diff --git a/src/data-state-files.test.ts b/src/data-state-files.test.ts
new file mode 100644
index 0000000..d40d1c7
--- /dev/null
+++ b/src/data-state-files.test.ts
@@ -0,0 +1,43 @@
+import fs from 'fs';
+import os from 'os';
+import path from 'path';
+
+import { afterEach, describe, expect, it } from 'vitest';
+
+import { listUnexpectedDataStateFiles } from './data-state-files.js';
+
+const tempDirs: string[] = [];
+
+function makeTempDir(): string {
+  const tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'ejclaw-data-state-'));
+  tempDirs.push(tempDir);
+  return tempDir;
+}
+
+afterEach(() => {
+  for (const tempDir of tempDirs.splice(0)) {
+    fs.rmSync(tempDir, { force: true, recursive: true });
+  }
+});
+
+describe('listUnexpectedDataStateFiles', () => {
+  it('allows known runtime state files', () => {
+    const dataDir = makeTempDir();
+    fs.writeFileSync(path.join(dataDir, 'token-rotation-state.json'), '{}');
+    fs.writeFileSync(path.join(dataDir, 'codex-rotation-state.json'), '{}');
+    fs.writeFileSync(path.join(dataDir, 'codex-warmup-state.json'), '{}');
+    fs.writeFileSync(path.join(dataDir, 'claude-usage-cache.json'), '{}');
+    fs.writeFileSync(path.join(dataDir, 'restart-context.abc.json'), '{}');
+
+    expect(listUnexpectedDataStateFiles(dataDir)).toEqual([]);
+  });
+
+  it('reports unsupported legacy state files', () => {
+    const dataDir = makeTempDir();
+    fs.writeFileSync(path.join(dataDir, 'router_state.json'), '{}');
+
+    expect(listUnexpectedDataStateFiles(dataDir)).toEqual([
+      'router_state.json',
+    ]);
+  });
+});
diff --git a/src/data-state-files.ts b/src/data-state-files.ts
index 420e416..db6cff1 100644
--- a/src/data-state-files.ts
+++ b/src/data-state-files.ts
@@ -4,6 +4,7 @@ import path from 'path';
 const ALLOWED_DATA_JSON_PATTERNS = [
   /^token-rotation-state\.json$/,
   /^codex-rotation-state\.json$/,
+  /^codex-warmup-state\.json$/,
   /^claude-usage-cache\.json$/,
   /^restart-context\..+\.json$/,
 ];