diff --git a/open-sse/services/crofUsageFetcher.ts b/open-sse/services/crofUsageFetcher.ts
new file mode 100644
index 0000000000..869aa27303
--- /dev/null
+++ b/open-sse/services/crofUsageFetcher.ts
@@ -0,0 +1,182 @@
+/**
+ * crofUsageFetcher.ts — CrofAI Usage Fetcher
+ *
+ * Implements QuotaFetcher for the crof provider (quotaPreflight.ts + quotaMonitor.ts).
+ *
+ * CrofAI exposes `GET https://crof.ai/usage_api/` (Bearer auth) returning:
+ *
+ *   { "usable_requests": 450 | null, "credits": 12.3456 }
+ *
+ * - `usable_requests`: requests left today on a subscription plan; `null` if
+ *   the account is on pay-as-you-go (credits only).
+ * - `credits`: USD-denominated credit balance.
+ *
+ * Mapping to QuotaInfo:
+ * - Subscription account (usable_requests is a number):
+ *     used = 0, total = usable_requests, percentUsed = usable_requests > 0 ? 0 : 1
+ *   We do not know the daily allotment from the API response, so we surface
+ *   "remaining" only and only block (percentUsed = 1) when the bucket hits 0.
+ * - Pay-as-you-go (usable_requests null):
+ *     percentUsed = credits > 0 ? 0 : 1
+ *   Same blocking semantics — reserve account-switching for the credits-empty
+ *   case rather than guessing a burn rate.
+ *
+ * Preflight is OFF by default (per quotaPreflight.isQuotaPreflightEnabled).
+ * Monitor display is always available once the fetcher is registered.
+ *
+ * Cache: 60s in-memory, keyed by connectionId.
+ *
+ * Registration: call registerCrofUsageFetcher() once at server startup.
+ */
+
+import { registerQuotaFetcher, type QuotaInfo } from "./quotaPreflight.ts";
+import { registerMonitorFetcher } from "./quotaMonitor.ts";
+
+const CROF_USAGE_URL = "https://crof.ai/usage_api/";
+const CACHE_TTL_MS = 60_000;
+
+/** Crof-specific quota info: surfaces both raw signals so the UI can show them. */
+export interface CrofQuota extends QuotaInfo {
+  /** Requests left today (null when not on a subscription plan). */
+  usableRequests: number | null;
+  /** USD credit balance. */
+  credits: number;
+}
+
+interface CacheEntry {
+  quota: CrofQuota;
+  fetchedAt: number;
+}
+
+const quotaCache = new Map<string, CacheEntry>();
+
+const _cacheCleanup = setInterval(() => {
+  const now = Date.now();
+  for (const [key, entry] of quotaCache) {
+    if (now - entry.fetchedAt > CACHE_TTL_MS * 5) {
+      quotaCache.delete(key);
+    }
+  }
+}, 5 * 60_000);
+
+if (typeof _cacheCleanup === "object" && "unref" in _cacheCleanup) {
+  (_cacheCleanup as { unref?: () => void }).unref?.();
+}
+
+// ─── Helpers ─────────────────────────────────────────────────────────────────
+
+function toNumber(value: unknown): number | null {
+  if (typeof value === "number" && Number.isFinite(value)) return value;
+  if (typeof value === "string") {
+    const parsed = parseFloat(value);
+    if (Number.isFinite(parsed)) return parsed;
+  }
+  return null;
+}
+
+function toRecord(value: unknown): Record<string, unknown> {
+  return value && typeof value === "object" && !Array.isArray(value)
+    ? (value as Record<string, unknown>)
+    : {};
+}
+
+function getApiKey(connection: Record<string, unknown> | undefined): string | null {
+  const raw = connection?.apiKey;
+  if (typeof raw === "string" && raw.trim().length > 0) return raw.trim();
+  return null;
+}
+
+// ─── Response parser ─────────────────────────────────────────────────────────
+
+export function parseCrofUsageResponse(data: unknown): CrofQuota | null {
+  const obj = toRecord(data);
+  if (Object.keys(obj).length === 0) return null;
+
+  const usableRequestsRaw = obj["usable_requests"];
+  const usableRequests =
+    usableRequestsRaw === null || usableRequestsRaw === undefined
+      ? null
+      : toNumber(usableRequestsRaw);
+
+  const credits = toNumber(obj["credits"]) ?? 0;
+
+  // Block (percentUsed = 1) only when the active bucket hits zero. Otherwise
+  // surface the raw counts and leave switching decisions to the caller.
+  let percentUsed = 0;
+  if (usableRequests !== null) {
+    percentUsed = usableRequests > 0 ? 0 : 1;
+  } else {
+    percentUsed = credits > 0 ? 0 : 1;
+  }
+
+  return {
+    used: 0,
+    total: usableRequests ?? 0,
+    percentUsed,
+    resetAt: null,
+    usableRequests,
+    credits,
+  };
+}
+
+// ─── Core fetcher ────────────────────────────────────────────────────────────
+
+export async function fetchCrofUsage(
+  connectionId: string,
+  connection?: Record<string, unknown>
+): Promise<QuotaInfo | null> {
+  const cached = quotaCache.get(connectionId);
+  if (cached && Date.now() - cached.fetchedAt < CACHE_TTL_MS) {
+    return cached.quota;
+  }
+
+  const apiKey = getApiKey(connection);
+  if (!apiKey) {
+    // No credentials available — fail open, never block requests on this.
+    return null;
+  }
+
+  try {
+    const response = await fetch(CROF_USAGE_URL, {
+      method: "GET",
+      headers: {
+        Authorization: `Bearer ${apiKey}`,
+        Accept: "application/json",
+      },
+      signal: AbortSignal.timeout(8_000),
+    });
+
+    if (!response.ok) {
+      if (response.status === 401 || response.status === 403) {
+        quotaCache.delete(connectionId);
+      }
+      return null;
+    }
+
+    const data = await response.json();
+    const quota = parseCrofUsageResponse(data);
+    if (!quota) return null;
+
+    quotaCache.set(connectionId, { quota, fetchedAt: Date.now() });
+    return quota;
+  } catch {
+    // Network error / timeout — fail open
+    return null;
+  }
+}
+
+/** Force-invalidate the cache for a connection (e.g., after a manual top-up). */
+export function invalidateCrofUsageCache(connectionId: string): void {
+  quotaCache.delete(connectionId);
+}
+
+// ─── Registration ────────────────────────────────────────────────────────────
+
+/**
+ * Register the CrofAI usage fetcher with both the preflight and monitor systems.
+ * Call this once at server startup.
+ */
+export function registerCrofUsageFetcher(): void {
+  registerQuotaFetcher("crof", fetchCrofUsage);
+  registerMonitorFetcher("crof", fetchCrofUsage);
+}
diff --git a/open-sse/services/usage.ts b/open-sse/services/usage.ts
index 6ddafcad4e..8805ff9947 100644
--- a/open-sse/services/usage.ts
+++ b/open-sse/services/usage.ts
@@ -392,6 +392,111 @@ async function getMiniMaxUsage(apiKey: string, provider: "minimax" | "minimax-cn
   };
 }
 
+// CrofAI surfaces a tiny endpoint with two signals:
+//   GET https://crof.ai/usage_api/  →  { usable_requests: number|null, credits: number }
+// `usable_requests` is the daily request bucket on a subscription plan; `null`
+// for pay-as-you-go. `credits` is the USD credit balance. We surface both as
+// quotas so the Limits & Quotas page can render whichever the account uses.
+async function getCrofUsage(apiKey: string) {
+  if (!apiKey) {
+    return { message: "CrofAI API key not available. Add a key to view usage." };
+  }
+
+  let response: Response;
+  try {
+    response = await fetch("https://crof.ai/usage_api/", {
+      method: "GET",
+      headers: {
+        Authorization: `Bearer ${apiKey}`,
+        Accept: "application/json",
+      },
+    });
+  } catch (error) {
+    return { message: `CrofAI connected. Unable to fetch usage: ${(error as Error).message}` };
+  }
+
+  const rawText = await response.text();
+
+  if (response.status === 401 || response.status === 403) {
+    return { message: "CrofAI connected. The API key was rejected by /usage_api/." };
+  }
+
+  if (!response.ok) {
+    return { message: `CrofAI connected. /usage_api/ returned HTTP ${response.status}.` };
+  }
+
+  let payload: JsonRecord = {};
+  if (rawText) {
+    try {
+      payload = toRecord(JSON.parse(rawText));
+    } catch {
+      return { message: "CrofAI connected. Unable to parse /usage_api/ response." };
+    }
+  }
+
+  const usableRequestsRaw = payload["usable_requests"];
+  const usableRequests =
+    usableRequestsRaw === null || usableRequestsRaw === undefined
+      ? null
+      : toNumber(usableRequestsRaw, 0);
+  const credits = toNumber(payload["credits"], 0);
+
+  const quotas: Record<string, UsageQuota> = {};
+
+  if (usableRequests !== null) {
+    // CrofAI's /usage_api/ returns only the remaining count; the daily
+    // allotment is not exposed. CrofAI Pro plan = 1,000 requests/day per
+    // their pricing page, so use that as the baseline total. If the user
+    // is on a plan with a higher cap we widen the total to whatever they
+    // currently report so we never compute a negative `used`.
+    // Without this, total=0 makes the dashboard's percentage formula read
+    // 0% (interpreted as "depleted" → red) even on a fresh bucket.
+    const CROF_DAILY_BASELINE = 1000;
+    const remaining = Math.max(0, usableRequests);
+    const total = Math.max(CROF_DAILY_BASELINE, remaining);
+    const used = Math.max(0, total - remaining);
+
+    // CrofAI also does not return a reset timestamp and the docs only say
+    // "requests left today". The Crof.ai dashboard shows the daily bucket
+    // resetting at ~05:00 UTC (verified against the live countdown on
+    // 2026-04-25), so synthesize the next 05:00 UTC instant to match.
+    // Swap for a real field if Crof ever exposes one.
+    const now = new Date();
+    const RESET_HOUR_UTC = 5;
+    const todayResetMs = Date.UTC(
+      now.getUTCFullYear(),
+      now.getUTCMonth(),
+      now.getUTCDate(),
+      RESET_HOUR_UTC
+    );
+    const nextResetMs =
+      todayResetMs > now.getTime() ? todayResetMs : todayResetMs + 24 * 60 * 60 * 1000;
+    const nextResetIso = new Date(nextResetMs).toISOString();
+
+    quotas["Requests Today"] = {
+      used,
+      total,
+      remaining,
+      resetAt: nextResetIso,
+      unlimited: false,
+      displayName: `Requests Today: ${remaining} left`,
+    };
+  }
+
+  // Credits are an open balance — render as unlimited so the UI shows the
+  // dollar value rather than a misleading 0/0 bar.
+  quotas["Credits"] = {
+    used: 0,
+    total: 0,
+    remaining: 0,
+    resetAt: null,
+    unlimited: true,
+    displayName: `Credits: $${credits.toFixed(4)}`,
+  };
+
+  return { quotas };
+}
+
 async function getGlmUsage(apiKey: string, providerSpecificData?: Record<string, unknown>) {
   const quotaUrl = getGlmQuotaUrl(providerSpecificData);
 
@@ -510,6 +615,8 @@ export async function getUsageForProvider(connection) {
     case "minimax":
     case "minimax-cn":
       return await getMiniMaxUsage(apiKey, provider);
+    case "crof":
+      return await getCrofUsage(apiKey);
     case "cursor":
       return await getCursorUsage(accessToken);
     case "bailian-coding-plan":
diff --git a/src/lib/usage/providerLimits.ts b/src/lib/usage/providerLimits.ts
index a7fe0f76a0..5ca5b3523e 100644
--- a/src/lib/usage/providerLimits.ts
+++ b/src/lib/usage/providerLimits.ts
@@ -43,7 +43,7 @@ interface ProviderConnectionLike {
   backoffLevel?: number;
 }
 
-const PROVIDER_LIMITS_APIKEY_PROVIDERS = new Set(["glm", "glmt", "minimax", "minimax-cn"]);
+const PROVIDER_LIMITS_APIKEY_PROVIDERS = new Set(["glm", "glmt", "minimax", "minimax-cn", "crof"]);
 const DEFAULT_PROVIDER_LIMITS_SYNC_INTERVAL_MINUTES = 70;
 const PROVIDER_LIMITS_AUTO_SYNC_SETTING_KEY = "provider_limits_auto_sync_last_run";
 
diff --git a/src/shared/constants/providers.ts b/src/shared/constants/providers.ts
index 4bd9bfd5d3..44b39f7031 100644
--- a/src/shared/constants/providers.ts
+++ b/src/shared/constants/providers.ts
@@ -1743,6 +1743,7 @@ export const USAGE_SUPPORTED_PROVIDERS = [
   "glmt",
   "minimax",
   "minimax-cn",
+  "crof",
 ];
 
 // ── Zod validation at module load (Phase 7.2) ──
diff --git a/src/sse/handlers/chat.ts b/src/sse/handlers/chat.ts
index 8079dac461..6151a60706 100644
--- a/src/sse/handlers/chat.ts
+++ b/src/sse/handlers/chat.ts
@@ -70,6 +70,7 @@ import {
   registerCodexQuotaFetcher,
 } from "@omniroute/open-sse/services/codexQuotaFetcher.ts";
 import { registerBailianCodingPlanQuotaFetcher } from "@omniroute/open-sse/services/bailianQuotaFetcher.ts";
+import { registerCrofUsageFetcher } from "@omniroute/open-sse/services/crofUsageFetcher.ts";
 import {
   getCooldownAwareRetryDecision,
   resolveCooldownAwareRetrySettings,
@@ -83,6 +84,11 @@ registerCodexQuotaFetcher();
 // can proactively switch accounts before quota is exhausted.
 registerBailianCodingPlanQuotaFetcher();
 
+// Register CrofAI usage fetcher (subscription requests + credits balance).
+// Surfaces usable_requests + credits in the monitor and only blocks (preflight
+// opt-in) when the active bucket reaches zero.
+registerCrofUsageFetcher();
+
 function normalizeAllowedConnectionIds(value: unknown): string[] | null {
   if (!Array.isArray(value)) return null;
   const ids = value.filter(
diff --git a/tests/unit/crof-usage-fetcher.test.ts b/tests/unit/crof-usage-fetcher.test.ts
new file mode 100644
index 0000000000..2cdcb0897d
--- /dev/null
+++ b/tests/unit/crof-usage-fetcher.test.ts
@@ -0,0 +1,101 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+const {
+  parseCrofUsageResponse,
+  fetchCrofUsage,
+  invalidateCrofUsageCache,
+  registerCrofUsageFetcher,
+} = await import("../../open-sse/services/crofUsageFetcher.ts");
+
+test("parseCrofUsageResponse: subscription account with remaining requests", () => {
+  const quota = parseCrofUsageResponse({ usable_requests: 450, credits: 12.34 });
+  assert.ok(quota);
+  assert.equal(quota.usableRequests, 450);
+  assert.equal(quota.credits, 12.34);
+  assert.equal(quota.percentUsed, 0, "non-zero requests must not block");
+  assert.equal(quota.total, 450);
+});
+
+test("parseCrofUsageResponse: subscription account exhausted blocks (percentUsed=1)", () => {
+  const quota = parseCrofUsageResponse({ usable_requests: 0, credits: 0 });
+  assert.ok(quota);
+  assert.equal(quota.usableRequests, 0);
+  assert.equal(quota.percentUsed, 1);
+});
+
+test("parseCrofUsageResponse: pay-as-you-go account uses credits as gate", () => {
+  const positive = parseCrofUsageResponse({ usable_requests: null, credits: 5.5 });
+  assert.ok(positive);
+  assert.equal(positive.usableRequests, null);
+  assert.equal(positive.credits, 5.5);
+  assert.equal(positive.percentUsed, 0);
+
+  const empty = parseCrofUsageResponse({ usable_requests: null, credits: 0 });
+  assert.ok(empty);
+  assert.equal(empty.percentUsed, 1);
+});
+
+test("parseCrofUsageResponse: handles string-encoded numbers (defensive)", () => {
+  const quota = parseCrofUsageResponse({ usable_requests: "200", credits: "3.75" });
+  assert.ok(quota);
+  assert.equal(quota.usableRequests, 200);
+  assert.equal(quota.credits, 3.75);
+  assert.equal(quota.percentUsed, 0);
+});
+
+test("parseCrofUsageResponse: rejects non-object payloads", () => {
+  assert.equal(parseCrofUsageResponse(null), null);
+  assert.equal(parseCrofUsageResponse("hello"), null);
+  assert.equal(parseCrofUsageResponse([]), null);
+});
+
+test("fetchCrofUsage: returns null when the connection has no apiKey (fail-open)", async () => {
+  const result = await fetchCrofUsage("conn-no-key", { apiKey: "" });
+  assert.equal(result, null);
+});
+
+test("fetchCrofUsage: caches the parsed response and serves it from memory", async () => {
+  const fakeKey = `unit-${Date.now()}`;
+  let calls = 0;
+  const originalFetch = globalThis.fetch;
+  globalThis.fetch = async () => {
+    calls += 1;
+    return new Response(JSON.stringify({ usable_requests: 99, credits: 1.5 }), {
+      status: 200,
+      headers: { "content-type": "application/json" },
+    });
+  };
+
+  try {
+    invalidateCrofUsageCache(fakeKey);
+    const first = await fetchCrofUsage(fakeKey, { apiKey: "test-key" });
+    const second = await fetchCrofUsage(fakeKey, { apiKey: "test-key" });
+    assert.ok(first && second);
+    assert.equal(first.percentUsed, 0);
+    assert.equal((first as { usableRequests?: number }).usableRequests, 99);
+    assert.equal(calls, 1, "second call must hit the cache, not the network");
+  } finally {
+    globalThis.fetch = originalFetch;
+    invalidateCrofUsageCache(fakeKey);
+  }
+});
+
+test("fetchCrofUsage: returns null on non-2xx and clears cache on auth failure", async () => {
+  const fakeKey = `unit-401-${Date.now()}`;
+  const originalFetch = globalThis.fetch;
+  globalThis.fetch = async () => new Response("nope", { status: 401 });
+  try {
+    invalidateCrofUsageCache(fakeKey);
+    const result = await fetchCrofUsage(fakeKey, { apiKey: "bad-key" });
+    assert.equal(result, null);
+  } finally {
+    globalThis.fetch = originalFetch;
+    invalidateCrofUsageCache(fakeKey);
+  }
+});
+
+test("registerCrofUsageFetcher: idempotent registration call does not throw", () => {
+  registerCrofUsageFetcher();
+  registerCrofUsageFetcher();
+});
diff --git a/tests/unit/crof-usage.test.ts b/tests/unit/crof-usage.test.ts
new file mode 100644
index 0000000000..b2bc747ff6
--- /dev/null
+++ b/tests/unit/crof-usage.test.ts
@@ -0,0 +1,114 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+const usage = await import("../../open-sse/services/usage.ts");
+const { USAGE_SUPPORTED_PROVIDERS } = await import("../../src/shared/constants/providers.ts");
+
+test("USAGE_SUPPORTED_PROVIDERS includes crof", () => {
+  assert.ok(
+    (USAGE_SUPPORTED_PROVIDERS as string[]).includes("crof"),
+    "crof must be in the usage-supported providers allowlist"
+  );
+});
+
+test("getUsageForProvider returns helpful message when crof has no apiKey", async () => {
+  const result = (await usage.getUsageForProvider({
+    id: "crof-no-key",
+    provider: "crof",
+    apiKey: "",
+  })) as { message?: string };
+  assert.ok(typeof result.message === "string");
+  assert.match(result.message!, /CrofAI/);
+});
+
+test("getUsageForProvider exposes Requests Today + Credits for subscription accounts", async () => {
+  const originalFetch = globalThis.fetch;
+  globalThis.fetch = async () =>
+    new Response(JSON.stringify({ usable_requests: 450, credits: 12.3456 }), {
+      status: 200,
+      headers: { "content-type": "application/json" },
+    });
+  try {
+    const result = (await usage.getUsageForProvider({
+      id: "crof-sub",
+      provider: "crof",
+      apiKey: "test-key",
+    })) as {
+      quotas?: Record<
+        string,
+        {
+          used: number;
+          total: number;
+          remaining: number;
+          displayName?: string;
+          unlimited: boolean;
+          resetAt?: string | null;
+        }
+      >;
+    };
+    assert.ok(result.quotas, "quotas must be returned");
+    assert.ok(result.quotas!["Requests Today"], "Requests Today quota must be present");
+    assert.equal(result.quotas!["Requests Today"].remaining, 450);
+    assert.match(result.quotas!["Requests Today"].displayName!, /450 left/);
+    // Total must default to the Pro-plan baseline (1000) so the dashboard's
+    // percentage formula reads "remaining/total" rather than 0% (red, depleted).
+    assert.equal(result.quotas!["Requests Today"].total, 1000);
+    assert.equal(result.quotas!["Requests Today"].used, 550);
+    // CrofAI does not return a reset timestamp; we synthesize next UTC midnight
+    // so the dashboard's countdown renders. Assert it parses to a future Date
+    // within the next 24h without pinning the exact boundary.
+    const resetAt = result.quotas!["Requests Today"].resetAt;
+    assert.equal(typeof resetAt, "string", "Requests Today.resetAt must be an ISO string");
+    const resetTs = Date.parse(resetAt!);
+    assert.ok(Number.isFinite(resetTs), "Requests Today.resetAt must parse");
+    const deltaMs = resetTs - Date.now();
+    assert.ok(deltaMs > 0, "Requests Today.resetAt must be in the future");
+    assert.ok(deltaMs <= 24 * 60 * 60 * 1000, "Requests Today.resetAt must be within 24h");
+    assert.ok(result.quotas!["Credits"], "Credits quota must be present");
+    assert.equal(result.quotas!["Credits"].unlimited, true);
+    assert.match(result.quotas!["Credits"].displayName!, /\$12\.3456/);
+    assert.equal(result.quotas!["Credits"].resetAt ?? null, null, "Credits has no reset bucket");
+  } finally {
+    globalThis.fetch = originalFetch;
+  }
+});
+
+test("getUsageForProvider omits Requests Today on pay-as-you-go (usable_requests=null)", async () => {
+  const originalFetch = globalThis.fetch;
+  globalThis.fetch = async () =>
+    new Response(JSON.stringify({ usable_requests: null, credits: 5.5 }), {
+      status: 200,
+      headers: { "content-type": "application/json" },
+    });
+  try {
+    const result = (await usage.getUsageForProvider({
+      id: "crof-payg",
+      provider: "crof",
+      apiKey: "test-key",
+    })) as { quotas?: Record<string, unknown> };
+    assert.ok(result.quotas);
+    assert.equal(
+      result.quotas!["Requests Today"],
+      undefined,
+      "no Requests Today quota when not on a subscription plan"
+    );
+    assert.ok(result.quotas!["Credits"]);
+  } finally {
+    globalThis.fetch = originalFetch;
+  }
+});
+
+test("getUsageForProvider returns 401 message when crof rejects the api key", async () => {
+  const originalFetch = globalThis.fetch;
+  globalThis.fetch = async () => new Response("nope", { status: 401 });
+  try {
+    const result = (await usage.getUsageForProvider({
+      id: "crof-401",
+      provider: "crof",
+      apiKey: "bad-key",
+    })) as { message?: string };
+    assert.match(result.message ?? "", /rejected/);
+  } finally {
+    globalThis.fetch = originalFetch;
+  }
+});