diff --git a/src/api/common/firebase.ts b/src/api/common/firebase.ts
index 197ea058..46963120 100644
--- a/src/api/common/firebase.ts
+++ b/src/api/common/firebase.ts
@@ -1,5 +1,10 @@
 import { Env } from '@env';
 import { initializeApp } from 'firebase/app';
+import {
+  connectAuthEmulator,
+  getReactNativePersistence,
+  initializeAuth,
+} from 'firebase/auth';
 import {
   connectFirestoreEmulator,
   initializeFirestore,
@@ -7,6 +12,7 @@ import {
 import { connectFunctionsEmulator, getFunctions } from 'firebase/functions';
 import { Platform } from 'react-native';
 
+import { reactNativeAsyncStorage } from '../../core/storage';
 const firebaseConfig = {
   apiKey: Env.EXPO_PUBLIC_FIREBASE_API_KEY,
   authDomain: Env.EXPO_PUBLIC_FIREBASE_AUTH_DOMAIN,
@@ -21,12 +27,20 @@ export const app = initializeApp(firebaseConfig);
 export const db = initializeFirestore(app, {
   experimentalForceLongPolling: true,
 });
-const functions = getFunctions(app);
+export const functions = getFunctions(app);
+export const auth = initializeAuth(app, {
+  persistence: getReactNativePersistence(reactNativeAsyncStorage),
+});
 
 // Connect to emulator
 // 10.0.2.2 is a special IP address to connect to the 'localhost' of the host computer from an Android emulator
 const emulatorHost = Platform.OS === 'ios' ? '127.0.0.1' : '10.0.2.2';
+const FIRESTORE_PORT = 8080;
+const FUNCTIONS_PORT = 5001;
+const AUTH_PORT = 9099;
+
 if (__DEV__) {
-  connectFirestoreEmulator(db, emulatorHost, 8080);
-  connectFunctionsEmulator(functions, emulatorHost, 5001);
+  connectFirestoreEmulator(db, emulatorHost, FIRESTORE_PORT);
+  connectFunctionsEmulator(functions, emulatorHost, FUNCTIONS_PORT);
+  connectAuthEmulator(auth, `http://${emulatorHost}:${AUTH_PORT}`);
 }
diff --git a/src/app/(tabs)/settings.tsx b/src/app/(tabs)/settings.tsx
index c2a4fd80..5a8a61c2 100644
--- a/src/app/(tabs)/settings.tsx
+++ b/src/app/(tabs)/settings.tsx
@@ -1,17 +1,27 @@
 /* eslint-disable react/react-in-jsx-scope */
 import { Env } from '@env';
+import { useState } from 'react';
 import { Linking } from 'react-native';
 
 import { Item } from '@/components/settings/item';
 import { ItemsContainer } from '@/components/settings/items-container';
 import { ThemeItem } from '@/components/settings/theme-item';
 import { useAuth } from '@/core';
-import { Header, ScreenContainer, ScrollView, View } from '@/ui';
+import { Button, Header, ScreenContainer, ScrollView, View } from '@/ui';
 
 export default function Settings() {
   const signOut = useAuth.use.signOut();
-  // const { colorScheme } = useColorScheme();
-  // const iconColor = colorScheme === 'dark' ? colors.neutral[400] : colors.neutral[500];
+  const [isLoading, setIsLoading] = useState(false);
+  const handleLogout = async () => {
+    setIsLoading(true);
+    try {
+      await signOut();
+    } catch (error) {
+      console.error('Logout error:', error);
+    } finally {
+      setIsLoading(false);
+    }
+  };
   return (
     <ScreenContainer>
       <Header title="Settings" />
@@ -83,9 +93,12 @@ export default function Settings() {
           </ItemsContainer>
 
           <View className="my-8">
-            <ItemsContainer>
-              <Item text="Logout" onPress={signOut} />
-            </ItemsContainer>
+            <Button
+              label="Logout"
+              onPress={handleLogout}
+              loading={isLoading}
+              variant="item"
+            />
           </View>
         </View>
       </ScrollView>
diff --git a/src/app/auth/index.tsx b/src/app/auth/index.tsx
index bfb6923a..b4b4099d 100644
--- a/src/app/auth/index.tsx
+++ b/src/app/auth/index.tsx
@@ -1,14 +1,20 @@
 import { zodResolver } from '@hookform/resolvers/zod';
 import { useRouter } from 'expo-router';
+import { httpsCallable } from 'firebase/functions';
 import { useColorScheme } from 'nativewind';
-import React from 'react';
+import { useState } from 'react';
 import { useForm } from 'react-hook-form';
 import { KeyboardAvoidingView } from 'react-native-keyboard-controller';
 import * as z from 'zod';
 
+import { functions } from '@/api/common/firebase';
 import Logo from '@/components/logo';
 import { Button, ControlledInput, ScreenContainer, Text, View } from '@/ui';
 
+const userExistsSchema = z.object({
+  exists: z.boolean(),
+});
+
 const emailSchema = z.object({
   email: z
     .string({
@@ -21,10 +27,11 @@ type EmailFormType = z.infer<typeof emailSchema>;
 
 export default function Auth() {
   const router = useRouter();
+  const [isLoading, setIsLoading] = useState(false);
   const { handleSubmit, control } = useForm<EmailFormType>({
     resolver: zodResolver(emailSchema),
     defaultValues: {
-      email: 'test@gmail.com',
+      email: 'blaze@mail.com',
     },
   });
 
@@ -33,19 +40,30 @@ export default function Auth() {
   const appleIconBlack = require('/assets/apple-icon-black.png');
 
   // eslint-disable-next-line unused-imports/no-unused-vars
-  const checkUserExists = async (email: string) => {
-    return true; // Change as needed
+  const checkUserExists = async (email: string): Promise<boolean> => {
+    try {
+      const checkUser = httpsCallable(functions, 'checkUserExistsInAuth');
+      const response = await checkUser({ email });
+      const data = userExistsSchema.parse(response.data);
+      return data.exists;
+    } catch (error) {
+      console.error('Error checking user existence:', error);
+      return false;
+    }
   };
 
   const onSubmit = async (data: EmailFormType) => {
-    const userExists = await checkUserExists(data.email);
-    if (userExists) {
+    setIsLoading(true);
+    try {
+      const userExists = await checkUserExists(data.email);
       router.push({
-        pathname: '/auth/login',
+        pathname: userExists ? '/auth/login' : '/auth/sign-up',
         params: { email: data.email },
       });
-    } else {
-      router.push({ pathname: '/auth/sign-up', params: { email: data.email } });
+    } catch (error) {
+      console.error(error);
+    } finally {
+      setIsLoading(false);
     }
   };
 
@@ -71,6 +89,7 @@ export default function Auth() {
           />
           <Button
             label="Continue With Email"
+            loading={isLoading}
             onPress={handleSubmit(onSubmit)}
           />
           <View className="flex-row items-center gap-3">
diff --git a/src/app/auth/login.tsx b/src/app/auth/login.tsx
index dd66c227..f695625f 100644
--- a/src/app/auth/login.tsx
+++ b/src/app/auth/login.tsx
@@ -1,6 +1,6 @@
 import { zodResolver } from '@hookform/resolvers/zod';
 import { useLocalSearchParams, useRouter } from 'expo-router';
-import React from 'react';
+import { useState } from 'react';
 import type { SubmitHandler } from 'react-hook-form';
 import { useForm } from 'react-hook-form';
 import { KeyboardAvoidingView } from 'react-native-keyboard-controller';
@@ -31,21 +31,27 @@ export default function Login() {
   const { email } = useLocalSearchParams<{ email: string }>();
   const router = useRouter();
   const signIn = useAuth.use.signIn();
+  const [isLoading, setIsLoading] = useState(false);
 
-  const { handleSubmit, control } = useForm<PasswordFormType>({
+  const { handleSubmit, control, setError } = useForm<PasswordFormType>({
     resolver: zodResolver(passwordSchema),
     defaultValues: {
       email,
-      password: '123456',
+      password: '',
     },
   });
-
-  const onSubmit: SubmitHandler<PasswordFormType> = (data) => {
-    console.log(data);
-    signIn({ access: 'access-token', refresh: 'refresh-token' });
-    router.push('/');
+  const onSubmit: SubmitHandler<PasswordFormType> = async (data) => {
+    setIsLoading(true);
+    try {
+      await signIn(data.email, data.password);
+      router.push('/');
+    } catch (error: any) {
+      console.error('Login Error:', error);
+      setError('password', { message: 'Invalid email or password' });
+    } finally {
+      setIsLoading(false);
+    }
   };
-
   return (
     <ScreenContainer>
       <KeyboardAvoidingView
@@ -73,7 +79,11 @@ export default function Login() {
           >
             Forgot Password?
           </Text>
-          <Button label="Login" onPress={handleSubmit(onSubmit)} />
+          <Button
+            label="Login"
+            loading={isLoading}
+            onPress={handleSubmit(onSubmit)}
+          />
         </View>
       </KeyboardAvoidingView>
     </ScreenContainer>
diff --git a/src/components/settings/item.tsx b/src/components/settings/item.tsx
index fcaccf4d..2c84f427 100644
--- a/src/components/settings/item.tsx
+++ b/src/components/settings/item.tsx
@@ -1,29 +1,48 @@
 import * as React from 'react';
+import { ActivityIndicator } from 'react-native';
 
 import { Pressable, Text, View } from '@/ui';
 
 type ItemProps = {
   text: string;
+  loading?: boolean;
   value?: string;
   onPress?: () => void;
   icon?: React.ReactNode;
 };
 
-export const Item = ({ text, value, icon, onPress }: ItemProps) => {
+export const Item = ({
+  text,
+  loading = false,
+  value,
+  icon,
+  onPress,
+}: ItemProps) => {
   const isPressable = onPress !== undefined;
+
   return (
     <Pressable
+      disabled={loading} // Disable button while loading
       onPress={onPress}
       pointerEvents={isPressable ? 'auto' : 'none'}
       className="flex-1 flex-row items-center justify-between px-4 py-2"
     >
       <View className="flex-row items-center">
         {icon && <View className="pr-2">{icon}</View>}
-        <Text>{text}</Text>
+        {loading ? (
+          <ActivityIndicator size="small" color="gray" />
+        ) : (
+          <Text>{text}</Text>
+        )}
       </View>
+
       <View className="flex-row items-center">
-        <Text className="text-neutral-600 dark:text-white">{value}</Text>
-        {isPressable && <View className="pl-2">{/* <ArrowRight /> */}</View>}
+        {!loading && (
+          <Text className="text-neutral-600 dark:text-white">{value}</Text>
+        )}
+        {isPressable && !loading && (
+          <View className="pl-2">{/* <ArrowRight /> */}</View>
+        )}
       </View>
     </Pressable>
   );
diff --git a/src/core/auth/index.tsx b/src/core/auth/index.tsx
index 0e0d426d..2a873dfd 100644
--- a/src/core/auth/index.tsx
+++ b/src/core/auth/index.tsx
@@ -1,45 +1,67 @@
+import {
+  onAuthStateChanged,
+  signInWithEmailAndPassword,
+  signOut as firebaseSignOut,
+  type User,
+} from 'firebase/auth';
 import { create } from 'zustand';
 
+import { auth } from '../../api/common/firebase'; // Ensure this imports your Firebase instance
 import { createSelectors } from '../utils';
-import type { TokenType } from './utils';
-import { getToken, removeToken, setToken } from './utils';
 
 interface AuthState {
-  token: TokenType | null;
+  user: User | null;
   status: 'idle' | 'signOut' | 'signIn';
-  signIn: (data: TokenType) => void;
-  signOut: () => void;
+  signIn: (email: string, password: string) => Promise<void>;
+  signOut: () => Promise<void>;
   hydrate: () => void;
 }
 
-const _useAuth = create<AuthState>((set, get) => ({
+const _useAuth = create<AuthState>((set) => ({
+  user: null,
   status: 'idle',
-  token: null,
-  signIn: (token) => {
-    setToken(token);
-    set({ status: 'signIn', token });
+
+  signIn: async (email, password) => {
+    try {
+      const userCredential = await signInWithEmailAndPassword(
+        auth,
+        email,
+        password,
+      );
+      set({ user: userCredential.user, status: 'signIn' });
+    } catch (error) {
+      console.error('SignIn Error:', error);
+      throw error;
+    }
   },
-  signOut: () => {
-    removeToken();
-    set({ status: 'signOut', token: null });
+
+  signOut: async () => {
+    try {
+      await firebaseSignOut(auth);
+      set({ user: null, status: 'signOut' });
+    } catch (error) {
+      console.error('SignOut Error:', error);
+    }
   },
+
   hydrate: () => {
-    try {
-      const userToken = getToken();
-      if (userToken !== null) {
-        get().signIn(userToken);
+    set({ status: 'idle' });
+
+    // Subscribe to Firebase auth state changes
+    onAuthStateChanged(auth, (user) => {
+      if (user) {
+        set({ user, status: 'signIn' });
       } else {
-        get().signOut();
+        set({ user: null, status: 'signOut' });
       }
-    } catch (e) {
-      // catch error here
-      // Maybe sign_out user!
-    }
+    });
   },
 }));
 
 export const useAuth = createSelectors(_useAuth);
 
+// Functions for easier usage in components
 export const signOut = () => _useAuth.getState().signOut();
-export const signIn = (token: TokenType) => _useAuth.getState().signIn(token);
+export const signIn = (email: string, password: string) =>
+  _useAuth.getState().signIn(email, password);
 export const hydrateAuth = () => _useAuth.getState().hydrate();
diff --git a/src/core/storage.tsx b/src/core/storage.tsx
index f7018093..ab93319b 100644
--- a/src/core/storage.tsx
+++ b/src/core/storage.tsx
@@ -2,6 +2,21 @@ import { MMKV } from 'react-native-mmkv';
 
 export const storage = new MMKV();
 
+export const reactNativeAsyncStorage = {
+  setItem: (key: string, value: string): Promise<void> => {
+    storage.set(key, value);
+    return Promise.resolve();
+  },
+  getItem: (key: string): Promise<string | null> => {
+    const value = storage.getString(key);
+    return Promise.resolve(value ?? null);
+  },
+  removeItem: (key: string): Promise<void> => {
+    storage.delete(key);
+    return Promise.resolve();
+  },
+};
+
 export function getItem<T>(key: string): T {
   const value = storage.getString(key);
   return value ? JSON.parse(value) || null : null;
diff --git a/src/ui/button.tsx b/src/ui/button.tsx
index 8c1efaf7..8d872f9e 100644
--- a/src/ui/button.tsx
+++ b/src/ui/button.tsx
@@ -48,6 +48,12 @@ const button = tv({
         label: 'text-black',
         indicator: 'text-black',
       },
+      item: {
+        container:
+          'rounded-md border border-neutral-200 dark:border-neutral-700 dark:bg-neutral-800',
+        label: 'text-black dark:text-neutral-100',
+        indicator: 'text-black dark:text-neutral-100',
+      },
     },
     size: {
       default: {
diff --git a/tsconfig.json b/tsconfig.json
index ff341b3a..36adad50 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -9,6 +9,9 @@
       ],
       "@env": [
         "./src/core/env.js"
+      ],
+      "@firebase/auth": [
+        "./node_modules/@firebase/auth/dist/index.rn.d.ts"
       ]
     },
     "esModuleInterop": true,