diff --git a/open-sse/services/usage.ts b/open-sse/services/usage.ts
index 698e65fd..0e2c5fc9 100644
--- a/open-sse/services/usage.ts
+++ b/open-sse/services/usage.ts
@@ -703,8 +703,10 @@ async function getAntigravityUsage(accessToken, providerSpecificData) {
         continue;
       }
 
-      const remainingFraction = toNumber(quotaInfo.remainingFraction, 0);
+      const rawFraction = toNumber(quotaInfo.remainingFraction, -1);
       const resetAt = parseResetTime(quotaInfo.resetTime);
+      // Default to 100% when the API doesn't report a fraction
+      const remainingFraction = rawFraction < 0 ? 1 : rawFraction;
       // Models with no resetTime and full remaining are unlimited (e.g. tab-completion models)
       const isUnlimited = !resetAt && remainingFraction >= 1;
       const remainingPercentage = remainingFraction * 100;