: 5,
+    byok_usage: 0,
+    byok_usage_daily: 0,
+    byok_usage_weekly: 0,
+    byok_usage_monthly: 0,
+    is_free_tier: false,
+    is_management_key: false,
+    is_provisioning_key: false,
+    creator_user_id: 'user-fixture',
+    expires_at: null,
+    rate_limit: null
+  }
+};
+
+const expectMonthlyReset = (resetAt) => {
+  expect(resetAt).toEqual(expect.any(Number));
+  const resetDate = new Date(resetAt);
+  expect(resetDate.getUTCDate()).toBe(1);
+  expect(resetDate.getUTCHours()).toBe(0);
+  expect(resetAt - Date.now()).toBeGreaterThan(0);
+  expect(resetAt - Date.now()).toBeLessThanOrEqual(31 * 86400 * 1000);
+};
+
+describe('OpenRouter quota provider', () => {
+  it('builds a monthly window from the documented payload', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse(DOCUMENTED_PAYLOAD)));
+
+    const result = await fetchQuota();
+    const window = result.usage.windows.monthly;
+
+    expect(result.ok).toBe(true);
+    expect(result.providerId).toBe('openrouter');
+    expect(window.usedPercent).toBeCloseTo(16.6667, 3);
+    expect(window.valueLabel).toBe('$5.00 / $30.00');
+    expect(window.windowSeconds).toBe(30 * 86400);
+    expectMonthlyReset(window.resetAt);
+  });
+
+  it('uses the daily window and preserves the observed funded-key values', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse({
+      data: {
+        usage: 3.17561396,
+        usage_daily: 0.0000018,
+        usage_weekly: 0.0000018,
+        usage_monthly: 3.17561396,
+        limit: 30,
+        limit_remaining: 29.9999982,
+        limit_reset: 'daily',
+        is_free_tier: true,
+        is_management_key: false,
+        include_byok_in_limit: false,
+        byok_usage: 0
+      }
+    })));
+
+    const result = await fetchQuota();
+    const window = result.usage.windows.daily;
+
+    expect(window).toBeDefined();
+    expect(window.windowSeconds).toBe(86400);
+    expect(window.valueLabel).toBe('$0.00 / $30.00');
+    expect(window.usedPercent).toBeLessThan(0.001);
+    expect(window.resetAt % 86400000).toBe(0);
+    expect(window.resetAt - Date.now()).toBeGreaterThan(0);
+    expect(window.resetAt - Date.now()).toBeLessThanOrEqual(86400000);
+  });
+
+  it('builds a monthly unlimited window from null limit fields', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse({
+      data: {
+        limit: null,
+        limit_remaining: null,
+        limit_reset: null,
+        usage_monthly: 3.17561396,
+        is_management_key: false
+      }
+    })));
+
+    const result = await fetchQuota();
+    const window = result.usage.windows.monthly;
+
+    expect(window.usedPercent).toBeNull();
+    expect(window.valueLabel).toBe('$3.18 spent');
+    expect(window.windowSeconds).toBe(30 * 86400);
+    expectMonthlyReset(window.resetAt);
+  });
+
+  it('uses a credits window for a lifetime cap', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse({
+      data: { limit: 30, limit_remaining: 25, limit_reset: null, usage_monthly: 5 }
+    })));
+
+    const result = await fetchQuota();
+    const window = result.usage.windows.credits;
+
+    expect(window).toBeDefined();
+    expect(window.resetAt).toBeNull();
+    expect(window.windowSeconds).toBeNull();
+  });
+
+  it('uses a credits window for an unrecognized reset period', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse({
+      data: { limit: 30, limit_remaining: 25, limit_reset: 'yearly', usage_monthly: 5 }
+    })));
+
+    const result = await fetchQuota();
+    const window = result.usage.windows.credits;
+
+    expect(window).toBeDefined();
+    expect(window.resetAt).toBeNull();
+    expect(window.windowSeconds).toBeNull();
+  });
+
+  it('builds a weekly window from a weekly limit', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse({
+      data: { limit: 30, limit_remaining: 25, limit_reset: 'weekly', usage_monthly: 5 }
+    })));
+
+    const result = await fetchQuota();
+    const window = result.usage.windows.weekly;
+
+    expect(window).toBeDefined();
+    expect(window.windowSeconds).toBe(604800);
+    expect(new Date(window.resetAt).getUTCDay()).toBe(1);
+    expect(window.resetAt - Date.now()).toBeGreaterThan(0);
+    expect(window.resetAt - Date.now()).toBeLessThanOrEqual(7 * 86400 * 1000);
+  });
+
+  it('ignores BYOK usage when calculating the quota label and percent', async () => {
+    const withByokPayload = {
+      ...DOCUMENTED_PAYLOAD,
+      data: {
+        ...DOCUMENTED_PAYLOAD.data,
+        include_byok_in_limit: true,
+        byok_usage_monthly: 100,
+        byok_usage: 100
+      }
+    };
+    const fetchMock = vi.fn()
+      .mockResolvedValueOnce(mockResponse(DOCUMENTED_PAYLOAD))
+      .mockResolvedValueOnce(mockResponse(withByokPayload));
+    vi.stubGlobal('fetch', fetchMock);
+
+    const withoutByok = await fetchQuota();
+    const withByok = await fetchQuota();
+
+    expect(withByok.usage.windows.monthly.valueLabel)
+      .toBe(withoutByok.usage.windows.monthly.valueLabel);
+    expect(withByok.usage.windows.monthly.usedPercent)
+      .toBe(withoutByok.usage.windows.monthly.usedPercent);
+  });
+
+  it('rejects management keys with a specific error', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse({
+      data: { is_management_key: true }
+    })));
+
+    const result = await fetchQuota();
+
+    expect(result.ok).toBe(false);
+    expect(result.configured).toBe(true);
+    expect(result.usage).toBeNull();
+    expect(result.error).toBe('Management key configured — quota needs an inference API key');
+  });
+
+  it.each([401, 403])('maps %s to a session-expired error', async (status) => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue({ ok: false, status }));
+
+    const result = await fetchQuota();
+
+    expect(result.ok).toBe(false);
+    expect(result.error).toBe('Session expired — please re-authenticate with OpenRouter');
+  });
+
+  it('reports invalid-response on JSON parse failure', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue({
+      ok: true,
+      status: 200,
+      json: async () => { throw new SyntaxError('Unexpected token'); },
+    }));
+
+    const result = await fetchQuota();
+
+    expect(result.ok).toBe(false);
+    expect(result.error).toBe('Invalid response from provider');
+  });
+
+  it('reports a normalized timeout error', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockRejectedValue(new DOMException('The operation timed out.', 'TimeoutError')));
+
+    const result = await fetchQuota();
+
+    expect(result.ok).toBe(false);
+    expect(result.error).toBe('Request timed out');
+  });
+
+  it('returns no-quota-data when data is missing', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse({})));
+
+    const result = await fetchQuota();
+
+    expect(result.ok).toBe(false);
+    expect(result.configured).toBe(true);
+    expect(result.error).toBe('No quota data in response');
+    expect(result.usage).toBeNull();
+  });
+
+  it('returns no-quota-data when data is empty', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse({ data: {} })));
+
+    const result = await fetchQuota();
+
+    expect(result.ok).toBe(false);
+    expect(result.configured).toBe(true);
+    expect(result.error).toBe('No quota data in response');
+    expect(result.usage).toBeNull();
+  });
+
+  it.each([null, []])('returns no-quota-data when data is %s', async (data) => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse({ data })));
+
+    const result = await fetchQuota();
+
+    expect(result.ok).toBe(false);
+    expect(result.configured).toBe(true);
+    expect(result.usage).toBeNull();
+    expect(result.error).toBe('No quota data in response');
+  });
+
+  it('returns no-quota-data when a limit has no remaining value', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse({
+      data: { limit: 30, limit_remaining: null, usage_monthly: 5 }
+    })));
+
+    const result = await fetchQuota();
+
+    expect(result.ok).toBe(false);
+    expect(result.error).toBe('No quota data in response');
+  });
+
+  it('keeps a zero limit valid with a null percent', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse({
+      data: { limit: 0, limit_remaining: 0, limit_reset: 'monthly', usage_monthly: 0 }
+    })));
+
+    const result = await fetchQuota();
+    const window = result.usage.windows.monthly;
+
+    expect(result.ok).toBe(true);
+    expect(window.usedPercent).toBeNull();
+    expect(window.valueLabel).toBe('$0.00 / $0.00');
+  });
+
+  it('requests the key endpoint and never the credits endpoint', async () => {
+    const fetchMock = vi.fn().mockResolvedValue(mockResponse(DOCUMENTED_PAYLOAD));
+    vi.stubGlobal('fetch', fetchMock);
+
+    await fetchQuota();
+
+    const requestedUrl = fetchMock.mock.calls[0][0];
+    expect(requestedUrl).toBe('https://openrouter.ai/api/v1/key');
+    expect(requestedUrl).not.toContain('/api/v1/credits');
+  });
+
+  it('resolves daily reset at the next UTC day across year boundaries', () => {
+    expect(resolveResetAt('daily', Date.UTC(2024, 11, 31, 23, 59))).toBe(Date.UTC(2025, 0, 1));
+  });
+
+  it('resolves weekly reset from Sunday to the next Monday', () => {
+    expect(resolveResetAt('weekly', Date.UTC(2024, 0, 7, 12))).toBe(Date.UTC(2024, 0, 8));
+  });
+
+  it('resolves weekly reset from Monday to the following Monday', () => {
+    expect(resolveResetAt('weekly', Date.UTC(2024, 0, 8, 12))).toBe(Date.UTC(2024, 0, 15));
+  });
+
+  it('resolves weekly reset from Wednesday to the next Monday', () => {
+    expect(resolveResetAt('weekly', Date.UTC(2024, 0, 10, 12))).toBe(Date.UTC(2024, 0, 15));
+  });
+
+  it('resolves monthly reset from January 31 to February 1', () => {
+    expect(resolveResetAt('monthly', Date.UTC(2024, 0, 31, 12))).toBe(Date.UTC(2024, 1, 1));
+  });
+
+  it('resolves monthly reset across December to January', () => {
+    expect(resolveResetAt('monthly', Date.UTC(2024, 11, 31, 23, 59))).toBe(Date.UTC(2025, 0, 1));
+  });
+
+  it('clamps percent at 100 while leaving the money label unclamped', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse({
+      data: { limit: 30, limit_remaining: -1, limit_reset: 'monthly', usage_monthly: 31 }
+    })));
+
+    const result = await fetchQuota();
+    const window = result.usage.windows.monthly;
+
+    expect(window.usedPercent).toBe(100);
+    expect(window.valueLabel).toBe('$31.00 / $30.00');
+  });
+});