diff --git a/eslint.config.js b/eslint.config.js
new file mode 100644
index 0000000..7a4def3
--- /dev/null
+++ b/eslint.config.js
@@ -0,0 +1,32 @@
+const tsPlugin = require('@typescript-eslint/eslint-plugin');
+const tsParser = require('@typescript-eslint/parser');
+
+module.exports = [
+  {
+    ignores: ['build/', 'dist/', 'node_modules/', 'logs/', 'coverage/'],
+  },
+  {
+    files: ['src/**/*.ts'],
+    languageOptions: {
+      parser: tsParser,
+      parserOptions: {
+        ecmaVersion: 2022,
+        sourceType: 'module',
+      },
+      globals: {
+        console: 'readonly',
+        process: 'readonly',
+        Buffer: 'readonly',
+        __dirname: 'readonly',
+        __filename: 'readonly',
+      },
+    },
+    plugins: {
+      '@typescript-eslint': tsPlugin,
+    },
+    rules: {
+      '@typescript-eslint/no-explicit-any': 'off',
+      '@typescript-eslint/no-unused-vars': ['warn', { argsIgnorePattern: '^_' }],
+    },
+  },
+];
diff --git a/package.json b/package.json
index 5a0e6bd..5c8ca7a 100644
--- a/package.json
+++ b/package.json
@@ -9,8 +9,8 @@
     "train:audio": "tsc && node build/Agent/training/TrainWithAudio.js",
     "train:youtube": "tsc && node build/Agent/training/youtubeURL.js",
     "test": "jest",
-    "lint": "eslint src --ext .ts",
-    "lint:fix": "eslint src --ext .ts --fix",
+    "lint": "eslint src",
+    "lint:fix": "eslint src --fix",
     "format": "prettier --write .",
     "format:check": "prettier --check .",
     "typecheck": "tsc -p tsconfig.json --noEmit",
diff --git a/src/utils/index.test.ts b/src/utils/index.test.ts
index cbb88db..4110a21 100644
--- a/src/utils/index.test.ts
+++ b/src/utils/index.test.ts
@@ -4,6 +4,7 @@ import {
   Instagram_cookiesExist,
   getIgDailyState,
   incrementIgDailyCount,
+  isCookieValid,
   loadCookies,
 } from './index';
 
@@ -68,6 +69,46 @@ describe('utils', () => {
     expect(backup).toBeTruthy();
   });
 
+  test('Instagram_cookiesExist accepts session cookies with expires -1', async () => {
+    await fs.mkdir(cookiesDir, { recursive: true });
+    await fs.writeFile(
+      cookiesPath,
+      JSON.stringify([{ name: 'sessionid', value: 'abc', expires: -1 }]),
+      'utf-8',
+    );
+
+    expect(await Instagram_cookiesExist()).toBe(true);
+  });
+
+  test('Instagram_cookiesExist rejects expired timed cookies', async () => {
+    await fs.mkdir(cookiesDir, { recursive: true });
+    const past = Math.floor(Date.now() / 1000) - 3600;
+    await fs.writeFile(
+      cookiesPath,
+      JSON.stringify([{ name: 'sessionid', value: 'abc', expires: past }]),
+      'utf-8',
+    );
+
+    expect(await Instagram_cookiesExist()).toBe(false);
+  });
+
+  test('Instagram_cookiesExist accepts future timed cookies', async () => {
+    await fs.mkdir(cookiesDir, { recursive: true });
+    const future = Math.floor(Date.now() / 1000) + 3600;
+    await fs.writeFile(
+      cookiesPath,
+      JSON.stringify([{ name: 'sessionid', value: 'abc', expires: future }]),
+      'utf-8',
+    );
+
+    expect(await Instagram_cookiesExist()).toBe(true);
+  });
+
+  test('isCookieValid treats Puppeteer session cookies as valid', () => {
+    const now = Math.floor(Date.now() / 1000);
+    expect(isCookieValid({ name: 'sessionid', expires: -1 }, now)).toBe(true);
+  });
+
   test('loadCookies returns [] for invalid JSON and backs up file', async () => {
     await fs.mkdir(cookiesDir, { recursive: true });
     await fs.writeFile(cookiesPath, '{"bad_json":', 'utf-8');
diff --git a/src/utils/index.ts b/src/utils/index.ts
index f032a0e..94eed65 100644
--- a/src/utils/index.ts
+++ b/src/utils/index.ts
@@ -27,6 +27,17 @@ async function withFileLock<T>(filePath: string, fn: () => Promise<T>): Promise<
   }
 }
 
+type CookieLike = { name: string; expires?: number };
+
+/** Puppeteer session cookies use expires -1; timed cookies use a Unix timestamp. */
+export const isCookieValid = (cookie: CookieLike | undefined, nowSec: number): boolean => {
+  if (!cookie) return false;
+  const { expires } = cookie;
+  if (expires === -1 || expires === undefined) return true;
+  if (typeof expires !== 'number') return false;
+  return expires > nowSec;
+};
+
 /** Cookie file path for a given account key (legacy default path kept for "default"). */
 export function getInstagramCookiesPath(accountKey: string = 'default'): string {
   const key = accountKey || 'default';
@@ -36,12 +47,6 @@ export function getInstagramCookiesPath(accountKey: string = 'default'): string
   return `./cookies/Instagramcookies-${key}.json`;
 }
 
-const isCookieValid = (cookie: { expires?: number } | undefined, now: number): boolean => {
-  if (!cookie) return false;
-  if (cookie.expires === undefined || cookie.expires === -1) return true;
-  return cookie.expires > now;
-};
-
 /**
  * Checks if valid Instagram cookies exist and are not expired
  * @returns True if valid cookies exist, false otherwise