diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 00000000..4d8aa0f2
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,3 @@
+## 2025-02-28 - Batch concurrent fs operations to avoid EMFILE limits
+**Learning:** When iterating over a large number of files in `ArtifactStore.gc`, sequential `fs.stat` and `fs.rm` checks create performance bottlenecks and sequential loops. Although fully parallelizing could cause EMFILE errors, batched concurrent execution solves both performance and limit issues.
+**Action:** Use chunked batched `Promise.all` requests with a chunk size of 10 for mass `fs.stat` and `fs.rm` operations.
diff --git a/src/core/sub-agent/artifacts/store.ts b/src/core/sub-agent/artifacts/store.ts
index 8a7aff5c..7720eee4 100644
--- a/src/core/sub-agent/artifacts/store.ts
+++ b/src/core/sub-agent/artifacts/store.ts
@@ -93,13 +93,26 @@ export class ArtifactStore {
     const entries = await fs.readdir(root, { withFileTypes: true }).catch(() => []);
 
     const files: Array<{ name: string; path: string; mtimeMs: number; size: number }> = [];
-    for (const entry of entries) {
-      if (!entry.isFile()) continue;
-      const filePath = path.join(root, entry.name);
-      if (!isWithinDir(root, filePath)) continue;
-      const stat = await fs.stat(filePath).catch(() => null);
-      if (!stat) continue;
-      files.push({ name: entry.name, path: filePath, mtimeMs: stat.mtimeMs, size: stat.size });
+    const validEntries = entries.filter((e) => {
+      if (!e.isFile()) return false;
+      const filePath = path.join(root, e.name);
+      return isWithinDir(root, filePath);
+    });
+
+    for (let i = 0; i < validEntries.length; i += 10) {
+      const chunk = validEntries.slice(i, i + 10);
+      const stats = await Promise.all(
+        chunk.map(async (entry) => {
+          const filePath = path.join(root, entry.name);
+          const stat = await fs.stat(filePath).catch(() => null);
+          return { entry, filePath, stat };
+        }),
+      );
+      for (const { entry, filePath, stat } of stats) {
+        if (stat) {
+          files.push({ name: entry.name, path: filePath, mtimeMs: stat.mtimeMs, size: stat.size });
+        }
+      }
     }
 
     const maxAgeMs = options?.maxAgeMs ?? LIMITS.artifactTtlMs;
@@ -118,8 +131,9 @@ export class ArtifactStore {
       removedBytes += file.size;
     };
 
-    for (const file of expired) {
-      await removeFile(file);
+    for (let i = 0; i < expired.length; i += 10) {
+      const chunk = expired.slice(i, i + 10);
+      await Promise.all(chunk.map((file) => removeFile(file)));
     }
 
     // Recompute remaining after TTL removal (newest first).
diff --git a/tests/integration/prompt_templates.test.ts b/tests/integration/prompt_templates.test.ts
index 21905259..f1360d78 100644
--- a/tests/integration/prompt_templates.test.ts
+++ b/tests/integration/prompt_templates.test.ts
@@ -36,7 +36,9 @@ describe('Prompt templates', () => {
 
     expect(planSystem).toContain('You are SalmonLoop.');
     expect(patchSystem).toContain('You are PATCH, a phase-native diff compiler.');
-    expect(autopilotSystem).toContain('You are a senior software engineer running in "autopilot" mode.');
+    expect(autopilotSystem).toContain(
+      'You are a senior software engineer running in "autopilot" mode.',
+    );
     expect(answerSystem).toContain('You are a coding assistant in "answer" mode.');
     expect(researchSystem).toContain('You are a research assistant.');
   });