diff --git a/src/features/app/hooks/useAppServerEvents.ts b/src/features/app/hooks/useAppServerEvents.ts
index 45dd3dffb..137f5f49b 100644
--- a/src/features/app/hooks/useAppServerEvents.ts
+++ b/src/features/app/hooks/useAppServerEvents.ts
@@ -77,7 +77,7 @@ type AppServerEventHandlers = {
   onThreadTokenUsageUpdated?: (
     workspaceId: string,
     threadId: string,
-    tokenUsage: Record<string, unknown>,
+    tokenUsage: Record<string, unknown> | null,
   ) => void;
   onAccountRateLimitsUpdated?: (
     workspaceId: string,
@@ -299,9 +299,9 @@ export function useAppServerEvents(handlers: AppServerEventHandlers) {
       if (method === "thread/tokenUsage/updated") {
         const threadId = String(params.threadId ?? params.thread_id ?? "");
         const tokenUsage =
-          (params.tokenUsage as Record<string, unknown> | undefined) ??
-          (params.token_usage as Record<string, unknown> | undefined);
-        if (threadId && tokenUsage) {
+          (params.tokenUsage as Record<string, unknown> | null | undefined) ??
+          (params.token_usage as Record<string, unknown> | null | undefined);
+        if (threadId && tokenUsage !== undefined) {
           handlers.onThreadTokenUsageUpdated?.(workspace_id, threadId, tokenUsage);
         }
         return;
diff --git a/src/features/threads/hooks/useThreadTurnEvents.ts b/src/features/threads/hooks/useThreadTurnEvents.ts
index 4f1913bc9..dac3dbda5 100644
--- a/src/features/threads/hooks/useThreadTurnEvents.ts
+++ b/src/features/threads/hooks/useThreadTurnEvents.ts
@@ -171,7 +171,11 @@ export function useThreadTurnEvents({
   );
 
   const onThreadTokenUsageUpdated = useCallback(
-    (workspaceId: string, threadId: string, tokenUsage: Record<string, unknown>) => {
+    (
+      workspaceId: string,
+      threadId: string,
+      tokenUsage: Record<string, unknown> | null,
+    ) => {
       dispatch({ type: "ensureThread", workspaceId, threadId });
       dispatch({
         type: "setThreadTokenUsage",
diff --git a/src/features/threads/utils/threadNormalize.ts b/src/features/threads/utils/threadNormalize.ts
index dbcc0625c..4a62be296 100644
--- a/src/features/threads/utils/threadNormalize.ts
+++ b/src/features/threads/utils/threadNormalize.ts
@@ -73,9 +73,12 @@ export function extractReviewThreadId(response: unknown): string | null {
   return threadId || null;
 }
 
-export function normalizeTokenUsage(raw: Record<string, unknown>): ThreadTokenUsage {
-  const total = (raw.total as Record<string, unknown>) ?? {};
-  const last = (raw.last as Record<string, unknown>) ?? {};
+export function normalizeTokenUsage(
+  raw: Record<string, unknown> | null | undefined,
+): ThreadTokenUsage {
+  const source = raw ?? {};
+  const total = (source.total as Record<string, unknown>) ?? {};
+  const last = (source.last as Record<string, unknown>) ?? {};
   return {
     total: {
       totalTokens: asNumber(total.totalTokens ?? total.total_tokens),
@@ -98,7 +101,7 @@ export function normalizeTokenUsage(raw: Record<string, unknown>): ThreadTokenUs
       ),
     },
     modelContextWindow: (() => {
-      const value = raw.modelContextWindow ?? raw.model_context_window;
+      const value = source.modelContextWindow ?? source.model_context_window;
       if (typeof value === "number") {
         return value;
       }