diff --git a/src/index.ts b/src/index.ts
index c9bf8d9..8c97a01 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -45,4 +45,15 @@ export class CognitoUtil {
     localStorage.setItem('idToken', idToken);
     localStorage.setItem('expiresAt', expiresAt.toString());
   }
+
+  public isAuthenticated(): boolean {
+    const expiresAt = window.localStorage.getItem('expiresAt');
+    return expiresAt != null && new Date().getTime() < Number(expiresAt);
+  }
+
+  public getIdToken(): string | null {
+    return this.isAuthenticated()
+      ? window.localStorage.getItem('idToken')
+      : null;
+  }
 }
diff --git a/tsconfig.json b/tsconfig.json
index 55d6644..3e19548 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -4,18 +4,18 @@
 
     /* Basic Options */
     // "incremental": true,                   /* Enable incremental compilation */
-    "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */
-    "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */
+    "target": "es5" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */,
+    "module": "commonjs" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */,
     // "lib": [],                             /* Specify library files to be included in the compilation. */
     // "allowJs": true,                       /* Allow javascript files to be compiled. */
     // "checkJs": true,                       /* Report errors in .js files. */
     // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
-    "declaration": true,                      /* Generates corresponding '.d.ts' file. */
+    "declaration": true /* Generates corresponding '.d.ts' file. */,
     // "declarationMap": true,                /* Generates a sourcemap for each corresponding '.d.ts' file. */
-    "sourceMap": true,                        /* Generates corresponding '.map' file. */
+    "sourceMap": true /* Generates corresponding '.map' file. */,
     // "outFile": "./",                       /* Concatenate and emit output to single file. */
-    "outDir": "./dist",                       /* Redirect output structure to the directory. */
-    "rootDir": "./src",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
+    "outDir": "./dist" /* Redirect output structure to the directory. */,
+    "rootDir": "./src" /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */,
     // "composite": true,                     /* Enable project compilation */
     // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
     // "removeComments": true,                /* Do not emit comments to output. */
@@ -25,7 +25,7 @@
     // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
 
     /* Strict Type-Checking Options */
-    "strict": true,                           /* Enable all strict type-checking options. */
+    "strict": true /* Enable all strict type-checking options. */,
     // "noImplicitAny": true,                 /* Raise error on expressions and declarations with an implied 'any' type. */
     // "strictNullChecks": true,              /* Enable strict null checks. */
     // "strictFunctionTypes": true,           /* Enable strict checking of function types. */
@@ -48,7 +48,7 @@
     // "typeRoots": [],                       /* List of folders to include type definitions from. */
     // "types": [],                           /* Type declaration files to be included in compilation. */
     // "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
-    "esModuleInterop": true,                  /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
+    "esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */,
     // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */
     // "allowUmdGlobalAccess": true,          /* Allow accessing UMD globals from modules. */
 
@@ -63,7 +63,7 @@
     // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
 
     /* Advanced Options */
-    "skipLibCheck": true,                     /* Skip type checking of declaration files. */
-    "forceConsistentCasingInFileNames": true  /* Disallow inconsistently-cased references to the same file. */
+    "skipLibCheck": true /* Skip type checking of declaration files. */,
+    "forceConsistentCasingInFileNames": true /* Disallow inconsistently-cased references to the same file. */
   }
 }