From d21f571e21cbba8a79d7a9efdaa89835e3856214 Mon Sep 17 00:00:00 2001
From: Stephen Schoettler <stephenschoettler@gmail.com>
Date: Thu, 26 Feb 2026 12:08:28 -0800
Subject: [PATCH] fix: add null guards to usage sort comparators

Prevents crash when totals is undefined in byModel/byProvider/byAgent
sort comparators. Fixes 'Cannot read properties of undefined (reading
totalTokens)' crash that causes context overflow in active sessions.
---
 src/gateway/server-methods/usage.ts | 10 +++++-----
 src/infra/session-cost-usage.ts     |  4 ++--
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/gateway/server-methods/usage.ts b/src/gateway/server-methods/usage.ts
index e40af58f5fe..3546c25723c 100644
--- a/src/gateway/server-methods/usage.ts
+++ b/src/gateway/server-methods/usage.ts
@@ -844,22 +844,22 @@ export const usageHandlers: GatewayRequestHandlers = {
           .toSorted((a, b) => b.count - a.count),
       },
       byModel: Array.from(byModelMap.values()).toSorted((a, b) => {
-        const costDiff = b.totals.totalCost - a.totals.totalCost;
+        const costDiff = (b.totals?.totalCost ?? 0) - (a.totals?.totalCost ?? 0);
         if (costDiff !== 0) {
           return costDiff;
         }
-        return b.totals.totalTokens - a.totals.totalTokens;
+        return (b.totals?.totalTokens ?? 0) - (a.totals?.totalTokens ?? 0);
       }),
       byProvider: Array.from(byProviderMap.values()).toSorted((a, b) => {
-        const costDiff = b.totals.totalCost - a.totals.totalCost;
+        const costDiff = (b.totals?.totalCost ?? 0) - (a.totals?.totalCost ?? 0);
         if (costDiff !== 0) {
           return costDiff;
         }
-        return b.totals.totalTokens - a.totals.totalTokens;
+        return (b.totals?.totalTokens ?? 0) - (a.totals?.totalTokens ?? 0);
       }),
       byAgent: Array.from(byAgentMap.entries())
         .map(([id, totals]) => ({ agentId: id, totals }))
-        .toSorted((a, b) => b.totals.totalCost - a.totals.totalCost),
+        .toSorted((a, b) => (b.totals?.totalCost ?? 0) - (a.totals?.totalCost ?? 0)),
       ...tail,
     };
 
diff --git a/src/infra/session-cost-usage.ts b/src/infra/session-cost-usage.ts
index 230ebd60c2e..4c021bcc72f 100644
--- a/src/infra/session-cost-usage.ts
+++ b/src/infra/session-cost-usage.ts
@@ -707,11 +707,11 @@ export async function loadSessionCostSummary(params: {
 
   const modelUsage = modelUsageMap.size
     ? Array.from(modelUsageMap.values()).toSorted((a, b) => {
-        const costDiff = b.totals.totalCost - a.totals.totalCost;
+        const costDiff = (b.totals?.totalCost ?? 0) - (a.totals?.totalCost ?? 0);
         if (costDiff !== 0) {
           return costDiff;
         }
-        return b.totals.totalTokens - a.totals.totalTokens;
+        return (b.totals?.totalTokens ?? 0) - (a.totals?.totalTokens ?? 0);
       })
     : undefined;