diff --git a/src/main/rate-limits/grok-fetcher.test.ts b/src/main/rate-limits/grok-fetcher.test.ts
index b077b880576..a88112c49e3 100644
--- a/src/main/rate-limits/grok-fetcher.test.ts
+++ b/src/main/rate-limits/grok-fetcher.test.ts
@@ -100,6 +100,31 @@ describe('fetchGrokRateLimits', () => {
     )
   })
 
+  it('maps an omitted protobuf percentage as zero for a weekly credits period', async () => {
+    authState.file = freshAuthJson()
+    netFetchMock.mockResolvedValueOnce(
+      jsonResponse({
+        config: {
+          currentPeriod: {
+            type: 'USAGE_PERIOD_TYPE_WEEKLY',
+            start: '2026-07-17T19:38:56.948570+00:00',
+            end: '2026-07-24T19:38:56.948570+00:00'
+          },
+          billingPeriodStart: '2026-07-17T19:38:56.948570+00:00',
+          billingPeriodEnd: '2026-07-24T19:38:56.948570+00:00',
+          isUnifiedBillingUser: true
+        }
+      })
+    )
+
+    const result = await fetchGrokRateLimits()
+    expect(result.status).toBe('ok')
+    expect(result.weekly?.usedPercent).toBe(0)
+    expect(result.weekly?.resetsAt).toBe(Date.parse('2026-07-24T19:38:56.948570+00:00'))
+    expect(result.monthly).toBeUndefined()
+    expect(netFetchMock).toHaveBeenCalledTimes(1)
+  })
+
   it('returns unavailable when not signed in even if a token-less auth file exists', async () => {
     authState.file = JSON.stringify({})
     const result = await fetchGrokRateLimits()
@@ -119,17 +144,12 @@ describe('fetchGrokRateLimits', () => {
     expect(result.monthly).toBeUndefined()
   })
 
-  it('maps monthly included usage for unified-billing accounts without weekly credits', async () => {
+  it('maps monthly included usage for unified-billing accounts without a weekly period', async () => {
     authState.file = freshAuthJson()
     netFetchMock
       .mockResolvedValueOnce(
         jsonResponse({
           config: {
-            currentPeriod: {
-              type: 'USAGE_PERIOD_TYPE_WEEKLY',
-              start: '2026-07-10T19:38:56.948570+00:00',
-              end: '2026-07-17T19:38:56.948570+00:00'
-            },
             isUnifiedBillingUser: true,
             subscriptionTier: 'SuperGrok'
           }
diff --git a/src/main/rate-limits/grok-fetcher.ts b/src/main/rate-limits/grok-fetcher.ts
index 1e6d20f5cce..7a514010dbe 100644
--- a/src/main/rate-limits/grok-fetcher.ts
+++ b/src/main/rate-limits/grok-fetcher.ts
@@ -82,7 +82,11 @@ function parseResetDescription(isoString: string | undefined): string | null {
 }
 
 function mapWeeklyCredits(config: GrokBillingConfig): RateLimitWindow | null {
-  const usedPercent = config.creditUsagePercent
+  // Why: Grok's protobuf JSON omits zero-valued percentages; a declared weekly
+  // period without this field is 0% usage, not an absent weekly allowance.
+  const usedPercent =
+    config.creditUsagePercent ??
+    (config.currentPeriod?.type === 'USAGE_PERIOD_TYPE_WEEKLY' ? 0 : null)
   if (typeof usedPercent !== 'number' || !Number.isFinite(usedPercent)) {
     return null
   }