diff --git a/src/main/rate-limits/antigravity-usage-mirror.test.ts b/src/main/rate-limits/antigravity-usage-mirror.test.ts
new file mode 100644
index 000000000000..84c92e1ad22f
--- /dev/null
+++ b/src/main/rate-limits/antigravity-usage-mirror.test.ts
@@ -0,0 +1,70 @@
+import { describe, expect, it } from 'vitest'
+import type { ProviderRateLimits, ProviderRateLimitStatus } from '../../shared/rate-limit-types'
+import { deriveAntigravityRateLimits } from './antigravity-usage-mirror'
+
+function geminiSnapshot(
+  status: ProviderRateLimitStatus,
+  error: string | null,
+  usedPercent: number | null = null
+): ProviderRateLimits {
+  return {
+    provider: 'gemini',
+    session:
+      usedPercent === null
+        ? null
+        : { usedPercent, windowMinutes: 300, resetsAt: null, resetDescription: null },
+    weekly: null,
+    updatedAt: 1_700_000_000_000,
+    error,
+    status
+  }
+}
+
+describe('deriveAntigravityRateLimits', () => {
+  it('mirrors a successful Gemini read as shared Code Assist quota', () => {
+    const antigravity = deriveAntigravityRateLimits(geminiSnapshot('ok', null, 42))
+
+    expect(antigravity.provider).toBe('antigravity')
+    expect(antigravity.status).toBe('ok')
+    expect(antigravity.session?.usedPercent).toBe(42)
+    expect(antigravity.error).toBeNull()
+  })
+
+  it('reports unavailable without quoting the Gemini failure', () => {
+    const antigravity = deriveAntigravityRateLimits(
+      geminiSnapshot('error', 'Gemini project ID not found')
+    )
+
+    expect(antigravity.provider).toBe('antigravity')
+    expect(antigravity.status).toBe('unavailable')
+    expect(antigravity.error).not.toContain('Gemini project ID not found')
+    expect(antigravity.error).toContain('Antigravity usage is not available')
+    expect(antigravity.session).toBeNull()
+    expect(antigravity.weekly).toBeNull()
+  })
+
+  it('does not blame a missing sign-in when the quota read itself failed', () => {
+    const antigravity = deriveAntigravityRateLimits(geminiSnapshot('error', 'Token refresh failed'))
+
+    // Why: the reported symptom is a connected sign-in whose Code Assist read failed.
+    expect(antigravity.error).toContain('could not be read right now')
+    expect(antigravity.error).not.toContain('sign-in is connected')
+  })
+
+  it('keeps the Gemini timestamp so activation freshness checks are not forced to refetch', () => {
+    const antigravity = deriveAntigravityRateLimits(geminiSnapshot('error', 'Token refresh failed'))
+
+    expect(antigravity.updatedAt).toBe(1_700_000_000_000)
+  })
+
+  it('points at the missing sign-in when the Gemini opt-in is off', () => {
+    const antigravity = deriveAntigravityRateLimits(
+      geminiSnapshot('unavailable', 'Gemini CLI OAuth is disabled in settings')
+    )
+
+    expect(antigravity.status).toBe('unavailable')
+    expect(antigravity.error).not.toContain('Gemini CLI OAuth is disabled in settings')
+    expect(antigravity.error).toContain('Antigravity usage is not available')
+    expect(antigravity.error).toContain('Gemini CLI sign-in is connected')
+  })
+})
diff --git a/src/main/rate-limits/antigravity-usage-mirror.ts b/src/main/rate-limits/antigravity-usage-mirror.ts
new file mode 100644
index 000000000000..3cea6decc111
--- /dev/null
+++ b/src/main/rate-limits/antigravity-usage-mirror.ts
@@ -0,0 +1,29 @@
+import type { ProviderRateLimits } from '../../shared/rate-limit-types'
+
+// Why: the Antigravity CLI keeps its token in the OS keyring, not in the files the Gemini
+// fetcher reads, so Orca never actually queries Antigravity. Only a *successful* Gemini read
+// describes shared Google Code Assist quota; republishing a Gemini failure under the
+// Antigravity provider id surfaced "Refresh failed" for a request that was never attempted.
+const ANTIGRAVITY_NO_SIGN_IN_REASON =
+  'Antigravity usage is not available. Orca can only show shared Google Code Assist quota while a Gemini CLI sign-in is connected.'
+// Why: a Gemini `error` means the sign-in exists and the quota read failed, so blaming a missing sign-in would misdirect the user.
+const ANTIGRAVITY_QUOTA_UNREADABLE_REASON =
+  'Antigravity usage is not available. Orca reads it from the shared Google Code Assist quota, which could not be read right now.'
+
+export function deriveAntigravityRateLimits(gemini: ProviderRateLimits): ProviderRateLimits {
+  if (gemini.status === 'ok') {
+    return { ...gemini, provider: 'antigravity' }
+  }
+  return {
+    provider: 'antigravity',
+    session: null,
+    weekly: null,
+    // Why: reuse the Gemini timestamp so activation freshness checks don't force a refetch every cycle.
+    updatedAt: gemini.updatedAt,
+    error:
+      gemini.status === 'unavailable'
+        ? ANTIGRAVITY_NO_SIGN_IN_REASON
+        : ANTIGRAVITY_QUOTA_UNREADABLE_REASON,
+    status: 'unavailable'
+  }
+}
diff --git a/src/main/rate-limits/service-antigravity-usage.test.ts b/src/main/rate-limits/service-antigravity-usage.test.ts
new file mode 100644
index 000000000000..b617d9099443
--- /dev/null
+++ b/src/main/rate-limits/service-antigravity-usage.test.ts
@@ -0,0 +1,100 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { RateLimitService } from './service'
+import { fetchClaudeRateLimits } from './claude-fetcher'
+import { fetchCodexRateLimits } from './codex-fetcher'
+import { fetchGeminiRateLimits } from './gemini-usage-fetcher'
+import {
+  errorProvider,
+  okProvider,
+  resetRateLimitProviderMocks
+} from './rate-limit-service-test-harness'
+
+vi.mock('./claude-fetcher', () => ({
+  fetchClaudeRateLimits: vi.fn(),
+  fetchManagedAccountUsage: vi.fn()
+}))
+
+vi.mock('./codex-fetcher', () => ({
+  consumeCodexRateLimitResetCredit: vi.fn(),
+  fetchCodexRateLimits: vi.fn()
+}))
+
+vi.mock('./gemini-usage-fetcher', () => ({
+  fetchGeminiRateLimits: vi.fn()
+}))
+
+vi.mock('./kimi-fetcher', () => ({
+  fetchKimiRateLimits: vi.fn()
+}))
+
+vi.mock('./opencode-go-usage-fetcher', () => ({
+  fetchOpenCodeGoRateLimits: vi.fn()
+}))
+
+vi.mock('./minimax-fetcher', () => ({
+  fetchMiniMaxRateLimits: vi.fn()
+}))
+
+vi.mock('./grok-fetcher', () => ({
+  fetchGrokRateLimits: vi.fn()
+}))
+
+vi.mock('./grok-auth', () => ({
+  readGrokAuthSession: vi.fn(() => ({ status: 'missing' }))
+}))
+
+vi.mock('../minimax/minimax-cookie-store', () => ({
+  hasMiniMaxSessionCookie: vi.fn(() => false)
+}))
+
+describe('RateLimitService Antigravity usage', () => {
+  beforeEach(() => {
+    resetRateLimitProviderMocks()
+    vi.mocked(fetchClaudeRateLimits).mockResolvedValue(okProvider('claude', 7))
+    vi.mocked(fetchCodexRateLimits).mockResolvedValue(okProvider('codex', 20))
+  })
+
+  it('does not republish a Gemini failure as an Antigravity refresh failure', async () => {
+    vi.mocked(fetchGeminiRateLimits).mockResolvedValue(
+      errorProvider('gemini', 'Gemini project ID not found')
+    )
+    const service = new RateLimitService()
+
+    await service.refresh()
+
+    const state = service.getState()
+    expect(state.antigravity?.status).toBe('unavailable')
+    expect(state.antigravity?.error).not.toContain('Gemini project ID not found')
+    expect(state.antigravity?.session).toBeNull()
+    // Why: the real Gemini failure must still surface under its own provider.
+    expect(state.gemini?.status).toBe('error')
+    expect(state.gemini?.error).toBe('Gemini project ID not found')
+  })
+
+  it('keeps mirroring a successful Gemini read under the Antigravity provider', async () => {
+    vi.mocked(fetchGeminiRateLimits).mockResolvedValue(okProvider('gemini', 42, Date.now()))
+    const service = new RateLimitService()
+
+    await service.refresh()
+
+    const state = service.getState()
+    expect(state.antigravity?.status).toBe('ok')
+    expect(state.antigravity?.provider).toBe('antigravity')
+    expect(state.antigravity?.session?.usedPercent).toBe(42)
+  })
+
+  it('never leaves a cached Antigravity snapshot in the error retry lane', async () => {
+    vi.mocked(fetchGeminiRateLimits).mockResolvedValueOnce(okProvider('gemini', 42, Date.now()))
+    const service = new RateLimitService()
+    await service.refresh()
+
+    vi.mocked(fetchGeminiRateLimits).mockResolvedValue(
+      errorProvider('gemini', 'Token refresh failed')
+    )
+    await service.refresh()
+
+    // Why: stale-retention would otherwise show Gemini numbers as "Refresh failed" Antigravity usage.
+    expect(service.getState().antigravity?.status).toBe('unavailable')
+    expect(service.getState().antigravity?.session).toBeNull()
+  })
+})
diff --git a/src/main/rate-limits/service.ts b/src/main/rate-limits/service.ts
index 02bd1930bb6b..d6f291d6b38e 100644
--- a/src/main/rate-limits/service.ts
+++ b/src/main/rate-limits/service.ts
@@ -20,6 +20,7 @@ import {
   type NormalizedClaudeAccountSelectionTarget
 } from '../claude-accounts/runtime-selection'
 import { fetchGeminiRateLimits } from './gemini-usage-fetcher'
+import { deriveAntigravityRateLimits } from './antigravity-usage-mirror'
 import { fetchKimiRateLimits } from './kimi-fetcher'
 import type { KimiHomeResolution } from '../kimi/kimi-runtime-home'
 import { fetchGrokRateLimits } from './grok-fetcher'
@@ -1766,11 +1767,8 @@ export class RateLimitService {
             status: 'error'
           } satisfies ProviderRateLimits)
 
-    // Why: Antigravity shares Gemini credentials today; mirror the Gemini snapshot so its status-bar UI gets a real lifecycle instead of null.
-    const antigravity: ProviderRateLimits = {
-      ...gemini,
-      provider: 'antigravity'
-    }
+    // Why: Antigravity can only borrow a *successful* Gemini read; a Gemini failure is not an Antigravity failure.
+    const antigravity = deriveAntigravityRateLimits(gemini)
 
     const opencodeGo =
       opencodeGoResult.status === 'fulfilled'