diff --git a/backend/internal/service/antigravity_gateway_service.go b/backend/internal/service/antigravity_gateway_service.go
index 4922de3c..fa5b477b 100644
--- a/backend/internal/service/antigravity_gateway_service.go
+++ b/backend/internal/service/antigravity_gateway_service.go
@@ -1619,6 +1619,9 @@ func (s *AntigravityGatewayService) Forward(ctx context.Context, c *gin.Context,
 		firstTokenMs = streamRes.firstTokenMs
 	}
 
+	// Claude Max cache billing: 同步 ForwardResult.Usage 与客户端响应体一致
+	applyClaudeMaxCacheBillingPolicyToUsage(usage, parsedRequestFromGinContext(c), claudeMaxGroupFromGinContext(c), originalModel, account.ID)
+
 	return &ForwardResult{
 		RequestID:        requestID,
 		Usage:            *usage,
diff --git a/backend/internal/service/gateway_record_usage_claude_max_test.go b/backend/internal/service/gateway_record_usage_claude_max_test.go
index 2e1b5ae7..3cd86938 100644
--- a/backend/internal/service/gateway_record_usage_claude_max_test.go
+++ b/backend/internal/service/gateway_record_usage_claude_max_test.go
@@ -92,10 +92,10 @@ func TestRecordUsage_SimulateClaudeMaxEnabled_ProjectsUsageAndSkipsTTLOverride(t
 	require.NotNil(t, repo.last)
 
 	log := repo.last
-	require.Equal(t, 160, log.InputTokens)
-	require.Equal(t, 0, log.CacheCreationTokens)
+	require.Equal(t, 80, log.InputTokens)
+	require.Equal(t, 80, log.CacheCreationTokens)
 	require.Equal(t, 0, log.CacheCreation5mTokens)
-	require.Equal(t, 0, log.CacheCreation1hTokens)
+	require.Equal(t, 80, log.CacheCreation1hTokens)
 	require.False(t, log.CacheTTLOverridden, "simulate outcome should skip account ttl override")
 }
 
@@ -195,5 +195,5 @@ func TestRecordUsage_SimulateClaudeMaxEnabled_ExistingCacheCreationBypassesSimul
 	require.Equal(t, 120, log.CacheCreation5mTokens)
 	require.Equal(t, 0, log.CacheCreation1hTokens)
 	require.Equal(t, 120, log.CacheCreationTokens)
-	require.True(t, log.CacheTTLOverridden, "existing cache_creation with SimulateClaudeMax enabled should apply account ttl override")
+	require.False(t, log.CacheTTLOverridden, "existing cache_creation with SimulateClaudeMax enabled should skip account ttl override")
 }
diff --git a/backend/internal/service/gateway_service.go b/backend/internal/service/gateway_service.go
index 2b47509e..af34d472 100644
--- a/backend/internal/service/gateway_service.go
+++ b/backend/internal/service/gateway_service.go
@@ -5630,8 +5630,9 @@ func (s *GatewayService) RecordUsage(ctx context.Context, input *RecordUsageInpu
 	if apiKey != nil {
 		apiKeyGroup = apiKey.Group
 	}
-	claudeMaxOutcome := detectClaudeMaxCacheBillingOutcomeForUsage(result.Usage, input.ParsedRequest, apiKeyGroup, result.Model)
-	simulatedClaudeMax := claudeMaxOutcome.Simulated
+	claudeMaxOutcome := applyClaudeMaxCacheBillingPolicyToUsage(&result.Usage, input.ParsedRequest, apiKeyGroup, result.Model, account.ID)
+	simulatedClaudeMax := claudeMaxOutcome.Simulated ||
+		(shouldApplyClaudeMaxBillingRulesForUsage(apiKeyGroup, result.Model, input.ParsedRequest) && hasCacheCreationTokens(result.Usage))
 	// Cache TTL Override: 确保计费时 token 分类与账号设置一致
 	cacheTTLOverridden := false
 	if account.IsCacheTTLOverrideEnabled() && !simulatedClaudeMax {