diff --git a/frontend/src/utils/__tests__/ccswitchImport.spec.ts b/frontend/src/utils/__tests__/ccswitchImport.spec.ts
index 6f23c1aa3b..fd178f76fd 100644
--- a/frontend/src/utils/__tests__/ccswitchImport.spec.ts
+++ b/frontend/src/utils/__tests__/ccswitchImport.spec.ts
@@ -1,5 +1,6 @@
 import { describe, expect, it } from 'vitest'
 import {
+  CC_SWITCH_USAGE_SCRIPT,
   GROK_CC_SWITCH_MODEL,
   OPENAI_CC_SWITCH_CODEX_MODEL,
   buildCcSwitchImportDeeplink
@@ -100,3 +101,38 @@ describe('ccswitchImport utils', () => {
     expect(params.has('model')).toBe(false)
   })
 })
+
+describe('CC Switch usage script', () => {
+  // Mirrors CC Switch: substitute the template vars as text, evaluate, read request.url.
+  function usageUrlFor(baseUrl: string): string {
+    const script = CC_SWITCH_USAGE_SCRIPT.split('{{baseUrl}}').join(baseUrl).split('{{apiKey}}').join('sk-test')
+    // eslint-disable-next-line no-new-func
+    const config = new Function(`return ${script}`)() as { request: { url: string } }
+    return config.request.url
+  }
+
+  it.each([
+    'https://api.example.com',
+    'https://api.example.com/',
+    'https://api.example.com/v1',
+    'https://api.example.com/v1/'
+  ])('queries exactly one /v1/usage for base URL %s', (baseUrl) => {
+    expect(usageUrlFor(baseUrl)).toBe('https://api.example.com/v1/usage')
+  })
+
+  it('works against the endpoint every platform import stores', () => {
+    for (const platform of ['anthropic', 'openai', 'grok', 'gemini'] as GroupPlatform[]) {
+      const endpoint = paramsFromDeeplink(
+        buildCcSwitchImportDeeplink({
+          baseUrl: 'https://api.example.com',
+          platform,
+          clientType: platform === 'gemini' ? 'gemini' : 'claude',
+          providerName: 'Sub2API',
+          apiKey: 'sk-test',
+          usageScript: CC_SWITCH_USAGE_SCRIPT
+        })
+      ).get('endpoint') as string
+      expect(usageUrlFor(endpoint)).toBe('https://api.example.com/v1/usage')
+    }
+  })
+})
diff --git a/frontend/src/utils/ccswitchImport.ts b/frontend/src/utils/ccswitchImport.ts
index f9ca257349..1aee39d159 100644
--- a/frontend/src/utils/ccswitchImport.ts
+++ b/frontend/src/utils/ccswitchImport.ts
@@ -20,6 +20,31 @@ export interface CcSwitchImportDeeplinkInput {
   usageScript: string
 }
 
+/**
+ * Balance query CC Switch runs against the imported provider. CC Switch fills
+ * `{{baseUrl}}` with the provider's base URL as stored — Codex and Grok imports
+ * carry a trailing `/v1` (see `withV1Endpoint`), Claude ones do not, and users
+ * may edit it either way afterwards — then evaluates the script, so the URL
+ * strips an existing `/v1` instead of blindly appending one (`/v1/v1/usage`
+ * is a 404 and CC Switch shows "query failed").
+ */
+export const CC_SWITCH_USAGE_SCRIPT = `({
+    request: {
+      url: "{{baseUrl}}".replace(/\\/+$/, "").replace(/\\/v1$/, "") + "/v1/usage",
+      method: "GET",
+      headers: { "Authorization": "Bearer {{apiKey}}" }
+    },
+    extractor: function(response) {
+      const remaining = response?.remaining ?? response?.quota?.remaining ?? response?.balance;
+      const unit = response?.unit ?? response?.quota?.unit ?? "USD";
+      return {
+        isValid: response?.is_active ?? response?.isValid ?? true,
+        remaining,
+        unit
+      };
+    }
+  })`
+
 function withV1Endpoint(baseUrl: string): string {
   const normalizedBaseUrl = baseUrl.replace(/\/+$/, '')
   return normalizedBaseUrl.endsWith('/v1') ? normalizedBaseUrl : `${normalizedBaseUrl}/v1`
diff --git a/frontend/src/views/user/KeysView.vue b/frontend/src/views/user/KeysView.vue
index ed33a4c683..3011b52a11 100644
--- a/frontend/src/views/user/KeysView.vue
+++ b/frontend/src/views/user/KeysView.vue
@@ -1231,6 +1231,7 @@ import PlatformIcon from '@/components/common/PlatformIcon.vue'
 import { platformBadgeLightClass } from '@/utils/platformColors'
 import { KEY_GROUP_PROVIDERS, KEY_GROUP_PROVIDER_ICONS, getKeyGroupProvider, type KeyGroupProvider } from '@/utils/keyGroupProviders'
 import {
+  CC_SWITCH_USAGE_SCRIPT,
   buildCcSwitchImportDeeplink,
   type CcSwitchClientType
 } from '@/utils/ccswitchImport'
@@ -2025,22 +2026,7 @@ const executeCcsImport = (row: ApiKey, clientType: CcSwitchClientType) => {
   const baseUrl = publicSettings.value?.api_base_url || window.location.origin
   const platform = row.group?.platform || 'anthropic'
 
-  const usageScript = `({
-    request: {
-      url: "{{baseUrl}}/v1/usage",
-      method: "GET",
-      headers: { "Authorization": "Bearer {{apiKey}}" }
-    },
-    extractor: function(response) {
-      const remaining = response?.remaining ?? response?.quota?.remaining ?? response?.balance;
-      const unit = response?.unit ?? response?.quota?.unit ?? "USD";
-      return {
-        isValid: response?.is_active ?? response?.isValid ?? true,
-        remaining,
-        unit
-      };
-    }
-  })`
+  const usageScript = CC_SWITCH_USAGE_SCRIPT
   const providerName = (publicSettings.value?.site_name || 'sub2api').trim() || 'sub2api'
   const deeplink = buildCcSwitchImportDeeplink({
     baseUrl,