diff --git a/packages/server/src/server/agent/providers/codex-rollout-timeline.ts b/packages/server/src/server/agent/providers/codex-rollout-timeline.ts
index f30bd342b..bcd825d98 100644
--- a/packages/server/src/server/agent/providers/codex-rollout-timeline.ts
+++ b/packages/server/src/server/agent/providers/codex-rollout-timeline.ts
@@ -20,28 +20,40 @@ function resolveCodexSessionRoot(): string | null {
 }
 
 async function findRolloutFile(threadId: string, root: string): Promise<string | null> {
-  const stack: { dir: string; depth: number }[] = [{ dir: root, depth: 0 }];
-  while (stack.length > 0) {
-    const { dir, depth } = stack.pop()!;
-    let entries: Dirent[];
-    try {
-      entries = await fs.readdir(dir, { withFileTypes: true });
-    } catch {
-      continue;
-    }
-    for (const entry of entries) {
-      const entryPath = path.join(dir, entry.name);
-      if (entry.isFile()) {
-        const matchesThread = entry.name.includes(threadId);
-        const matchesPrefix = entry.name.startsWith("rollout-");
-        const matchesExtension = entry.name.endsWith(".json") || entry.name.endsWith(".jsonl");
-        if (matchesThread && matchesPrefix && matchesExtension) {
-          return entryPath;
+  let currentLevel: { dir: string; depth: number }[] = [{ dir: root, depth: 0 }];
+  while (currentLevel.length > 0) {
+    const readings = await Promise.all(
+      currentLevel.map(async ({ dir, depth }) => {
+        let entries: Dirent[];
+        try {
+          entries = await fs.readdir(dir, { withFileTypes: true });
+        } catch {
+          return { match: null as string | null, next: [] as { dir: string; depth: number }[] };
         }
-      } else if (entry.isDirectory() && depth < MAX_ROLLOUT_SEARCH_DEPTH) {
-        stack.push({ dir: entryPath, depth: depth + 1 });
-      }
+        let match: string | null = null;
+        const next: { dir: string; depth: number }[] = [];
+        for (const entry of entries) {
+          const entryPath = path.join(dir, entry.name);
+          if (entry.isFile()) {
+            const matchesThread = entry.name.includes(threadId);
+            const matchesPrefix = entry.name.startsWith("rollout-");
+            const matchesExtension =
+              entry.name.endsWith(".json") || entry.name.endsWith(".jsonl");
+            if (matchesThread && matchesPrefix && matchesExtension && match === null) {
+              match = entryPath;
+            }
+          } else if (entry.isDirectory() && depth < MAX_ROLLOUT_SEARCH_DEPTH) {
+            next.push({ dir: entryPath, depth: depth + 1 });
+          }
+        }
+        return { match, next };
+      }),
+    );
+    const firstMatch = readings.find((reading) => reading.match !== null);
+    if (firstMatch?.match) {
+      return firstMatch.match;
     }
+    currentLevel = readings.flatMap((reading) => reading.next);
   }
   return null;
 }