diff --git a/components/Layout.tsx b/components/Layout.tsx
new file mode 100644
index 0000000..2bd6e5d
--- /dev/null
+++ b/components/Layout.tsx
@@ -0,0 +1,76 @@
+import Link from 'next/link'
+import React, { ReactNode } from 'react'
+import A from '../ui/A'
+import { useAuth } from '../hooks/useAuth'
+
+type Props = {
+  children: ReactNode
+}
+
+const Layout = ({ children }: Props) => {
+  const { user } = useAuth()
+
+  return (
+    <div className="flex flex-col min-h-screen">
+      <header className="p-4 shadow">
+        <div className="flex items-center justify-between">
+          <Link href="/" passHref>
+            <A href="#!">
+              <img src="logo.png" alt="Cremona" className="h-12" />
+            </A>
+          </Link>
+          <div className="flex">{user ? <LoggedOut /> : <LoggedIn />}</div>
+        </div>
+      </header>
+      <main className="flex-1 p-4">{children}</main>
+      <footer className="p-4">
+        <p className="text-center">
+          <span>Created by </span>
+          <Link href="/signin" passHref>
+            <A
+              href="http://twitter.com/durancristhian"
+              target="_blank"
+              rel="noopener noreferrer"
+            >
+              @durancristhian
+            </A>
+          </Link>
+        </p>
+      </footer>
+    </div>
+  )
+}
+
+export default Layout
+
+function LoggedIn() {
+  return (
+    <>
+      <Link href="/signin" passHref>
+        <A href="#!">Sign in</A>
+      </Link>
+      <div className="ml-4">
+        <Link href="/signup" passHref>
+          <A href="#!">Sign up</A>
+        </Link>
+      </div>
+    </>
+  )
+}
+
+function LoggedOut() {
+  const { signout } = useAuth()
+
+  return (
+    <>
+      <button
+        onClick={() => {
+          signout()
+        }}
+        className="text-blue-700"
+      >
+        Sing out
+      </button>
+    </>
+  )
+}
diff --git a/components/Login.tsx b/components/Login.tsx
new file mode 100644
index 0000000..c5e24a9
--- /dev/null
+++ b/components/Login.tsx
@@ -0,0 +1,105 @@
+import { useRouter } from 'next/router'
+import React, { FormEvent, useState } from 'react'
+import { useAuth } from '../hooks/useAuth'
+
+type LoginMode = 'signin' | 'signup'
+
+type Props = {
+  mode: LoginMode
+}
+
+const Login = ({ mode }: Props) => {
+  const router = useRouter()
+  const [formData, setFormData] = useState({
+    email: '',
+    password: '',
+  })
+  const [inProgress, setInProgress] = useState(false)
+  const [message, setMessage] = useState('')
+  const { signin, signup } = useAuth()
+
+  const onSubmit = (event: FormEvent) => {
+    event.preventDefault()
+
+    setInProgress(true)
+    setMessage('Processing...')
+
+    const method = mode === 'signin' ? signin : signup
+
+    method(formData.email, formData.password)
+      .then(() => {
+        setInProgress(false)
+        setMessage('')
+
+        router.push('/')
+      })
+      .catch((error: Error) => {
+        console.error(error)
+
+        setInProgress(false)
+        setMessage(error.message)
+      })
+  }
+
+  return (
+    <>
+      <div className="mb-4">
+        <h1>{mode === 'signin' ? 'Sign In' : 'Sign Up'}</h1>
+      </div>
+      <form onSubmit={onSubmit}>
+        <fieldset disabled={inProgress}>
+          <div className="mb-4">
+            <input
+              type="email"
+              name="email"
+              id="email"
+              value={formData.email}
+              onChange={({ target }) => {
+                setFormData({
+                  ...formData,
+                  email: target.value,
+                })
+              }}
+              placeholder="Email"
+              autoComplete="email"
+              className="block px-4 py-2 shadow w-full"
+            />
+          </div>
+          <div className="mb-4">
+            <input
+              type="password"
+              name="password"
+              id="password"
+              value={formData.password}
+              onChange={({ target }) => {
+                setFormData({
+                  ...formData,
+                  password: target.value,
+                })
+              }}
+              placeholder="Password"
+              autoComplete="current-password"
+              className="block px-4 py-2 shadow w-full"
+            />
+          </div>
+          <div className="text-center">
+            <button
+              type="submit"
+              className="border bg-blue-200 border-blue-500 px-4 py-2 disabled:opacity-50"
+              disabled={!formData.email || !formData.password}
+            >
+              {mode === 'signin' ? 'Sign In' : 'Sign Up'}
+            </button>
+          </div>
+          {message && (
+            <div className="mt-4 text-center">
+              <p className="italic">{message}</p>
+            </div>
+          )}
+        </fieldset>
+      </form>
+    </>
+  )
+}
+
+export default Login
diff --git a/hooks/useAuth.tsx b/hooks/useAuth.tsx
new file mode 100644
index 0000000..21e8dc3
--- /dev/null
+++ b/hooks/useAuth.tsx
@@ -0,0 +1,86 @@
+import { fuego } from '@nandorojo/swr-firestore'
+import React, {
+  createContext,
+  ReactNode,
+  useContext,
+  useEffect,
+  useState,
+} from 'react'
+
+type ContextData = {
+  user: firebase.User | null
+  signin: (email: string, password: string) => Promise<firebase.User | null>
+  signup: (email: string, password: string) => Promise<firebase.User | null>
+  signout: () => Promise<void>
+}
+
+const defaultContextData = {
+  user: null,
+  signin: () => Promise.resolve(null),
+  signup: () => Promise.resolve(null),
+  signout: () => Promise.resolve(void 0),
+}
+
+const AuthContext = createContext<ContextData>(defaultContextData)
+
+type Props = {
+  children: ReactNode
+}
+
+export function ProvideAuth({ children }: Props) {
+  const auth = useProvideAuth()
+
+  return <AuthContext.Provider value={auth}>{children}</AuthContext.Provider>
+}
+
+export const useAuth = () => {
+  return useContext(AuthContext)
+}
+
+function useProvideAuth() {
+  const [user, setUser] = useState<firebase.User | null>(null)
+
+  const signin = (email: string, password: string) => {
+    return fuego
+      .auth()
+      .signInWithEmailAndPassword(email, password)
+      .then((response) => {
+        setUser(response.user)
+        return response.user
+      })
+  }
+
+  const signup = (email: string, password: string) => {
+    return fuego
+      .auth()
+      .createUserWithEmailAndPassword(email, password)
+      .then((response) => {
+        setUser(response.user)
+        return response.user
+      })
+  }
+
+  const signout = () => {
+    return fuego
+      .auth()
+      .signOut()
+      .then(() => {
+        setUser(null)
+      })
+  }
+
+  useEffect(() => {
+    const unsubscribe = fuego.auth().onAuthStateChanged((user) => {
+      setUser(user)
+    })
+
+    return () => unsubscribe()
+  }, [])
+
+  return {
+    user,
+    signin,
+    signup,
+    signout,
+  }
+}
diff --git a/pages/_app.tsx b/pages/_app.tsx
index 73fce5d..1117b29 100644
--- a/pages/_app.tsx
+++ b/pages/_app.tsx
@@ -1,9 +1,35 @@
+import { Fuego, FuegoProvider } from '@nandorojo/swr-firestore'
+import 'firebase/auth'
+import 'firebase/firestore'
 import { AppProps } from 'next/app'
 import React from 'react'
+import Layout from '../components/Layout'
+import { ProvideAuth } from '../hooks/useAuth'
 import '../styles/globals.css'
 
+const firebaseConfig = {
+  apiKey: process.env.NEXT_PUBLIC_API_KEY,
+  authDomain: process.env.NEXT_PUBLIC_AUTH_DOMAIN,
+  databaseURL: process.env.NEXT_PUBLIC_DATABASE_URL,
+  projectId: process.env.NEXT_PUBLIC_PROJECT_ID,
+  storageBucket: process.env.NEXT_PUBLIC_STORAGE_BUCKET,
+  messagingSenderId: process.env.NEXT_PUBLIC_MESSAGING_SENDER_ID,
+  appId: process.env.NEXT_PUBLIC_APP_ID,
+  measurementId: process.env.NEXT_PUBLIC_MEASUREMENT_ID,
+}
+
+const fuego = new Fuego(firebaseConfig)
+
 const App = ({ Component, pageProps }: AppProps) => {
-  return <Component {...pageProps} />
+  return (
+    <FuegoProvider fuego={fuego}>
+      <ProvideAuth>
+        <Layout>
+          <Component {...pageProps} />
+        </Layout>
+      </ProvideAuth>
+    </FuegoProvider>
+  )
 }
 
 export default App
diff --git a/pages/_document.tsx b/pages/_document.tsx
index e7535c5..496e2b5 100644
--- a/pages/_document.tsx
+++ b/pages/_document.tsx
@@ -8,7 +8,7 @@ class MyDocument extends Document {
         <Head>
           <link rel="shortcut icon" href="favicon.ico" type="image/x-icon" />
         </Head>
-        <body className="debug">
+        <body className="bg-orange-100">
           <Main />
           <NextScript />
         </body>
diff --git a/pages/index.tsx b/pages/index.tsx
index 97e513d..b6c2cc0 100644
--- a/pages/index.tsx
+++ b/pages/index.tsx
@@ -1,10 +1,8 @@
 import React from 'react'
+import { useAuth } from '../hooks/useAuth'
 
 export default function Index() {
-  return (
-    <>
-      <img src="logo.png" alt="Cremona" />
-      <h1>Cremona</h1>
-    </>
-  )
+  const { user } = useAuth()
+
+  return <div className="p-4">{user ? 'Hello' : null}</div>
 }
diff --git a/pages/signin.tsx b/pages/signin.tsx
new file mode 100644
index 0000000..357aae8
--- /dev/null
+++ b/pages/signin.tsx
@@ -0,0 +1,12 @@
+import React from 'react'
+import Login from '../components/Login'
+
+const SignIn = () => {
+  return (
+    <>
+      <Login mode="signin"></Login>
+    </>
+  )
+}
+
+export default SignIn
diff --git a/pages/signup.tsx b/pages/signup.tsx
new file mode 100644
index 0000000..99d3175
--- /dev/null
+++ b/pages/signup.tsx
@@ -0,0 +1,12 @@
+import React from 'react'
+import Login from '../components/Login'
+
+const SignUp = () => {
+  return (
+    <>
+      <Login mode="signup"></Login>
+    </>
+  )
+}
+
+export default SignUp
diff --git a/ui/A.tsx b/ui/A.tsx
new file mode 100644
index 0000000..c4944bb
--- /dev/null
+++ b/ui/A.tsx
@@ -0,0 +1,19 @@
+import React, { AnchorHTMLAttributes, forwardRef, ReactNode, Ref } from 'react'
+
+type Props = AnchorHTMLAttributes<HTMLAnchorElement> & {
+  children: ReactNode
+}
+
+const A = forwardRef(
+  ({ children, ...rest }: Props, ref: Ref<HTMLAnchorElement>) => {
+    return (
+      <a ref={ref} {...rest} className="text-blue-700">
+        {children}
+      </a>
+    )
+  },
+)
+
+A.displayName = 'A'
+
+export default A