diff --git a/app/src/main/java/com/firebase/uidemo/ChooserActivity.java b/app/src/main/java/com/firebase/uidemo/ChooserActivity.java
index 612fe4ab9..158a2ebe7 100644
--- a/app/src/main/java/com/firebase/uidemo/ChooserActivity.java
+++ b/app/src/main/java/com/firebase/uidemo/ChooserActivity.java
@@ -26,6 +26,8 @@
 import android.view.ViewGroup;
 import android.widget.TextView;
 
+import com.firebase.ui.auth.AuthUI;
+import com.firebase.ui.auth.util.ExtraConstants;
 import com.firebase.uidemo.auth.AnonymousUpgradeActivity;
 import com.firebase.uidemo.auth.AuthUiActivity;
 import com.firebase.uidemo.database.firestore.FirestoreChatActivity;
@@ -43,6 +45,16 @@ public class ChooserActivity extends AppCompatActivity {
     @Override
     protected void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+
+        if (AuthUI.canHandleIntent(getIntent())) {
+            Intent intent = new Intent(ChooserActivity.this, AuthUiActivity
+                    .class);
+            intent.putExtra(ExtraConstants.EMAIL_LINK_SIGN_IN, getIntent().getData().toString());
+            startActivity(intent);
+            finish();
+            return;
+        }
+
         setContentView(R.layout.activity_chooser);
         ButterKnife.bind(this);
 
@@ -51,7 +63,8 @@ protected void onCreate(@Nullable Bundle savedInstanceState) {
         mActivities.setHasFixedSize(true);
     }
 
-    private static class ActivityChooserAdapter extends RecyclerView.Adapter<ActivityStarterHolder> {
+    private static class ActivityChooserAdapter
+            extends RecyclerView.Adapter<ActivityStarterHolder> {
         private static final Class[] CLASSES = new Class[]{
                 AuthUiActivity.class,
                 AnonymousUpgradeActivity.class,
@@ -97,7 +110,8 @@ public int getItemCount() {
         }
     }
 
-    private static class ActivityStarterHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
+    private static class ActivityStarterHolder extends RecyclerView.ViewHolder
+            implements View.OnClickListener {
         private TextView mTitle;
         private TextView mDescription;
 
diff --git a/app/src/main/java/com/firebase/uidemo/auth/AnonymousUpgradeActivity.java b/app/src/main/java/com/firebase/uidemo/auth/AnonymousUpgradeActivity.java
index db106193d..89ca92387 100644
--- a/app/src/main/java/com/firebase/uidemo/auth/AnonymousUpgradeActivity.java
+++ b/app/src/main/java/com/firebase/uidemo/auth/AnonymousUpgradeActivity.java
@@ -57,6 +57,16 @@ protected void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_anonymous_upgrade);
         ButterKnife.bind(this);
+
+        updateUI();
+
+        // Got here from AuthUIActivity, and we need to deal with a merge conflict
+        // Occurs after catching an email link
+        IdpResponse response = IdpResponse.fromResultIntent(getIntent());
+        if (response != null) {
+            handleSignInResult(RC_SIGN_IN, ErrorCodes.ANONYMOUS_UPGRADE_MERGE_CONFLICT,
+                    getIntent());
+        }
     }
 
     @OnClick(R.id.anon_sign_in)
@@ -81,10 +91,10 @@ public void onComplete(@NonNull Task<AuthResult> task) {
     public void startAuthUI() {
         List<AuthUI.IdpConfig> providers = ConfigurationUtils.getConfiguredProviders(this);
         Intent intent = AuthUI.getInstance().createSignInIntentBuilder()
-            .setLogo(R.drawable.firebase_auth_120dp)
-            .setAvailableProviders(providers)
-            .enableAnonymousUsersAutoUpgrade()
-            .build();
+                .setLogo(R.drawable.firebase_auth_120dp)
+                .setAvailableProviders(providers)
+                .enableAnonymousUsersAutoUpgrade()
+                .build();
         startActivityForResult(intent, RC_SIGN_IN);
     }
 
@@ -105,7 +115,8 @@ public void onComplete(@NonNull Task<AuthResult> task) {
                         updateUI();
 
                         if (task.isSuccessful()) {
-                            setStatus("Signed in as " + getUserIdentifier(task.getResult().getUser()));
+                            setStatus("Signed in as " + getUserIdentifier(task.getResult()
+                                    .getUser()));
                         } else {
                             Log.w(TAG, "Merge failed", task.getException());
                             setStatus("Failed to resolve merge conflict, see logs.");
@@ -129,6 +140,10 @@ public void onComplete(@NonNull Task<Void> task) {
     @Override
     protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
         super.onActivityResult(requestCode, resultCode, data);
+        handleSignInResult(requestCode, resultCode, data);
+    }
+
+    private void handleSignInResult(int requestCode, int resultCode, Intent data) {
         if (requestCode == RC_SIGN_IN) {
             IdpResponse response = IdpResponse.fromResultIntent(data);
             if (response == null) {
@@ -136,8 +151,10 @@ protected void onActivityResult(int requestCode, int resultCode, @Nullable Inten
                 return;
             }
             if (resultCode == RESULT_OK) {
-                setStatus("Signed in as " + getUserIdentifier(FirebaseAuth.getInstance().getCurrentUser()));
-            } else if (response.getError().getErrorCode() == ErrorCodes.ANONYMOUS_UPGRADE_MERGE_CONFLICT) {
+                setStatus("Signed in as " + getUserIdentifier(FirebaseAuth.getInstance()
+                        .getCurrentUser()));
+            } else if (response.getError().getErrorCode() == ErrorCodes
+                    .ANONYMOUS_UPGRADE_MERGE_CONFLICT) {
                 setStatus("Merge conflict: user already exists.");
                 mResolveMergeButton.setEnabled(true);
                 mPendingCredential = response.getCredentialForLinking();
diff --git a/app/src/main/java/com/firebase/uidemo/auth/AuthUiActivity.java b/app/src/main/java/com/firebase/uidemo/auth/AuthUiActivity.java
index a6efd38f6..668a11b0e 100644
--- a/app/src/main/java/com/firebase/uidemo/auth/AuthUiActivity.java
+++ b/app/src/main/java/com/firebase/uidemo/auth/AuthUiActivity.java
@@ -37,11 +37,13 @@
 import com.firebase.ui.auth.AuthUI.IdpConfig;
 import com.firebase.ui.auth.ErrorCodes;
 import com.firebase.ui.auth.IdpResponse;
+import com.firebase.ui.auth.util.ExtraConstants;
 import com.firebase.uidemo.R;
 import com.firebase.uidemo.util.ConfigurationUtils;
 import com.google.android.gms.common.Scopes;
 import com.google.android.gms.tasks.OnCompleteListener;
 import com.google.android.gms.tasks.Task;
+import com.google.firebase.auth.ActionCodeSettings;
 import com.google.firebase.auth.AuthResult;
 import com.google.firebase.auth.FirebaseAuth;
 
@@ -57,8 +59,10 @@ public class AuthUiActivity extends AppCompatActivity {
 
     private static final String GOOGLE_TOS_URL = "https://www.google.com/policies/terms/";
     private static final String FIREBASE_TOS_URL = "https://firebase.google.com/terms/";
-    private static final String GOOGLE_PRIVACY_POLICY_URL = "https://www.google.com/policies/privacy/";
-    private static final String FIREBASE_PRIVACY_POLICY_URL = "https://firebase.google.com/terms/analytics/#7_privacy";
+    private static final String GOOGLE_PRIVACY_POLICY_URL = "https://www.google" +
+            ".com/policies/privacy/";
+    private static final String FIREBASE_PRIVACY_POLICY_URL = "https://firebase.google" +
+            ".com/terms/analytics/#7_privacy";
 
     private static final int RC_SIGN_IN = 100;
 
@@ -69,6 +73,7 @@ public class AuthUiActivity extends AppCompatActivity {
     @BindView(R.id.twitter_provider) CheckBox mUseTwitterProvider;
     @BindView(R.id.github_provider) CheckBox mUseGitHubProvider;
     @BindView(R.id.email_provider) CheckBox mUseEmailProvider;
+    @BindView(R.id.email_link_provider) CheckBox mUseEmailLinkProvider;
     @BindView(R.id.phone_provider) CheckBox mUsePhoneProvider;
     @BindView(R.id.anonymous_provider) CheckBox mUseAnonymousProvider;
 
@@ -163,6 +168,23 @@ public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
             });
         }
 
+        mUseEmailLinkProvider.setOnCheckedChangeListener(new OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
+                flipPasswordProviderCheckbox(isChecked);
+            }
+        });
+
+        mUseEmailProvider.setOnCheckedChangeListener(new OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
+                flipEmailLinkProviderCheckbox(isChecked);
+            }
+        });
+
+        mUseEmailLinkProvider.setChecked(false);
+        mUseEmailProvider.setChecked(true);
+
         if (ConfigurationUtils.isGoogleMisconfigured(this)
                 || ConfigurationUtils.isFacebookMisconfigured(this)
                 || ConfigurationUtils.isTwitterMisconfigured(this)
@@ -173,11 +195,44 @@ public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
         if (AppCompatDelegate.getDefaultNightMode() == AppCompatDelegate.MODE_NIGHT_YES) {
             mDarkTheme.setChecked(true);
         }
+
+        catchEmailLinkSignIn();
+    }
+
+    public void catchEmailLinkSignIn() {
+        if (getIntent().getExtras() == null) {
+            return;
+        }
+        String link = getIntent().getExtras().getString(ExtraConstants.EMAIL_LINK_SIGN_IN);
+        if (link != null) {
+            signInWithEmailLink(link);
+        }
+    }
+
+    public void flipPasswordProviderCheckbox(boolean emailLinkProviderIsChecked) {
+        if (emailLinkProviderIsChecked) {
+            mUseEmailProvider.setChecked(false);
+        }
+    }
+
+    public void flipEmailLinkProviderCheckbox(boolean passwordProviderIsChecked) {
+        if (passwordProviderIsChecked) {
+            mUseEmailLinkProvider.setChecked(false);
+        }
     }
 
     @OnClick(R.id.sign_in)
     public void signIn() {
-        AuthUI.SignInIntentBuilder builder =  AuthUI.getInstance().createSignInIntentBuilder()
+        startActivityForResult(buildSignInIntent(/*link=*/null), RC_SIGN_IN);
+    }
+
+    public void signInWithEmailLink(@Nullable String link) {
+        startActivityForResult(buildSignInIntent(link), RC_SIGN_IN);
+    }
+
+    @NonNull
+    public Intent buildSignInIntent(@Nullable String link) {
+        AuthUI.SignInIntentBuilder builder = AuthUI.getInstance().createSignInIntentBuilder()
                 .setTheme(getSelectedTheme())
                 .setLogo(getSelectedLogo())
                 .setAvailableProviders(getSelectedProviders())
@@ -190,7 +245,17 @@ public void signIn() {
                     getSelectedPrivacyPolicyUrl());
         }
 
-        startActivityForResult(builder.build(), RC_SIGN_IN);
+        if (link != null) {
+            builder.setEmailLink(link);
+        }
+
+        FirebaseAuth auth = FirebaseAuth.getInstance();
+
+        if (auth.getCurrentUser() != null && auth.getCurrentUser().isAnonymous()) {
+            builder.enableAnonymousUsersAutoUpgrade();
+        }
+
+        return builder.build();
     }
 
     @OnClick(R.id.sign_in_silent)
@@ -220,7 +285,7 @@ protected void onActivityResult(int requestCode, int resultCode, @Nullable Inten
     protected void onResume() {
         super.onResume();
         FirebaseAuth auth = FirebaseAuth.getInstance();
-        if (auth.getCurrentUser() != null) {
+        if (auth.getCurrentUser() != null && getIntent().getExtras() == null) {
             startSignedInActivity(null);
             finish();
         }
@@ -246,6 +311,12 @@ private void handleSignInResponse(int resultCode, @Nullable Intent data) {
                 return;
             }
 
+            if (response.getError().getErrorCode() == ErrorCodes.ANONYMOUS_UPGRADE_MERGE_CONFLICT) {
+                Intent intent = new Intent(this, AnonymousUpgradeActivity.class).putExtra
+                        (ExtraConstants.IDP_RESPONSE, response);
+                startActivity(intent);
+            }
+
             showSnackbar(R.string.unknown_error);
             Log.e(TAG, "Sign-in error: ", response.getError());
         }
@@ -317,6 +388,20 @@ private List<IdpConfig> getSelectedProviders() {
                     .build());
         }
 
+        if (mUseEmailLinkProvider.isChecked()) {
+            ActionCodeSettings actionCodeSettings = ActionCodeSettings.newBuilder()
+                    .setAndroidPackageName("com.firebase.uidemo", true, null)
+                    .setHandleCodeInApp(true)
+                    .setUrl("https://google.com")
+                    .build();
+
+            selectedProviders.add(new IdpConfig.EmailBuilder()
+                    .setAllowNewAccounts(mAllowNewEmailAccounts.isChecked())
+                    .setActionCodeSettings(actionCodeSettings)
+                    .enableEmailLinkSignIn()
+                    .build());
+        }
+
         if (mUsePhoneProvider.isChecked()) {
             selectedProviders.add(new IdpConfig.PhoneBuilder().build());
         }
diff --git a/app/src/main/java/com/firebase/uidemo/auth/SignedInActivity.java b/app/src/main/java/com/firebase/uidemo/auth/SignedInActivity.java
index e0215891e..cd59b1a9e 100644
--- a/app/src/main/java/com/firebase/uidemo/auth/SignedInActivity.java
+++ b/app/src/main/java/com/firebase/uidemo/auth/SignedInActivity.java
@@ -55,6 +55,8 @@
 import butterknife.ButterKnife;
 import butterknife.OnClick;
 
+import static com.firebase.ui.auth.AuthUI.EMAIL_LINK_PROVIDER;
+
 public class SignedInActivity extends AppCompatActivity {
     private static final String TAG = "SignedInActivity";
 
@@ -187,6 +189,9 @@ private void populateProfile(@Nullable IdpResponse response) {
                     case PhoneAuthProvider.PROVIDER_ID:
                         providers.add(getString(R.string.providers_phone));
                         break;
+                    case EMAIL_LINK_PROVIDER:
+                        providers.add(getString(R.string.providers_email_link));
+                        break;
                     case FirebaseAuthProvider.PROVIDER_ID:
                         // Ignore this provider, it's not very meaningful
                         break;
diff --git a/app/src/main/java/com/firebase/uidemo/util/ConfigurationUtils.java b/app/src/main/java/com/firebase/uidemo/util/ConfigurationUtils.java
index 63809340e..04049ff1d 100644
--- a/app/src/main/java/com/firebase/uidemo/util/ConfigurationUtils.java
+++ b/app/src/main/java/com/firebase/uidemo/util/ConfigurationUtils.java
@@ -6,6 +6,7 @@
 
 import com.firebase.ui.auth.AuthUI;
 import com.firebase.uidemo.R;
+import com.google.firebase.auth.ActionCodeSettings;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -49,8 +50,6 @@ public static boolean isGitHubMisconfigured(@NonNull Context context) {
     @NonNull
     public static List<AuthUI.IdpConfig> getConfiguredProviders(@NonNull Context context) {
         List<AuthUI.IdpConfig> providers = new ArrayList<>();
-        providers.add(new AuthUI.IdpConfig.EmailBuilder().build());
-        providers.add(new AuthUI.IdpConfig.PhoneBuilder().build());
 
         if (!isGoogleMisconfigured(context)) {
             providers.add(new AuthUI.IdpConfig.GoogleBuilder().build());
@@ -68,6 +67,22 @@ public static List<AuthUI.IdpConfig> getConfiguredProviders(@NonNull Context con
             providers.add(new AuthUI.IdpConfig.GitHubBuilder().build());
         }
 
+        ActionCodeSettings actionCodeSettings = ActionCodeSettings.newBuilder()
+                .setAndroidPackageName("com.firebase.uidemo", true, null)
+                .setHandleCodeInApp(true)
+                .setUrl("https://google.com")
+                .build();
+
+        providers.add(new AuthUI.IdpConfig.EmailBuilder()
+                .setAllowNewAccounts(true)
+                .enableEmailLinkSignIn()
+                .setActionCodeSettings(actionCodeSettings)
+                .build());
+
+
+        providers.add(new AuthUI.IdpConfig.PhoneBuilder().build());
+
+
         return providers;
     }
 }
diff --git a/app/src/main/res/layout/auth_ui_layout.xml b/app/src/main/res/layout/auth_ui_layout.xml
index 6f99974a0..7edc9f76f 100644
--- a/app/src/main/res/layout/auth_ui_layout.xml
+++ b/app/src/main/res/layout/auth_ui_layout.xml
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<android.support.design.widget.CoordinatorLayout
-    xmlns:android="http://schemas.android.com/apk/res/android"
+<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/root"
     android:layout_width="match_parent"
@@ -15,11 +14,11 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_marginLeft="24dp"
-            android:layout_marginRight="24dp"
             android:layout_marginTop="16dp"
+            android:layout_marginRight="24dp"
             android:layout_marginBottom="16dp"
-            android:paddingBottom="32dp"
-            android:orientation="vertical">
+            android:orientation="vertical"
+            android:paddingBottom="32dp">
 
             <TextView
                 style="@style/Base.TextAppearance.AppCompat.Headline"
@@ -34,8 +33,8 @@
                 style="@style/Widget.AppCompat.Button.Colored"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
-                android:layout_marginTop="16dp"
                 android:layout_gravity="center"
+                android:layout_marginTop="16dp"
                 android:text="@string/sign_in_start" />
 
             <Button
@@ -43,8 +42,8 @@
                 style="@style/Widget.AppCompat.Button.Colored"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
-                android:layout_marginBottom="16dp"
                 android:layout_gravity="center"
+                android:layout_marginBottom="16dp"
                 android:text="@string/sign_in_silent" />
 
             <TextView
@@ -89,6 +88,13 @@
                 android:checked="true"
                 android:text="@string/providers_email" />
 
+            <CheckBox
+                android:id="@+id/email_link_provider"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:checked="true"
+                android:text="@string/providers_email_link" />
+
             <CheckBox
                 android:id="@+id/phone_provider"
                 android:layout_width="wrap_content"
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 7900a7013..3f34c209c 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -26,6 +26,7 @@
     <string name="providers_github">GitHub</string>
     <string name="providers_twitter">Twitter</string>
     <string name="providers_email">Email</string>
+    <string name="providers_email_link">Email link</string>
     <string name="providers_phone">Phone</string>
     <string name="providers_anonymous">Anonymous</string>
 
diff --git a/auth/src/main/AndroidManifest.xml b/auth/src/main/AndroidManifest.xml
index 0e718cf9a..533595e8f 100644
--- a/auth/src/main/AndroidManifest.xml
+++ b/auth/src/main/AndroidManifest.xml
@@ -65,6 +65,19 @@
             android:exported="false"
             android:windowSoftInputMode="adjustResize" />
 
+        <activity
+            android:name=".ui.email.WelcomeBackEmailLinkPrompt"
+            android:label="@string/fui_title_welcome_back_password_prompt"
+            android:exported="false"
+            android:windowSoftInputMode="adjustResize" />
+
+        <activity
+            android:name=".ui.email.EmailLinkCatcherActivity"
+            android:exported="false"
+            android:label=""
+            android:theme="@style/FirebaseUI.Transparent"
+            android:windowSoftInputMode="adjustResize" />
+
         <activity
             android:name=".ui.idp.AuthMethodPickerActivity"
             android:label="@string/fui_default_toolbar_title"
diff --git a/auth/src/main/java/com/firebase/ui/auth/AuthUI.java b/auth/src/main/java/com/firebase/ui/auth/AuthUI.java
index d358abd36..7916b8d79 100644
--- a/auth/src/main/java/com/firebase/ui/auth/AuthUI.java
+++ b/auth/src/main/java/com/firebase/ui/auth/AuthUI.java
@@ -54,6 +54,7 @@
 import com.google.android.gms.tasks.Task;
 import com.google.android.gms.tasks.Tasks;
 import com.google.firebase.FirebaseApp;
+import com.google.firebase.auth.ActionCodeSettings;
 import com.google.firebase.auth.AuthCredential;
 import com.google.firebase.auth.AuthResult;
 import com.google.firebase.auth.EmailAuthProvider;
@@ -87,7 +88,8 @@
  * {@link AuthUI#getInstance(FirebaseApp)} instead, passing the appropriate app instance.
  * <p>
  * <p>
- * See the <a href="https://github.com/firebase/FirebaseUI-Android/blob/master/auth/README.md#table-of-contents">README</a>
+ * See the
+ * <a href="https://github.com/firebase/FirebaseUI-Android/blob/master/auth/README.md#table-of-contents">README</a>
  * for examples on how to get started with FirebaseUI Auth.
  */
 public final class AuthUI {
@@ -100,18 +102,7 @@ public final class AuthUI {
      */
     @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
     public static final String ANONYMOUS_PROVIDER = "anonymous";
-
-    @StringDef({
-                       GoogleAuthProvider.PROVIDER_ID,
-                       FacebookAuthProvider.PROVIDER_ID,
-                       TwitterAuthProvider.PROVIDER_ID,
-                       GithubAuthProvider.PROVIDER_ID,
-                       EmailAuthProvider.PROVIDER_ID,
-                       PhoneAuthProvider.PROVIDER_ID,
-                       ANONYMOUS_PROVIDER
-               })
-    @Retention(RetentionPolicy.SOURCE)
-    public @interface SupportedProvider {}
+    public static final String EMAIL_LINK_PROVIDER = EmailAuthProvider.EMAIL_LINK_SIGN_IN_METHOD;
 
     /**
      * Default value for logo resource, omits the logo from the {@link AuthMethodPickerActivity}.
@@ -129,7 +120,8 @@ public final class AuthUI {
                     GithubAuthProvider.PROVIDER_ID,
                     EmailAuthProvider.PROVIDER_ID,
                     PhoneAuthProvider.PROVIDER_ID,
-                    ANONYMOUS_PROVIDER
+                    ANONYMOUS_PROVIDER,
+                    EMAIL_LINK_PROVIDER
             )));
 
     /**
@@ -165,18 +157,18 @@ private AuthUI(FirebaseApp app) {
         mAuth.useAppLanguage();
     }
 
-    @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
-    public static void setApplicationContext(@NonNull Context context) {
-        sApplicationContext = Preconditions.checkNotNull(context, "App context cannot be null.")
-                .getApplicationContext();
-    }
-
     @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
     @NonNull
     public static Context getApplicationContext() {
         return sApplicationContext;
     }
 
+    @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+    public static void setApplicationContext(@NonNull Context context) {
+        sApplicationContext = Preconditions.checkNotNull(context, "App context cannot be null.")
+                .getApplicationContext();
+    }
+
     /**
      * Retrieves the {@link AuthUI} instance associated with the default app, as returned by {@code
      * FirebaseApp.getInstance()}.
@@ -204,6 +196,21 @@ public static AuthUI getInstance(@NonNull FirebaseApp app) {
         return authUi;
     }
 
+    /**
+     * Returns true if AuthUI can handle the intent.
+     * <p>
+     * AuthUI handle the intent when the embedded data is an email link. If it is, you can then
+     * specify the link in {@link SignInIntentBuilder#setEmailLink(String)} before starting AuthUI
+     * and it will be handled immediately.
+     */
+    public static boolean canHandleIntent(@NonNull Intent intent) {
+        if (intent == null || intent.getData() == null) {
+            return false;
+        }
+        String link = intent.getData().toString();
+        return FirebaseAuth.getInstance().isSignInWithEmailLink(link);
+    }
+
     /**
      * Default theme used by {@link SignInIntentBuilder#setTheme(int)} if no theme customization is
      * required.
@@ -213,6 +220,34 @@ public static int getDefaultTheme() {
         return R.style.FirebaseUI;
     }
 
+    /**
+     * Make a list of {@link Credential} from a FirebaseUser. Useful for deleting Credentials, not
+     * for saving since we don't have access to the password.
+     */
+    private static List<Credential> getCredentialsFromFirebaseUser(@NonNull FirebaseUser user) {
+        if (TextUtils.isEmpty(user.getEmail()) && TextUtils.isEmpty(user.getPhoneNumber())) {
+            return Collections.emptyList();
+        }
+
+        List<Credential> credentials = new ArrayList<>();
+        for (UserInfo userInfo : user.getProviderData()) {
+            if (FirebaseAuthProvider.PROVIDER_ID.equals(userInfo.getProviderId())) {
+                continue;
+            }
+
+            String type = ProviderUtils.providerIdToAccountType(userInfo.getProviderId());
+            if (type == null) {
+                // Since the account type is null, we've got an email credential. Adding a fake
+                // password is the only way to tell Smart Lock that this is an email credential.
+                credentials.add(CredentialUtils.buildCredentialOrThrow(user, "pass", null));
+            } else {
+                credentials.add(CredentialUtils.buildCredentialOrThrow(user, null, type));
+            }
+        }
+
+        return credentials;
+    }
+
     /**
      * Signs the user in without any UI if possible. If this operation fails, you can safely start a
      * UI-based sign-in flow knowing it is required.
@@ -262,7 +297,8 @@ public Task<AuthResult> silentSignIn(@NonNull Context context,
                         // one, meaning Smart Lock won't have to show the picker UI.
                         .setPasswordLoginSupported(email != null)
                         .setAccountTypes(google == null ? null :
-                                ProviderUtils.providerIdToAccountType(GoogleAuthProvider.PROVIDER_ID))
+                                ProviderUtils.providerIdToAccountType(GoogleAuthProvider
+                                        .PROVIDER_ID))
                         .build())
                 .continueWithTask(new Continuation<CredentialRequestResponse, Task<AuthResult>>() {
                     @Override
@@ -277,11 +313,14 @@ public Task<AuthResult> then(@NonNull Task<CredentialRequestResponse> task) {
                                             .setAccountName(email)
                                             .build())
                                     .silentSignIn()
-                                    .continueWithTask(new Continuation<GoogleSignInAccount, Task<AuthResult>>() {
+                                    .continueWithTask(new Continuation<GoogleSignInAccount,
+                                            Task<AuthResult>>() {
                                         @Override
-                                        public Task<AuthResult> then(@NonNull Task<GoogleSignInAccount> task) {
-                                            AuthCredential authCredential = GoogleAuthProvider.getCredential(
-                                                    task.getResult().getIdToken(), null);
+                                        public Task<AuthResult> then(
+                                                @NonNull Task<GoogleSignInAccount> task) {
+                                            AuthCredential authCredential = GoogleAuthProvider
+                                                    .getCredential(
+                                                            task.getResult().getIdToken(), null);
                                             return mAuth.signInWithCredential(authCredential);
                                         }
                                     });
@@ -311,7 +350,8 @@ public Void then(@NonNull Task<Void> task) {
                         // to fail (see Issue 1156).
                         Exception e = task.getException();
                         if (e instanceof ApiException
-                                && ((ApiException) e).getStatusCode() == CommonStatusCodes.CANCELED) {
+                                && ((ApiException) e).getStatusCode() == CommonStatusCodes
+                                .CANCELED) {
                             Log.w(TAG, "Could not disable auto-sign in, maybe there are no " +
                                     "SmartLock accounts available?", e);
                             return null;
@@ -371,7 +411,8 @@ public Void then(@NonNull Task<Void> task) {
                                 Exception e = task.getException();
                                 Throwable t = e == null ? null : e.getCause();
                                 if (!(t instanceof ApiException)
-                                        || ((ApiException) t).getStatusCode() != CommonStatusCodes.CANCELED) {
+                                        || ((ApiException) t).getStatusCode() !=
+                                        CommonStatusCodes.CANCELED) {
                                     // Only propagate the exception if it isn't an invalid account
                                     // one. This can occur if we failed to save the credential or it
                                     // was deleted elsewhere. However, a lack of stored credential
@@ -403,34 +444,6 @@ private Task<Void> signOutIdps(@NonNull Context context) {
         return GoogleSignIn.getClient(context, GoogleSignInOptions.DEFAULT_SIGN_IN).signOut();
     }
 
-    /**
-     * Make a list of {@link Credential} from a FirebaseUser. Useful for deleting Credentials, not
-     * for saving since we don't have access to the password.
-     */
-    private static List<Credential> getCredentialsFromFirebaseUser(@NonNull FirebaseUser user) {
-        if (TextUtils.isEmpty(user.getEmail()) && TextUtils.isEmpty(user.getPhoneNumber())) {
-            return Collections.emptyList();
-        }
-
-        List<Credential> credentials = new ArrayList<>();
-        for (UserInfo userInfo : user.getProviderData()) {
-            if (FirebaseAuthProvider.PROVIDER_ID.equals(userInfo.getProviderId())) {
-                continue;
-            }
-
-            String type = ProviderUtils.providerIdToAccountType(userInfo.getProviderId());
-            if (type == null) {
-                // Since the account type is null, we've got an email credential. Adding a fake
-                // password is the only way to tell Smart Lock that this is an email credential.
-                credentials.add(CredentialUtils.buildCredentialOrThrow(user, "pass", null));
-            } else {
-                credentials.add(CredentialUtils.buildCredentialOrThrow(user, null, type));
-            }
-        }
-
-        return credentials;
-    }
-
     /**
      * Starts the process of creating a sign in intent, with the mandatory application context
      * parameter.
@@ -440,6 +453,21 @@ public SignInIntentBuilder createSignInIntentBuilder() {
         return new SignInIntentBuilder();
     }
 
+    @StringDef({
+            GoogleAuthProvider.PROVIDER_ID,
+            FacebookAuthProvider.PROVIDER_ID,
+            TwitterAuthProvider.PROVIDER_ID,
+            GithubAuthProvider.PROVIDER_ID,
+            EmailAuthProvider.PROVIDER_ID,
+            PhoneAuthProvider.PROVIDER_ID,
+            ANONYMOUS_PROVIDER,
+            EmailAuthProvider.EMAIL_LINK_SIGN_IN_METHOD
+    })
+
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface SupportedProvider {
+    }
+
     /**
      * Configuration for an identity provider.
      */
@@ -525,8 +553,8 @@ public String toString() {
          * @see SignInIntentBuilder#setAvailableProviders(List)
          */
         public static class Builder {
-            @SupportedProvider private final String mProviderId;
             private final Bundle mParams = new Bundle();
+            @SupportedProvider private String mProviderId;
 
             protected Builder(@SupportedProvider @NonNull String providerId) {
                 if (!SUPPORTED_PROVIDERS.contains(providerId)) {
@@ -541,6 +569,11 @@ protected final Bundle getParams() {
                 return mParams;
             }
 
+            @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+            protected void setProviderId(@NonNull String providerId) {
+                mProviderId = providerId;
+            }
+
             @CallSuper
             @NonNull
             public IdpConfig build() {
@@ -557,7 +590,7 @@ public EmailBuilder() {
             }
 
             /**
-             * Enables or disables creating new accounts in the email sign in flow.
+             * Enables or disables creating new accounts in the email sign in flows.
              * <p>
              * Account creation is enabled by default.
              */
@@ -578,6 +611,36 @@ public EmailBuilder setRequireName(boolean requireName) {
                 getParams().putBoolean(ExtraConstants.REQUIRE_NAME, requireName);
                 return this;
             }
+
+            @NonNull
+            public EmailBuilder enableEmailLinkSignIn() {
+                setProviderId(EMAIL_LINK_PROVIDER);
+                return this;
+            }
+
+            @NonNull
+            public EmailBuilder setActionCodeSettings(ActionCodeSettings actionCodeSettings) {
+                getParams().putParcelable(ExtraConstants.ACTION_CODE_SETTINGS, actionCodeSettings);
+                return this;
+            }
+
+            @Override
+            public IdpConfig build() {
+                if (super.mProviderId.equals(EMAIL_LINK_PROVIDER)) {
+                    ActionCodeSettings actionCodeSettings = getParams().getParcelable
+                            (ExtraConstants.ACTION_CODE_SETTINGS);
+                    Preconditions.checkNotNull(actionCodeSettings, "ActionCodeSettings cannot be " +
+                            "null when using email link sign in.");
+                    if (actionCodeSettings != null && !actionCodeSettings.canHandleCodeInApp()) {
+                        // Pre-emptively fail if actionCodeSettings are misconfigured. This would
+                        // have happened when calling sendSignInLinkToEmail
+                        throw new IllegalArgumentException(
+                                "You must set canHandleCodeInApp in your ActionCodeSettings to " +
+                                        "true for Email-Link Sign-in.");
+                    }
+                }
+                return super.build();
+            }
         }
 
         /**
@@ -673,7 +736,7 @@ public PhoneBuilder setDefaultCountryIso(@NonNull String iso) {
              * @param whitelistedCountries a non empty case insensitive list of country codes
              *                             and/or isos to be whitelisted
              * @throws IllegalArgumentException if an empty whitelist is provided.
-             * @throws NullPointerException if a null whitelist is provided.
+             * @throws NullPointerException     if a null whitelist is provided.
              */
             public PhoneBuilder setWhitelistedCountries(
                     @NonNull List<String> whitelistedCountries) {
@@ -686,7 +749,8 @@ public PhoneBuilder setWhitelistedCountries(
                 String message = "Invalid argument: Only non-%s whitelists are valid. " +
                         "To specify no whitelist, do not call this method.";
                 Preconditions.checkNotNull(whitelistedCountries, String.format(message, "null"));
-                Preconditions.checkArgument(!whitelistedCountries.isEmpty(), String.format(message, "empty"));
+                Preconditions.checkArgument(!whitelistedCountries.isEmpty(), String.format
+                        (message, "empty"));
 
                 addCountriesToBundle(whitelistedCountries, ExtraConstants.WHITELISTED_COUNTRIES);
                 return this;
@@ -709,7 +773,7 @@ public PhoneBuilder setWhitelistedCountries(
              * @param blacklistedCountries a non empty case insensitive list of country codes
              *                             and/or isos to be blacklisted
              * @throws IllegalArgumentException if an empty blacklist is provided.
-             * @throws NullPointerException if a null blacklist is provided.
+             * @throws NullPointerException     if a null blacklist is provided.
              */
             public PhoneBuilder setBlacklistedCountries(
                     @NonNull List<String> blacklistedCountries) {
@@ -722,7 +786,8 @@ public PhoneBuilder setBlacklistedCountries(
                 String message = "Invalid argument: Only non-%s blacklists are valid. " +
                         "To specify no blacklist, do not call this method.";
                 Preconditions.checkNotNull(blacklistedCountries, String.format(message, "null"));
-                Preconditions.checkArgument(!blacklistedCountries.isEmpty(), String.format(message, "empty"));
+                Preconditions.checkArgument(!blacklistedCountries.isEmpty(), String.format
+                        (message, "empty"));
 
                 addCountriesToBundle(blacklistedCountries, ExtraConstants.BLACKLISTED_COUNTRIES);
                 return this;
@@ -929,7 +994,9 @@ public FacebookBuilder() {
                 Preconditions.checkConfigured(getApplicationContext(),
                         "Facebook provider unconfigured. Make sure to add a" +
                                 " `facebook_application_id` string. See the docs for more info:" +
-                                " https://github.com/firebase/FirebaseUI-Android/blob/master/auth/README.md#facebook",
+                                " https://github" +
+                                ".com/firebase/FirebaseUI-Android/blob/master/auth/README" +
+                                ".md#facebook",
                         R.string.facebook_application_id);
                 if (getApplicationContext().getString(R.string.facebook_login_protocol_scheme)
                         .equals("fbYOUR_APP_ID")) {
@@ -965,7 +1032,9 @@ public TwitterBuilder() {
                 Preconditions.checkConfigured(getApplicationContext(),
                         "Twitter provider unconfigured. Make sure to add your key and secret." +
                                 " See the docs for more info:" +
-                                " https://github.com/firebase/FirebaseUI-Android/blob/master/auth/README.md#twitter",
+                                " https://github" +
+                                ".com/firebase/FirebaseUI-Android/blob/master/auth/README" +
+                                ".md#twitter",
                         R.string.twitter_consumer_key,
                         R.string.twitter_consumer_secret);
             }
@@ -985,9 +1054,12 @@ public GitHubBuilder() {
                                     "'com.firebaseui:firebase-ui-auth-github:VERSION' dependency?");
                 }
                 Preconditions.checkConfigured(getApplicationContext(),
-                        "GitHub provider unconfigured. Make sure to add your client id and secret." +
+                        "GitHub provider unconfigured. Make sure to add your client id and secret" +
+                                "." +
                                 " See the docs for more info:" +
-                                " https://github.com/firebase/FirebaseUI-Android/blob/master/auth/README.md#github",
+                                " https://github" +
+                                ".com/firebase/FirebaseUI-Android/blob/master/auth/README" +
+                                ".md#github",
                         R.string.firebase_web_host,
                         R.string.github_client_id,
                         R.string.github_client_secret);
@@ -995,7 +1067,8 @@ public GitHubBuilder() {
 
             /**
              * Specifies the additional permissions to be requested. Available permissions can be
-             * found <ahref="https://developer.github.com/apps/building-oauth-apps/scopes-for-oauth-apps/#available-scopes">here</a>.
+             * found
+             * <ahref="https://developer.github.com/apps/building-oauth-apps/scopes-for-oauth-apps/#available-scopes">here</a>.
              */
             @NonNull
             public GitHubBuilder setPermissions(@NonNull List<String> permissions) {
@@ -1020,9 +1093,9 @@ public AnonymousBuilder() {
      */
     @SuppressWarnings(value = "unchecked")
     private abstract class AuthIntentBuilder<T extends AuthIntentBuilder> {
+        final List<IdpConfig> mProviders = new ArrayList<>();
         int mLogo = NO_LOGO;
         int mTheme = getDefaultTheme();
-        final List<IdpConfig> mProviders = new ArrayList<>();
         String mTosUrl;
         String mPrivacyPolicyUrl;
         boolean mAlwaysShowProviderChoice = false;
@@ -1188,12 +1261,23 @@ public Intent build() {
      */
     public final class SignInIntentBuilder extends AuthIntentBuilder<SignInIntentBuilder> {
 
+        private String mEmailLink;
         private boolean mEnableAnonymousUpgrade;
 
         private SignInIntentBuilder() {
             super();
         }
 
+        /**
+         * Specifies the email link to be used for sign in. When set, a sign in attempt will be
+         * made immediately.
+         */
+        @NonNull
+        public SignInIntentBuilder setEmailLink(@NonNull final String emailLink) {
+            mEmailLink = emailLink;
+            return this;
+        }
+
         /**
          * Enables upgrading anonymous accounts to full accounts during the sign-in flow.
          * This is disabled by default.
@@ -1216,7 +1300,8 @@ protected FlowParameters getFlowParams() {
                     mEnableCredentials,
                     mEnableHints,
                     mEnableAnonymousUpgrade,
-                    mAlwaysShowProviderChoice);
+                    mAlwaysShowProviderChoice,
+                    mEmailLink);
         }
     }
 }
diff --git a/auth/src/main/java/com/firebase/ui/auth/ErrorCodes.java b/auth/src/main/java/com/firebase/ui/auth/ErrorCodes.java
index fca246ac4..e0166d689 100644
--- a/auth/src/main/java/com/firebase/ui/auth/ErrorCodes.java
+++ b/auth/src/main/java/com/firebase/ui/auth/ErrorCodes.java
@@ -11,55 +11,44 @@
  * Error codes for failed sign-in attempts.
  */
 public final class ErrorCodes {
-    /**
-     * Valid codes that can be returned from {@link FirebaseUiException#getErrorCode()}.
-     */
-    @IntDef({
-                    UNKNOWN_ERROR,
-                    NO_NETWORK,
-                    PLAY_SERVICES_UPDATE_CANCELLED,
-                    DEVELOPER_ERROR,
-                    PROVIDER_ERROR,
-                    ANONYMOUS_UPGRADE_MERGE_CONFLICT,
-                    EMAIL_MISMATCH_ERROR
-            })
-    @Retention(RetentionPolicy.SOURCE)
-    public @interface Code {}
-
     /**
      * An unknown error has occurred.
      */
     public static final int UNKNOWN_ERROR = 0;
-
     /**
      * Sign in failed due to lack of network connection.
      */
     public static final int NO_NETWORK = 1;
-
     /**
      * A required update to Play Services was cancelled by the user.
      */
     public static final int PLAY_SERVICES_UPDATE_CANCELLED = 2;
-
     /**
      * A sign-in operation couldn't be completed due to a developer error.
      */
     public static final int DEVELOPER_ERROR = 3;
-
     /**
      * An external sign-in provider error occurred.
      */
     public static final int PROVIDER_ERROR = 4;
-
     /**
      * Anonymous account linking failed.
      */
     public static final int ANONYMOUS_UPGRADE_MERGE_CONFLICT = 5;
-
     /**
      * Signing in with a different email in the WelcomeBackIdp flow.
      */
     public static final int EMAIL_MISMATCH_ERROR = 6;
+    /**
+     * Attempting to sign in with an invalid email link.
+     */
+    public static final int INVALID_EMAIL_LINK_ERROR = 7;
+
+    /**
+     * Attempting to open an email link from a different device.
+     */
+    public static final int EMAIL_LINK_WRONG_DEVICE_ERROR = 8;
+
 
 
     private ErrorCodes() {
@@ -85,8 +74,30 @@ public static String toFriendlyMessage(@Code int code) {
             case EMAIL_MISMATCH_ERROR:
                 return "You are are attempting to sign in a different email than previously " +
                         "provided";
+            case INVALID_EMAIL_LINK_ERROR:
+                return "You are are attempting to sign in with an invalid email link";
+            case EMAIL_LINK_WRONG_DEVICE_ERROR:
+                return "You must open the email link on the same device.";
             default:
                 throw new IllegalArgumentException("Unknown code: " + code);
         }
     }
+
+    /**
+     * Valid codes that can be returned from {@link FirebaseUiException#getErrorCode()}.
+     */
+    @IntDef({
+            UNKNOWN_ERROR,
+            NO_NETWORK,
+            PLAY_SERVICES_UPDATE_CANCELLED,
+            DEVELOPER_ERROR,
+            PROVIDER_ERROR,
+            ANONYMOUS_UPGRADE_MERGE_CONFLICT,
+            EMAIL_MISMATCH_ERROR,
+            INVALID_EMAIL_LINK_ERROR,
+            EMAIL_LINK_WRONG_DEVICE_ERROR
+    })
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface Code {
+    }
 }
diff --git a/auth/src/main/java/com/firebase/ui/auth/IdpResponse.java b/auth/src/main/java/com/firebase/ui/auth/IdpResponse.java
index 4566e055d..3aa400cab 100644
--- a/auth/src/main/java/com/firebase/ui/auth/IdpResponse.java
+++ b/auth/src/main/java/com/firebase/ui/auth/IdpResponse.java
@@ -111,12 +111,6 @@ public static IdpResponse fromResultIntent(@Nullable Intent resultIntent) {
         }
     }
 
-    @NonNull
-    @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
-    public IdpResponse withResult(AuthResult result) {
-        return mutate().setNewUser(result.getAdditionalUserInfo().isNewUser()).build();
-    }
-
     @NonNull
     @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
     public static IdpResponse from(@NonNull Exception e) {
@@ -135,6 +129,12 @@ public static Intent getErrorIntent(@NonNull Exception e) {
         return from(e).toIntent();
     }
 
+    @NonNull
+    @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+    public IdpResponse withResult(AuthResult result) {
+        return mutate().setNewUser(result.getAdditionalUserInfo().isNewUser()).build();
+    }
+
     @NonNull
     @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
     public Intent toIntent() {
@@ -253,7 +253,8 @@ public void writeToParcel(Parcel dest, int flags) {
             if (oos != null) {
                 try {
                     oos.close();
-                } catch (IOException ignored) {}
+                } catch (IOException ignored) {
+                }
             }
         }
 
@@ -271,7 +272,8 @@ public boolean equals(Object o) {
                 && (mToken == null ? response.mToken == null : mToken.equals(response.mToken))
                 && (mSecret == null ? response.mSecret == null : mSecret.equals(response.mSecret))
                 && (mIsNewUser == response.mIsNewUser)
-                && (mException == null ? response.mException == null : mException.equals(response.mException))
+                && (mException == null ? response.mException == null : mException.equals(response
+                .mException))
                 && (mPendingCredential == null ? response.mPendingCredential == null :
                 mPendingCredential.getProvider().equals(response.mPendingCredential.getProvider()));
     }
@@ -283,7 +285,8 @@ public int hashCode() {
         result = 31 * result + (mSecret == null ? 0 : mSecret.hashCode());
         result = 31 * result + (mIsNewUser ? 1 : 0);
         result = 31 * result + (mException == null ? 0 : mException.hashCode());
-        result = 31 * result + (mPendingCredential == null ? 0 : mPendingCredential.getProvider().hashCode());
+        result = 31 * result + (mPendingCredential == null ? 0 : mPendingCredential.getProvider()
+                .hashCode());
         return result;
     }
 
@@ -343,7 +346,8 @@ public Builder setSecret(String secret) {
 
         public IdpResponse build() {
             if (mPendingCredential != null) {
-                return new IdpResponse(mPendingCredential, new FirebaseUiException(ErrorCodes.ANONYMOUS_UPGRADE_MERGE_CONFLICT));
+                return new IdpResponse(mPendingCredential, new FirebaseUiException(ErrorCodes
+                        .ANONYMOUS_UPGRADE_MERGE_CONFLICT));
             }
 
             String providerId = mUser.getProviderId();
diff --git a/auth/src/main/java/com/firebase/ui/auth/KickoffActivity.java b/auth/src/main/java/com/firebase/ui/auth/KickoffActivity.java
index e1ad3104d..c1c5d9d58 100644
--- a/auth/src/main/java/com/firebase/ui/auth/KickoffActivity.java
+++ b/auth/src/main/java/com/firebase/ui/auth/KickoffActivity.java
@@ -14,6 +14,7 @@
 import com.firebase.ui.auth.data.remote.SignInKickstarter;
 import com.firebase.ui.auth.ui.InvisibleActivityBase;
 import com.firebase.ui.auth.util.ExtraConstants;
+import com.firebase.ui.auth.viewmodel.RequestCodes;
 import com.firebase.ui.auth.viewmodel.ResourceObserver;
 import com.google.android.gms.common.GoogleApiAvailability;
 import com.google.android.gms.tasks.OnFailureListener;
@@ -44,7 +45,8 @@ protected void onFailure(@NonNull Exception e) {
                     finish(RESULT_CANCELED, null);
                 } else if (e instanceof FirebaseAuthAnonymousUpgradeException) {
                     IdpResponse res = ((FirebaseAuthAnonymousUpgradeException) e).getResponse();
-                    finish(RESULT_CANCELED, new Intent().putExtra(ExtraConstants.IDP_RESPONSE, res));
+                    finish(RESULT_CANCELED, new Intent().putExtra(ExtraConstants.IDP_RESPONSE,
+                            res));
                 } else {
                     finish(RESULT_CANCELED, IdpResponse.getErrorIntent(e));
                 }
@@ -56,7 +58,9 @@ protected void onFailure(@NonNull Exception e) {
                 .addOnSuccessListener(this, new OnSuccessListener<Void>() {
                     @Override
                     public void onSuccess(Void aVoid) {
-                        if (savedInstanceState != null) { return; }
+                        if (savedInstanceState != null) {
+                            return;
+                        }
 
                         if (isOffline()) {
                             finish(RESULT_CANCELED, IdpResponse.getErrorIntent(
@@ -78,9 +82,23 @@ public void onFailure(@NonNull Exception e) {
     @Override
     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
         super.onActivityResult(requestCode, resultCode, data);
+
+        if (requestCode == RequestCodes.EMAIL_FLOW
+                && (resultCode == RequestCodes.EMAIL_LINK_WRONG_DEVICE_FLOW
+                || resultCode == RequestCodes.EMAIL_LINK_INVALID_LINK_FLOW)) {
+            invalidateEmailLink();
+        }
+
         mKickstarter.onActivityResult(requestCode, resultCode, data);
     }
 
+    public void invalidateEmailLink() {
+        FlowParameters flowParameters = getFlowParams();
+        flowParameters.emailLink = null;
+        setIntent(getIntent().putExtra(ExtraConstants.FLOW_PARAMS,
+                flowParameters));
+    }
+
     /**
      * Check if there is an active or soon-to-be-active network connection.
      *
diff --git a/auth/src/main/java/com/firebase/ui/auth/data/model/FlowParameters.java b/auth/src/main/java/com/firebase/ui/auth/data/model/FlowParameters.java
index c05398360..68b461f2d 100644
--- a/auth/src/main/java/com/firebase/ui/auth/data/model/FlowParameters.java
+++ b/auth/src/main/java/com/firebase/ui/auth/data/model/FlowParameters.java
@@ -36,6 +36,42 @@
  */
 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 public class FlowParameters implements Parcelable {
+
+    public static final Creator<FlowParameters> CREATOR = new Creator<FlowParameters>() {
+        @Override
+        public FlowParameters createFromParcel(Parcel in) {
+            String appName = in.readString();
+            List<IdpConfig> providerInfo = in.createTypedArrayList(IdpConfig.CREATOR);
+            int themeId = in.readInt();
+            int logoId = in.readInt();
+            String termsOfServiceUrl = in.readString();
+            String privacyPolicyUrl = in.readString();
+            boolean enableCredentials = in.readInt() != 0;
+            boolean enableHints = in.readInt() != 0;
+            boolean enableAnonymousUpgrade = in.readInt() != 0;
+            boolean alwaysShowProviderChoice = in.readInt() != 0;
+            String emailLink = in.readString();
+
+            return new FlowParameters(
+                    appName,
+                    providerInfo,
+                    themeId,
+                    logoId,
+                    termsOfServiceUrl,
+                    privacyPolicyUrl,
+                    enableCredentials,
+                    enableHints,
+                    enableAnonymousUpgrade,
+                    alwaysShowProviderChoice,
+                    emailLink);
+        }
+
+        @Override
+        public FlowParameters[] newArray(int size) {
+            return new FlowParameters[size];
+        }
+    };
+
     @NonNull
     public final String appName;
 
@@ -54,6 +90,9 @@ public class FlowParameters implements Parcelable {
     @Nullable
     public final String privacyPolicyUrl;
 
+    @Nullable
+    public String emailLink;
+
     public final boolean enableCredentials;
     public final boolean enableHints;
     public final boolean enableAnonymousUpgrade;
@@ -69,7 +108,8 @@ public FlowParameters(
             boolean enableCredentials,
             boolean enableHints,
             boolean enableAnonymousUpgrade,
-            boolean alwaysShowProviderChoice) {
+            boolean alwaysShowProviderChoice,
+            @Nullable String emailLink) {
         this.appName = Preconditions.checkNotNull(appName, "appName cannot be null");
         this.providers = Collections.unmodifiableList(
                 Preconditions.checkNotNull(providers, "providers cannot be null"));
@@ -81,6 +121,7 @@ public FlowParameters(
         this.enableHints = enableHints;
         this.enableAnonymousUpgrade = enableAnonymousUpgrade;
         this.alwaysShowProviderChoice = alwaysShowProviderChoice;
+        this.emailLink = emailLink;
     }
 
     /**
@@ -102,6 +143,7 @@ public void writeToParcel(Parcel dest, int flags) {
         dest.writeInt(enableHints ? 1 : 0);
         dest.writeInt(enableAnonymousUpgrade ? 1 : 0);
         dest.writeInt(alwaysShowProviderChoice ? 1 : 0);
+        dest.writeString(emailLink);
     }
 
     @Override
@@ -109,39 +151,6 @@ public int describeContents() {
         return 0;
     }
 
-    public static final Creator<FlowParameters> CREATOR = new Creator<FlowParameters>() {
-        @Override
-        public FlowParameters createFromParcel(Parcel in) {
-            String appName = in.readString();
-            List<IdpConfig> providerInfo = in.createTypedArrayList(IdpConfig.CREATOR);
-            int themeId = in.readInt();
-            int logoId = in.readInt();
-            String termsOfServiceUrl = in.readString();
-            String privacyPolicyUrl = in.readString();
-            boolean enableCredentials = in.readInt() != 0;
-            boolean enableHints = in.readInt() != 0;
-            boolean enableAnonymousUpgrade = in.readInt() != 0;
-            boolean alwaysShowProviderChoice = in.readInt() != 0;
-
-            return new FlowParameters(
-                    appName,
-                    providerInfo,
-                    themeId,
-                    logoId,
-                    termsOfServiceUrl,
-                    privacyPolicyUrl,
-                    enableCredentials,
-                    enableHints,
-                    enableAnonymousUpgrade,
-                    alwaysShowProviderChoice);
-        }
-
-        @Override
-        public FlowParameters[] newArray(int size) {
-            return new FlowParameters[size];
-        }
-    };
-
     public boolean isSingleProviderFlow() {
         return providers.size() == 1;
     }
diff --git a/auth/src/main/java/com/firebase/ui/auth/data/remote/SignInKickstarter.java b/auth/src/main/java/com/firebase/ui/auth/data/remote/SignInKickstarter.java
index 5376d1bde..25eb61048 100644
--- a/auth/src/main/java/com/firebase/ui/auth/data/remote/SignInKickstarter.java
+++ b/auth/src/main/java/com/firebase/ui/auth/data/remote/SignInKickstarter.java
@@ -11,12 +11,14 @@
 import com.firebase.ui.auth.AuthUI;
 import com.firebase.ui.auth.ErrorCodes;
 import com.firebase.ui.auth.IdpResponse;
+import com.firebase.ui.auth.util.data.EmailLinkPersistenceManager;
 import com.firebase.ui.auth.data.model.IntentRequiredException;
 import com.firebase.ui.auth.data.model.PendingIntentRequiredException;
 import com.firebase.ui.auth.data.model.Resource;
 import com.firebase.ui.auth.data.model.User;
 import com.firebase.ui.auth.data.model.UserCancellationException;
 import com.firebase.ui.auth.ui.email.EmailActivity;
+import com.firebase.ui.auth.ui.email.EmailLinkCatcherActivity;
 import com.firebase.ui.auth.ui.idp.AuthMethodPickerActivity;
 import com.firebase.ui.auth.ui.idp.SingleSignInActivity;
 import com.firebase.ui.auth.ui.phone.PhoneActivity;
@@ -48,12 +50,21 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import static com.firebase.ui.auth.AuthUI.EMAIL_LINK_PROVIDER;
+
 public class SignInKickstarter extends SignInViewModelBase {
     public SignInKickstarter(Application application) {
         super(application);
     }
 
     public void start() {
+        if (!TextUtils.isEmpty(getArguments().emailLink)) {
+            setResult(Resource.<IdpResponse>forFailure(new IntentRequiredException(
+                    EmailLinkCatcherActivity.createIntent(getApplication(), getArguments()),
+                    RequestCodes.EMAIL_FLOW)));
+            return;
+        }
+
         // Only support password credentials if email auth is enabled
         boolean supportPasswords = ProviderUtils.getConfigFromIdps(
                 getArguments().providers, EmailAuthProvider.PROVIDER_ID) != null;
@@ -100,6 +111,7 @@ private void startAuthMethodChoice() {
             AuthUI.IdpConfig firstIdpConfig = getArguments().providers.get(0);
             String firstProvider = firstIdpConfig.getProviderId();
             switch (firstProvider) {
+                case EMAIL_LINK_PROVIDER:
                 case EmailAuthProvider.PROVIDER_ID:
                     setResult(Resource.<IdpResponse>forFailure(new IntentRequiredException(
                             EmailActivity.createIntent(getApplication(), getArguments()),
@@ -175,10 +187,14 @@ public void onActivityResult(int requestCode, int resultCode, @Nullable Intent d
                     startAuthMethodChoice();
                 }
                 break;
-            case RequestCodes.AUTH_PICKER_FLOW:
             case RequestCodes.EMAIL_FLOW:
+            case RequestCodes.AUTH_PICKER_FLOW:
             case RequestCodes.PHONE_FLOW:
             case RequestCodes.PROVIDER_FLOW:
+                if (resultCode == RequestCodes.EMAIL_LINK_WRONG_DEVICE_FLOW || resultCode == RequestCodes.EMAIL_LINK_INVALID_LINK_FLOW) {
+                    startAuthMethodChoice();
+                    return;
+                }
                 IdpResponse response = IdpResponse.fromResultIntent(data);
                 if (response == null) {
                     setResult(Resource.<IdpResponse>forFailure(new UserCancellationException()));
diff --git a/auth/src/main/java/com/firebase/ui/auth/ui/InvisibleFragmentBase.java b/auth/src/main/java/com/firebase/ui/auth/ui/InvisibleFragmentBase.java
new file mode 100644
index 000000000..8d396ef40
--- /dev/null
+++ b/auth/src/main/java/com/firebase/ui/auth/ui/InvisibleFragmentBase.java
@@ -0,0 +1,91 @@
+package com.firebase.ui.auth.ui;
+
+import android.os.Bundle;
+import android.os.Handler;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.annotation.RestrictTo;
+import android.view.ContextThemeWrapper;
+import android.view.Gravity;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
+
+import com.firebase.ui.auth.R;
+
+import me.zhanghai.android.materialprogressbar.MaterialProgressBar;
+
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+public class InvisibleFragmentBase extends FragmentBase {
+
+    // Minimum time that the spinner will stay on screen, once it is shown.
+    private static final long MIN_SPINNER_MS = 750;
+    protected FrameLayout mFrameLayout;
+    protected View mTopLevelView;
+    private Handler mHandler = new Handler();
+    private MaterialProgressBar mProgressBar;
+    // Last time that the progress bar was actually shown
+    private long mLastShownTime = 0;
+
+    @Override
+    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
+
+        // Create an indeterminate, circular progress bar in the app's theme
+        mProgressBar = new MaterialProgressBar(new ContextThemeWrapper(getContext(),
+                getFlowParams().themeId));
+        mProgressBar.setIndeterminate(true);
+        mProgressBar.setVisibility(View.GONE);
+
+        // Set bar to float in the center
+        FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(
+                ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
+        params.gravity = Gravity.CENTER;
+
+        // Add to the container
+        mFrameLayout = view.findViewById(R.id.invisible_frame);
+        mFrameLayout.addView(mProgressBar, params);
+    }
+
+
+    @Override
+    public void showProgress(int message) {
+        if (mProgressBar.getVisibility() == View.VISIBLE) {
+            mHandler.removeCallbacksAndMessages(null);
+            return;
+        }
+
+        mLastShownTime = System.currentTimeMillis();
+        mProgressBar.setVisibility(View.VISIBLE);
+    }
+
+    @Override
+    public void hideProgress() {
+        doAfterTimeout(new Runnable() {
+            @Override
+            public void run() {
+                mLastShownTime = 0;
+                mProgressBar.setVisibility(View.GONE);
+                mFrameLayout.setVisibility(View.GONE);
+            }
+        });
+    }
+
+    /**
+     * For certain actions (like finishing or hiding the progress dialog) we want to make sure
+     * that we have shown the progress state for at least MIN_SPINNER_MS to prevent flickering.
+     * <p>
+     * This method performs some action after the window has passed, or immediately if we have
+     * already waited longer than that.
+     */
+    protected void doAfterTimeout(Runnable runnable) {
+        long currentTime = System.currentTimeMillis();
+        long diff = currentTime - mLastShownTime;
+
+        // 'diff' is how long it's been since we showed the spinner, so in the
+        // case where diff is greater than our minimum spinner duration then our
+        // remaining wait time is 0.
+        long remaining = Math.max(MIN_SPINNER_MS - diff, 0);
+
+        mHandler.postDelayed(runnable, remaining);
+    }
+}
diff --git a/auth/src/main/java/com/firebase/ui/auth/ui/email/CheckEmailFragment.java b/auth/src/main/java/com/firebase/ui/auth/ui/email/CheckEmailFragment.java
index 220b85b32..7f0718d6c 100644
--- a/auth/src/main/java/com/firebase/ui/auth/ui/email/CheckEmailFragment.java
+++ b/auth/src/main/java/com/firebase/ui/auth/ui/email/CheckEmailFragment.java
@@ -18,6 +18,8 @@
 import android.widget.ProgressBar;
 import android.widget.TextView;
 
+import com.firebase.ui.auth.ErrorCodes;
+import com.firebase.ui.auth.FirebaseUiException;
 import com.firebase.ui.auth.R;
 import com.firebase.ui.auth.data.model.FlowParameters;
 import com.firebase.ui.auth.data.model.User;
@@ -29,6 +31,8 @@
 import com.firebase.ui.auth.viewmodel.ResourceObserver;
 import com.google.firebase.auth.EmailAuthProvider;
 
+import static com.firebase.ui.auth.AuthUI.EMAIL_LINK_PROVIDER;
+
 /**
  * Fragment that shows a form with an email field and checks for existing accounts with that email.
  * <p>
@@ -39,38 +43,12 @@ public class CheckEmailFragment extends FragmentBase implements
         View.OnClickListener,
         ImeHelper.DonePressedListener {
 
-    /**
-     * Interface to be implemented by Activities hosting this Fragment.
-     */
-    interface CheckEmailListener {
-
-        /**
-         * Email entered belongs to an existing email user.
-         */
-        void onExistingEmailUser(User user);
-
-        /**
-         * Email entered belongs to an existing IDP user.
-         */
-        void onExistingIdpUser(User user);
-
-        /**
-         * Email entered does not belong to an existing user.
-         */
-        void onNewUser(User user);
-
-    }
-
     public static final String TAG = "CheckEmailFragment";
-
     private CheckEmailHandler mHandler;
-
     private Button mNextButton;
     private ProgressBar mProgressBar;
-
     private EditText mEmailEditText;
     private TextInputLayout mEmailLayout;
-
     private EmailFieldValidator mEmailFieldValidator;
     private CheckEmailListener mListener;
 
@@ -151,7 +129,8 @@ protected void onSuccess(@NonNull User user) {
                             .setName(user.getName())
                             .setPhotoUri(user.getPhotoUri())
                             .build());
-                } else if (provider.equals(EmailAuthProvider.PROVIDER_ID)) {
+                } else if (provider.equals(EmailAuthProvider.PROVIDER_ID)
+                        || provider.equals(EMAIL_LINK_PROVIDER)) {
                     mListener.onExistingEmailUser(user);
                 } else {
                     mListener.onExistingIdpUser(user);
@@ -160,11 +139,17 @@ protected void onSuccess(@NonNull User user) {
 
             @Override
             protected void onFailure(@NonNull Exception e) {
-                // Just let the user enter their data
+                if (e instanceof FirebaseUiException
+                        && ((FirebaseUiException) e).getErrorCode() == ErrorCodes.DEVELOPER_ERROR) {
+                    mListener.onDeveloperFailure(e);
+                }
+                // Otherwise just let the user enter their data
             }
         });
 
-        if (savedInstanceState != null) { return; }
+        if (savedInstanceState != null) {
+            return;
+        }
 
         // Check for email
         String email = getArguments().getString(ExtraConstants.EMAIL);
@@ -215,4 +200,30 @@ public void hideProgress() {
         mNextButton.setEnabled(true);
         mProgressBar.setVisibility(View.INVISIBLE);
     }
+
+    /**
+     * Interface to be implemented by Activities hosting this Fragment.
+     */
+    interface CheckEmailListener {
+
+        /**
+         * Email entered belongs to an existing email user.
+         */
+        void onExistingEmailUser(User user);
+
+        /**
+         * Email entered belongs to an existing IDP user.
+         */
+        void onExistingIdpUser(User user);
+
+        /**
+         * Email entered does not belong to an existing user.
+         */
+        void onNewUser(User user);
+
+        /**
+         * Email entered corresponds to an existing user whose sign in methods we do not support.
+         */
+        void onDeveloperFailure(Exception e);
+    }
 }
diff --git a/auth/src/main/java/com/firebase/ui/auth/ui/email/EmailActivity.java b/auth/src/main/java/com/firebase/ui/auth/ui/email/EmailActivity.java
index 3704bffcc..5d6a097b6 100644
--- a/auth/src/main/java/com/firebase/ui/auth/ui/email/EmailActivity.java
+++ b/auth/src/main/java/com/firebase/ui/auth/ui/email/EmailActivity.java
@@ -21,11 +21,13 @@
 import android.support.annotation.RestrictTo;
 import android.support.annotation.StringRes;
 import android.support.design.widget.TextInputLayout;
+import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentTransaction;
 import android.support.v4.view.ViewCompat;
 
 import com.firebase.ui.auth.AuthUI;
 import com.firebase.ui.auth.ErrorCodes;
+import com.firebase.ui.auth.FirebaseUiException;
 import com.firebase.ui.auth.IdpResponse;
 import com.firebase.ui.auth.R;
 import com.firebase.ui.auth.data.model.FlowParameters;
@@ -33,10 +35,14 @@
 import com.firebase.ui.auth.ui.AppCompatBase;
 import com.firebase.ui.auth.ui.idp.WelcomeBackIdpPrompt;
 import com.firebase.ui.auth.util.ExtraConstants;
+import com.firebase.ui.auth.util.data.EmailLinkPersistenceManager;
 import com.firebase.ui.auth.util.data.ProviderUtils;
 import com.firebase.ui.auth.viewmodel.RequestCodes;
+import com.google.firebase.auth.ActionCodeSettings;
 import com.google.firebase.auth.EmailAuthProvider;
 
+import static com.firebase.ui.auth.AuthUI.EMAIL_LINK_PROVIDER;
+
 /**
  * Activity to control the entire email sign up flow. Plays host to {@link CheckEmailFragment} and
  * {@link RegisterEmailFragment} and triggers {@link WelcomeBackPasswordPrompt} and {@link
@@ -44,9 +50,11 @@
  */
 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 public class EmailActivity extends AppCompatBase implements CheckEmailFragment.CheckEmailListener,
-        RegisterEmailFragment.AnonymousUpgradeListener {
+        RegisterEmailFragment.AnonymousUpgradeListener, EmailLinkFragment
+                .TroubleSigningInListener, TroubleSigningInFragment.ResendEmailListener {
+
     public static Intent createIntent(Context context, FlowParameters flowParams) {
-        return createIntent(context, flowParams, null);
+        return createBaseIntent(context, EmailActivity.class, flowParams);
     }
 
     public static Intent createIntent(Context context, FlowParameters flowParams, String email) {
@@ -54,6 +62,12 @@ public static Intent createIntent(Context context, FlowParameters flowParams, St
                 .putExtra(ExtraConstants.EMAIL, email);
     }
 
+    public static Intent createIntentForLinking(Context context, FlowParameters flowParams,
+                                                IdpResponse responseForLinking) {
+        return createIntent(context, flowParams, responseForLinking.getEmail())
+                .putExtra(ExtraConstants.IDP_RESPONSE, responseForLinking);
+    }
+
     @Override
     protected void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -66,12 +80,25 @@ protected void onCreate(@Nullable Bundle savedInstanceState) {
         // Get email from intent (can be null)
         String email = getIntent().getExtras().getString(ExtraConstants.EMAIL);
 
-        // Start with check email
-        CheckEmailFragment fragment = CheckEmailFragment.newInstance(email);
-        getSupportFragmentManager().beginTransaction()
-                .replace(R.id.fragment_register_email, fragment, CheckEmailFragment.TAG)
-                .disallowAddToBackStack()
-                .commit();
+        IdpResponse responseForLinking = getIntent().getExtras().getParcelable(ExtraConstants
+                .IDP_RESPONSE);
+        if (email != null && responseForLinking != null) {
+            // got here from WelcomeBackEmailLinkPrompt
+            AuthUI.IdpConfig emailConfig = ProviderUtils.getConfigFromIdpsOrThrow(
+                    getFlowParams().providers, EMAIL_LINK_PROVIDER);
+            ActionCodeSettings actionCodeSettings = emailConfig.getParams().getParcelable
+                    (ExtraConstants.ACTION_CODE_SETTINGS);
+
+            EmailLinkPersistenceManager.getInstance().saveIdpResponseForLinking(getApplication(),
+                    responseForLinking);
+
+            EmailLinkFragment fragment = EmailLinkFragment.newInstance(email, actionCodeSettings);
+            switchFragment(fragment, EmailLinkFragment.TAG);
+        } else {
+            // Start with check email
+            CheckEmailFragment fragment = CheckEmailFragment.newInstance(email);
+            switchFragment(fragment, CheckEmailFragment.TAG);
+        }
     }
 
     @Override
@@ -85,17 +112,23 @@ protected void onActivityResult(int requestCode, int resultCode, Intent data) {
 
     @Override
     public void onExistingEmailUser(User user) {
-        // Existing email user, direct them to sign in with their password.
-        startActivityForResult(
-                WelcomeBackPasswordPrompt.createIntent(
-                        this, getFlowParams(), new IdpResponse.Builder(user).build()),
-                RequestCodes.WELCOME_BACK_EMAIL_FLOW);
-
-        setSlideAnimation();
+        if (user.getProviderId().equals(EMAIL_LINK_PROVIDER)) {
+            AuthUI.IdpConfig emailConfig = ProviderUtils.getConfigFromIdpsOrThrow(
+                    getFlowParams().providers, EMAIL_LINK_PROVIDER);
+            showRegisterEmailLinkFragment(
+                    emailConfig, user.getEmail());
+        } else {
+            startActivityForResult(
+                    WelcomeBackPasswordPrompt.createIntent(
+                            this, getFlowParams(), new IdpResponse.Builder(user).build()),
+                    RequestCodes.WELCOME_BACK_EMAIL_FLOW);
+            setSlideAnimation();
+        }
     }
 
     @Override
     public void onExistingIdpUser(User user) {
+
         // Existing social user, direct them to sign in using their chosen provider.
         startActivityForResult(
                 WelcomeBackIdpPrompt.createIntent(this, getFlowParams(), user),
@@ -109,31 +142,90 @@ public void onNewUser(User user) {
         // if account creation is enabled in SignInIntentBuilder
 
         TextInputLayout emailLayout = findViewById(R.id.email_layout);
+        AuthUI.IdpConfig emailConfig = ProviderUtils.getConfigFromIdps(getFlowParams().providers,
+                EmailAuthProvider.PROVIDER_ID);
+
+        if (emailConfig == null) {
+            emailConfig = ProviderUtils.getConfigFromIdps(getFlowParams().providers,
+                    EMAIL_LINK_PROVIDER);
+        }
 
-        AuthUI.IdpConfig emailConfig = ProviderUtils.getConfigFromIdpsOrThrow(
-                getFlowParams().providers, EmailAuthProvider.PROVIDER_ID);
         if (emailConfig.getParams().getBoolean(ExtraConstants.ALLOW_NEW_EMAILS, true)) {
-            RegisterEmailFragment fragment = RegisterEmailFragment.newInstance(user);
-            FragmentTransaction ft = getSupportFragmentManager().beginTransaction()
-                    .replace(R.id.fragment_register_email, fragment, RegisterEmailFragment.TAG);
-
-            if (emailLayout != null) {
-                String emailFieldName = getString(R.string.fui_email_field_name);
-                ViewCompat.setTransitionName(emailLayout, emailFieldName);
-                ft.addSharedElement(emailLayout, emailFieldName);
+            FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
+            if (emailConfig.getProviderId().equals(EMAIL_LINK_PROVIDER)) {
+                showRegisterEmailLinkFragment(emailConfig, user.getEmail());
+            } else {
+                RegisterEmailFragment fragment = RegisterEmailFragment.newInstance(user);
+                ft.replace(R.id.fragment_register_email, fragment, RegisterEmailFragment.TAG);
+                if (emailLayout != null) {
+                    String emailFieldName = getString(R.string.fui_email_field_name);
+                    ViewCompat.setTransitionName(emailLayout, emailFieldName);
+                    ft.addSharedElement(emailLayout, emailFieldName);
+                }
+                ft.disallowAddToBackStack().commit();
             }
-
-            ft.disallowAddToBackStack().commit();
         } else {
             emailLayout.setError(getString(R.string.fui_error_email_does_not_exist));
         }
     }
 
+    @Override
+    public void onTroubleSigningIn(String email) {
+        TroubleSigningInFragment troubleSigningInFragment = TroubleSigningInFragment.newInstance
+                (email);
+        switchFragment(troubleSigningInFragment, TroubleSigningInFragment.TAG, true);
+    }
+
+    @Override
+    public void onClickResendEmail(String email) {
+        AuthUI.IdpConfig emailConfig = ProviderUtils.getConfigFromIdpsOrThrow(
+                getFlowParams().providers, EmailAuthProvider.EMAIL_LINK_SIGN_IN_METHOD);
+        showRegisterEmailLinkFragment(
+                emailConfig, email);
+    }
+
+    @Override
+    public void onSendEmailFailure(Exception e) {
+        finishOnDeveloperError(e);
+    }
+
+    @Override
+    public void onDeveloperFailure(Exception e) {
+        finishOnDeveloperError(e);
+    }
+
+    private void finishOnDeveloperError(Exception e) {
+        finish(RESULT_CANCELED, IdpResponse.getErrorIntent(new FirebaseUiException(
+                ErrorCodes.DEVELOPER_ERROR, e.getMessage())));
+    }
+
     private void setSlideAnimation() {
         // Make the next activity slide in
         overridePendingTransition(R.anim.fui_slide_in_right, R.anim.fui_slide_out_left);
     }
 
+    private void showRegisterEmailLinkFragment(AuthUI.IdpConfig emailConfig,
+                                               String email) {
+        ActionCodeSettings actionCodeSettings = emailConfig.getParams().getParcelable
+                (ExtraConstants.ACTION_CODE_SETTINGS);
+        EmailLinkFragment fragment = EmailLinkFragment.newInstance(email,
+                actionCodeSettings);
+        switchFragment(fragment, EmailLinkFragment.TAG);
+    }
+
+
+    private void switchFragment(Fragment fragment, String tag, boolean withTransition) {
+        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
+        if (withTransition) {
+            ft.setCustomAnimations(R.anim.fui_slide_in_right, R.anim.fui_slide_out_left);
+        }
+        ft.replace(R.id.fragment_register_email, fragment, tag).disallowAddToBackStack().commit();
+    }
+
+    private void switchFragment(Fragment fragment, String tag) {
+        switchFragment(fragment, tag, false);
+    }
+
     @Override
     public void showProgress(@StringRes int message) {
         throw new UnsupportedOperationException("Email fragments must handle progress updates.");
diff --git a/auth/src/main/java/com/firebase/ui/auth/ui/email/EmailLinkCatcherActivity.java b/auth/src/main/java/com/firebase/ui/auth/ui/email/EmailLinkCatcherActivity.java
new file mode 100644
index 000000000..b1e14a956
--- /dev/null
+++ b/auth/src/main/java/com/firebase/ui/auth/ui/email/EmailLinkCatcherActivity.java
@@ -0,0 +1,102 @@
+package com.firebase.ui.auth.ui.email;
+
+import android.app.AlertDialog;
+import android.arch.lifecycle.ViewModelProviders;
+import android.content.Context;
+import android.content.DialogInterface;
+import android.content.Intent;
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.annotation.RestrictTo;
+
+import com.firebase.ui.auth.ErrorCodes;
+import com.firebase.ui.auth.FirebaseAuthAnonymousUpgradeException;
+import com.firebase.ui.auth.FirebaseUiException;
+import com.firebase.ui.auth.IdpResponse;
+import com.firebase.ui.auth.R;
+import com.firebase.ui.auth.data.model.FlowParameters;
+import com.firebase.ui.auth.data.model.UserCancellationException;
+import com.firebase.ui.auth.ui.InvisibleActivityBase;
+import com.firebase.ui.auth.util.ExtraConstants;
+import com.firebase.ui.auth.viewmodel.RequestCodes;
+import com.firebase.ui.auth.viewmodel.ResourceObserver;
+import com.firebase.ui.auth.viewmodel.email.EmailLinkSignInHandler;
+
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+public class EmailLinkCatcherActivity extends InvisibleActivityBase {
+
+    private EmailLinkSignInHandler mHandler;
+
+    public static Intent createIntent(Context context, FlowParameters flowParams) {
+        return createBaseIntent(context, EmailLinkCatcherActivity.class, flowParams);
+    }
+
+    @Override
+    protected void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        initHandler();
+
+        if (getFlowParams().emailLink != null) {
+            mHandler.startSignIn();
+        }
+    }
+
+    private void initHandler() {
+        mHandler = ViewModelProviders.of(this).get(EmailLinkSignInHandler.class);
+        mHandler.init(getFlowParams());
+        mHandler.getOperation().observe(this, new ResourceObserver<IdpResponse>(this) {
+            @Override
+            protected void onSuccess(@NonNull IdpResponse response) {
+                finish(RESULT_OK, response.toIntent());
+            }
+
+            @Override
+            protected void onFailure(@NonNull final Exception e) {
+                if (e instanceof UserCancellationException) {
+                    finish(RESULT_CANCELED, null);
+                } else if (e instanceof FirebaseAuthAnonymousUpgradeException) {
+                    IdpResponse res = ((FirebaseAuthAnonymousUpgradeException) e).getResponse();
+                    finish(RESULT_CANCELED, new Intent().putExtra(ExtraConstants
+                            .IDP_RESPONSE, res));
+                } else {
+                    if (e instanceof FirebaseUiException) {
+                        if (((FirebaseUiException) e).getErrorCode() == ErrorCodes
+                                .EMAIL_LINK_WRONG_DEVICE_ERROR) {
+                            buildAlertDialog(ErrorCodes.EMAIL_LINK_WRONG_DEVICE_ERROR).show();
+                        } else if (((FirebaseUiException) e).getErrorCode() == ErrorCodes
+                                .INVALID_EMAIL_LINK_ERROR) {
+                            buildAlertDialog(ErrorCodes.INVALID_EMAIL_LINK_ERROR).show();
+                        }
+                    } else {
+                        finish(RESULT_CANCELED, IdpResponse.getErrorIntent(e));
+                    }
+                }
+            }
+        });
+    }
+
+    private AlertDialog buildAlertDialog(int errorCode) {
+        AlertDialog.Builder alertDialog = new AlertDialog.Builder(this);
+        if (errorCode == ErrorCodes.EMAIL_LINK_WRONG_DEVICE_ERROR) {
+            alertDialog.setTitle(R.string.fui_email_link_wrong_device_header)
+                    .setMessage(R.string.fui_email_link_wrong_device_message)
+                    .setPositiveButton(R.string.fui_email_link_dismiss_button,
+                            new DialogInterface.OnClickListener() {
+                                public void onClick(DialogInterface dialog, int id) {
+                                    finish(RequestCodes.EMAIL_LINK_WRONG_DEVICE_FLOW, null);
+                                }
+                            });
+        } else if (errorCode == ErrorCodes.INVALID_EMAIL_LINK_ERROR) {
+            alertDialog.setTitle(R.string.fui_email_link_invalid_link_header)
+                    .setMessage(R.string.fui_email_link_invalid_link_message)
+                    .setPositiveButton(R.string.fui_email_link_dismiss_button,
+                            new DialogInterface.OnClickListener() {
+                                public void onClick(DialogInterface dialog, int id) {
+                                    finish(RequestCodes.EMAIL_LINK_INVALID_LINK_FLOW, null);
+                                }
+                            });
+        }
+        return alertDialog.create();
+    }
+}
diff --git a/auth/src/main/java/com/firebase/ui/auth/ui/email/EmailLinkFragment.java b/auth/src/main/java/com/firebase/ui/auth/ui/email/EmailLinkFragment.java
new file mode 100644
index 000000000..c4fd0cc93
--- /dev/null
+++ b/auth/src/main/java/com/firebase/ui/auth/ui/email/EmailLinkFragment.java
@@ -0,0 +1,159 @@
+package com.firebase.ui.auth.ui.email;
+
+import android.arch.lifecycle.ViewModelProviders;
+import android.content.Context;
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.annotation.RestrictTo;
+import android.support.v4.app.FragmentActivity;
+import android.text.SpannableStringBuilder;
+import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ScrollView;
+import android.widget.TextView;
+
+import com.firebase.ui.auth.R;
+import com.firebase.ui.auth.ui.InvisibleFragmentBase;
+import com.firebase.ui.auth.util.ExtraConstants;
+import com.firebase.ui.auth.util.data.PrivacyDisclosureUtils;
+import com.firebase.ui.auth.util.ui.TextHelper;
+import com.firebase.ui.auth.viewmodel.ResourceObserver;
+import com.firebase.ui.auth.viewmodel.email.EmailLinkSendEmailHandler;
+import com.google.firebase.auth.ActionCodeSettings;
+
+
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+public class EmailLinkFragment extends InvisibleFragmentBase {
+
+    public static final String TAG = "EmailLinkFragment";
+    private static final String EMAIL_SENT = "emailSent";
+    private EmailLinkSendEmailHandler mEmailLinkSendEmailHandler;
+    private TroubleSigningInListener mListener;
+    private ScrollView mTopLevelView;
+
+    public static EmailLinkFragment newInstance(@NonNull final String email,
+                                                @NonNull final ActionCodeSettings
+                                                        actionCodeSettings) {
+        EmailLinkFragment fragment = new EmailLinkFragment();
+        Bundle args = new Bundle();
+        args.putString(ExtraConstants.EMAIL, email);
+        args.putParcelable(ExtraConstants.ACTION_CODE_SETTINGS, actionCodeSettings);
+        fragment.setArguments(args);
+        return fragment;
+    }
+
+    @Override
+    public void onAttach(Context context) {
+        super.onAttach(context);
+        FragmentActivity activity = getActivity();
+        if (!(activity instanceof TroubleSigningInListener)) {
+            throw new IllegalStateException("Activity must implement TroubleSigningInListener");
+        }
+        mListener = (TroubleSigningInListener) activity;
+    }
+
+    @Override
+    public View onCreateView(@NonNull LayoutInflater inflater,
+                             @Nullable ViewGroup container,
+                             @Nullable Bundle savedInstanceState) {
+        return inflater.inflate(R.layout.fui_email_link_sign_in_layout, container, false);
+    }
+
+    @Override
+    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
+        super.onViewCreated(view, savedInstanceState);
+        // We need to hide the top level view until we know that the email link has been sent
+        mTopLevelView = view.findViewById(R.id.top_level_view);
+        mTopLevelView.setVisibility(View.GONE);
+
+        String email = getArguments().getString(ExtraConstants.EMAIL);
+        setBodyText(view, email);
+        setOnClickListeners(view, email);
+        setPrivacyFooter(view);
+
+    }
+
+    @Override
+    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
+        super.onActivityCreated(savedInstanceState);
+        initHandler();
+
+        String email = getArguments().getString(ExtraConstants.EMAIL);
+        ActionCodeSettings actionCodeSettings = getArguments().getParcelable(ExtraConstants
+                .ACTION_CODE_SETTINGS);
+
+        if (savedInstanceState == null || !savedInstanceState.getBoolean(EMAIL_SENT)) {
+            mEmailLinkSendEmailHandler.sendSignInLinkToEmail(email, actionCodeSettings);
+        }
+    }
+
+    private void initHandler() {
+        mEmailLinkSendEmailHandler = ViewModelProviders.of(this).get(EmailLinkSendEmailHandler
+                .class);
+        mEmailLinkSendEmailHandler.init(getFlowParams());
+
+        mEmailLinkSendEmailHandler.getOperation().observe(this, new ResourceObserver<String>(this,
+                R.string.fui_progress_dialog_sending) {
+            @Override
+            protected void onSuccess(@NonNull String email) {
+                Log.w(TAG, "Email for email link sign in sent successfully.");
+                doAfterTimeout(new Runnable() {
+                    @Override
+                    public void run() {
+                        mTopLevelView.setVisibility(View.VISIBLE);
+                    }
+                });
+            }
+
+            @Override
+            protected void onFailure(@NonNull Exception e) {
+                mListener.onSendEmailFailure(e);
+            }
+        });
+    }
+
+    private void setBodyText(View view, final String email) {
+        TextView body = view.findViewById(R.id.sign_in_email_sent_text);
+        String bodyText = getString(R.string.fui_email_link_email_sent, email);
+
+        SpannableStringBuilder spannableStringBuilder = new SpannableStringBuilder(bodyText);
+        TextHelper.boldAllOccurencesOfText(spannableStringBuilder, bodyText, email);
+        body.setText(spannableStringBuilder);
+    }
+
+    private void setOnClickListeners(View view, final String email) {
+        view.findViewById(R.id.trouble_signing_in).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                mListener.onTroubleSigningIn(email);
+            }
+        });
+    }
+
+    private void setPrivacyFooter(View view) {
+        TextView footerText = view.findViewById(R.id.email_footer_tos_and_pp_text);
+        PrivacyDisclosureUtils.setupTermsOfServiceFooter(requireContext(), getFlowParams(),
+                footerText);
+    }
+
+    @Override
+    public void onSaveInstanceState(Bundle state) {
+        super.onSaveInstanceState(state);
+        state.putBoolean(EMAIL_SENT, true);
+    }
+
+    interface TroubleSigningInListener {
+        /**
+         * User clicks on trouble signing in.
+         */
+        void onTroubleSigningIn(String email);
+
+        /**
+         * Failure occurs when trying to send the email.
+         */
+        void onSendEmailFailure(Exception e);
+    }
+}
diff --git a/auth/src/main/java/com/firebase/ui/auth/ui/email/RegisterEmailFragment.java b/auth/src/main/java/com/firebase/ui/auth/ui/email/RegisterEmailFragment.java
index b7ad7ccdb..dbf0579f9 100644
--- a/auth/src/main/java/com/firebase/ui/auth/ui/email/RegisterEmailFragment.java
+++ b/auth/src/main/java/com/firebase/ui/auth/ui/email/RegisterEmailFragment.java
@@ -221,7 +221,6 @@ public void onActivityCreated(@Nullable Bundle savedInstanceState) {
             throw new IllegalStateException("Activity must implement CheckEmailListener");
         }
         mListener = (AnonymousUpgradeListener) activity;
-
     }
 
     @Override
diff --git a/auth/src/main/java/com/firebase/ui/auth/ui/email/TroubleSigningInFragment.java b/auth/src/main/java/com/firebase/ui/auth/ui/email/TroubleSigningInFragment.java
new file mode 100644
index 000000000..72ea4ff01
--- /dev/null
+++ b/auth/src/main/java/com/firebase/ui/auth/ui/email/TroubleSigningInFragment.java
@@ -0,0 +1,98 @@
+package com.firebase.ui.auth.ui.email;
+
+import android.content.Context;
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.annotation.RestrictTo;
+import android.support.v4.app.FragmentActivity;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ProgressBar;
+import android.widget.TextView;
+
+import com.firebase.ui.auth.R;
+import com.firebase.ui.auth.ui.FragmentBase;
+import com.firebase.ui.auth.util.ExtraConstants;
+import com.firebase.ui.auth.util.data.PrivacyDisclosureUtils;
+
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+public class TroubleSigningInFragment extends FragmentBase implements View.OnClickListener {
+
+    public static final String TAG = "TroubleSigningInFragment";
+
+    private ResendEmailListener mListener;
+    private ProgressBar mProgressBar;
+
+    private String mEmail;
+
+    public static TroubleSigningInFragment newInstance(@NonNull final String email) {
+        TroubleSigningInFragment fragment = new TroubleSigningInFragment();
+        Bundle args = new Bundle();
+        args.putString(ExtraConstants.EMAIL, email);
+        fragment.setArguments(args);
+        return fragment;
+    }
+
+    @Override
+    public View onCreateView(@NonNull LayoutInflater inflater,
+                             @Nullable ViewGroup container,
+                             @Nullable Bundle savedInstanceState) {
+        return inflater.inflate(R.layout.fui_email_link_trouble_signing_in_layout, container,
+                false);
+    }
+
+    @Override
+    public void onAttach(Context context) {
+        super.onAttach(context);
+        FragmentActivity activity = getActivity();
+        if (!(activity instanceof ResendEmailListener)) {
+            throw new IllegalStateException("Activity must implement ResendEmailListener");
+        }
+        mListener = (ResendEmailListener) activity;
+    }
+
+    @Override
+    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
+        mProgressBar = view.findViewById(R.id.top_progress_bar);
+        mEmail = getArguments().getString(ExtraConstants.EMAIL);
+
+        setOnClickListeners(view);
+        setPrivacyFooter(view);
+    }
+
+    private void setOnClickListeners(View view) {
+        view.findViewById(R.id.button_resend_email).setOnClickListener(this);
+    }
+
+    private void setPrivacyFooter(View view) {
+        TextView footerText = view.findViewById(R.id.email_footer_tos_and_pp_text);
+        PrivacyDisclosureUtils.setupTermsOfServiceFooter(requireContext(), getFlowParams(),
+                footerText);
+    }
+
+    @Override
+    public void onClick(View view) {
+        if (view.getId() == R.id.button_resend_email) {
+            mListener.onClickResendEmail(mEmail);
+        }
+    }
+
+    @Override
+    public void showProgress(int message) {
+        mProgressBar.setVisibility(View.VISIBLE);
+    }
+
+    @Override
+    public void hideProgress() {
+        mProgressBar.setVisibility(View.INVISIBLE);
+    }
+
+    interface ResendEmailListener {
+        /**
+         * User clicks on the resend email button.
+         */
+        void onClickResendEmail(String email);
+    }
+}
diff --git a/auth/src/main/java/com/firebase/ui/auth/ui/email/WelcomeBackEmailLinkPrompt.java b/auth/src/main/java/com/firebase/ui/auth/ui/email/WelcomeBackEmailLinkPrompt.java
new file mode 100644
index 000000000..62d95768d
--- /dev/null
+++ b/auth/src/main/java/com/firebase/ui/auth/ui/email/WelcomeBackEmailLinkPrompt.java
@@ -0,0 +1,117 @@
+package com.firebase.ui.auth.ui.email;
+
+import android.content.Context;
+import android.content.Intent;
+import android.os.Build;
+import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.support.annotation.RestrictTo;
+import android.text.SpannableStringBuilder;
+import android.view.View;
+import android.widget.Button;
+import android.widget.ProgressBar;
+import android.widget.TextView;
+
+import com.firebase.ui.auth.IdpResponse;
+import com.firebase.ui.auth.R;
+import com.firebase.ui.auth.data.model.FlowParameters;
+import com.firebase.ui.auth.ui.AppCompatBase;
+import com.firebase.ui.auth.util.ExtraConstants;
+import com.firebase.ui.auth.util.data.PrivacyDisclosureUtils;
+import com.firebase.ui.auth.util.ui.TextHelper;
+import com.firebase.ui.auth.viewmodel.RequestCodes;
+
+import static android.text.Layout.JUSTIFICATION_MODE_INTER_WORD;
+
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+public class WelcomeBackEmailLinkPrompt extends AppCompatBase implements View.OnClickListener {
+
+
+    private IdpResponse mIdpResponseForLinking;
+    private Button mSignInButton;
+    private ProgressBar mProgressBar;
+
+
+    public static Intent createIntent(
+            Context context, FlowParameters flowParams, IdpResponse response) {
+        return createBaseIntent(context, WelcomeBackEmailLinkPrompt.class, flowParams)
+                .putExtra(ExtraConstants.IDP_RESPONSE, response);
+    }
+
+    @Override
+    protected void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.fui_welcome_back_email_link_prompt_layout);
+        mIdpResponseForLinking = IdpResponse.fromResultIntent(getIntent());
+        initializeViewObjects();
+        setBodyText();
+        setOnClickListeners();
+        setPrivacyFooter();
+    }
+
+    private void startEmailLinkFlow() {
+        Intent intent = EmailActivity.createIntentForLinking(this, getFlowParams(),
+                mIdpResponseForLinking);
+        startActivityForResult(intent, RequestCodes.WELCOME_BACK_EMAIL_LINK_FLOW);
+    }
+
+    @Override
+    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+        super.onActivityResult(requestCode, resultCode, data);
+        finish(resultCode, data);
+    }
+
+    private void initializeViewObjects() {
+        mSignInButton = findViewById(R.id.button_sign_in);
+        mProgressBar = findViewById(R.id.top_progress_bar);
+    }
+
+    private void setBodyText() {
+        TextView body = findViewById(R.id.welcome_back_email_link_body);
+        String bodyText = getString(R.string.fui_welcome_back_email_link_prompt_body,
+                mIdpResponseForLinking.getEmail(),
+                mIdpResponseForLinking
+                        .getProviderType());
+
+        SpannableStringBuilder spannableStringBuilder = new SpannableStringBuilder(bodyText);
+        // bold email & provider text
+        TextHelper.boldAllOccurencesOfText(spannableStringBuilder, bodyText,
+                mIdpResponseForLinking.getEmail());
+        TextHelper.boldAllOccurencesOfText(spannableStringBuilder, bodyText,
+                mIdpResponseForLinking.getProviderType());
+
+        body.setText(spannableStringBuilder);
+        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            body.setJustificationMode(JUSTIFICATION_MODE_INTER_WORD);
+        }
+    }
+
+    private void setOnClickListeners() {
+        mSignInButton.setOnClickListener(this);
+    }
+
+    private void setPrivacyFooter() {
+        TextView footerText = findViewById(R.id.email_footer_tos_and_pp_text);
+        PrivacyDisclosureUtils.setupTermsOfServiceFooter(this, getFlowParams(), footerText);
+    }
+
+    @Override
+    public void onClick(View view) {
+        final int id = view.getId();
+        if (id == R.id.button_sign_in) {
+            startEmailLinkFlow();
+        }
+    }
+
+    @Override
+    public void showProgress(int message) {
+        mSignInButton.setEnabled(false);
+        mProgressBar.setVisibility(View.VISIBLE);
+    }
+
+    @Override
+    public void hideProgress() {
+        mProgressBar.setEnabled(true);
+        mProgressBar.setVisibility(View.INVISIBLE);
+    }
+}
diff --git a/auth/src/main/java/com/firebase/ui/auth/ui/email/WelcomeBackPasswordPrompt.java b/auth/src/main/java/com/firebase/ui/auth/ui/email/WelcomeBackPasswordPrompt.java
index 45218c32d..87edcc440 100644
--- a/auth/src/main/java/com/firebase/ui/auth/ui/email/WelcomeBackPasswordPrompt.java
+++ b/auth/src/main/java/com/firebase/ui/auth/ui/email/WelcomeBackPasswordPrompt.java
@@ -45,6 +45,7 @@
 import com.firebase.ui.auth.util.data.PrivacyDisclosureUtils;
 import com.firebase.ui.auth.util.data.ProviderUtils;
 import com.firebase.ui.auth.util.ui.ImeHelper;
+import com.firebase.ui.auth.util.ui.TextHelper;
 import com.firebase.ui.auth.viewmodel.ResourceObserver;
 import com.firebase.ui.auth.viewmodel.email.WelcomeBackPasswordHandler;
 import com.google.firebase.auth.AuthCredential;
@@ -94,11 +95,7 @@ protected void onCreate(@Nullable Bundle savedInstanceState) {
                 getString(R.string.fui_welcome_back_password_prompt_body, email);
 
         SpannableStringBuilder spannableStringBuilder = new SpannableStringBuilder(bodyText);
-        int emailStart = bodyText.indexOf(email);
-        spannableStringBuilder.setSpan(new StyleSpan(Typeface.BOLD),
-                emailStart,
-                emailStart + email.length(),
-                Spannable.SPAN_INCLUSIVE_INCLUSIVE);
+        TextHelper.boldAllOccurencesOfText(spannableStringBuilder, bodyText, email);
 
         TextView bodyTextView = findViewById(R.id.welcome_back_password_body);
         bodyTextView.setText(spannableStringBuilder);
diff --git a/auth/src/main/java/com/firebase/ui/auth/ui/idp/AuthMethodPickerActivity.java b/auth/src/main/java/com/firebase/ui/auth/ui/idp/AuthMethodPickerActivity.java
index 1bc7d4444..a0c93a6e6 100644
--- a/auth/src/main/java/com/firebase/ui/auth/ui/idp/AuthMethodPickerActivity.java
+++ b/auth/src/main/java/com/firebase/ui/auth/ui/idp/AuthMethodPickerActivity.java
@@ -63,7 +63,11 @@
 import java.util.ArrayList;
 import java.util.List;
 
-/** Presents the list of authentication options for this app to the user. */
+import static com.firebase.ui.auth.AuthUI.EMAIL_LINK_PROVIDER;
+
+/**
+ * Presents the list of authentication options for this app to the user.
+ */
 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 public class AuthMethodPickerActivity extends AppCompatBase {
 
@@ -89,7 +93,7 @@ protected void onCreate(@Nullable Bundle savedInstanceState) {
         mHandler = ViewModelProviders.of(this).get(SocialProviderResponseHandler.class);
         mHandler.init(params);
 
-        populateIdpList(params.providers, mHandler);
+        populateIdpList(params.providers);
 
         int logoId = params.logoId;
         if (logoId == AuthUI.NO_LOGO) {
@@ -140,8 +144,7 @@ protected void onFailure(@NonNull Exception e) {
         }
     }
 
-    private void populateIdpList(List<IdpConfig> providerConfigs,
-                                 final SocialProviderResponseHandler handler) {
+    private void populateIdpList(List<IdpConfig> providerConfigs) {
         ViewModelProvider supplier = ViewModelProviders.of(this);
 
         mProviders = new ArrayList<>();
@@ -180,6 +183,7 @@ private void populateIdpList(List<IdpConfig> providerConfigs,
 
                     buttonLayout = R.layout.fui_idp_button_github;
                     break;
+                case EMAIL_LINK_PROVIDER:
                 case EmailAuthProvider.PROVIDER_ID:
                     EmailSignInHandler email = supplier.get(EmailSignInHandler.class);
                     email.init(null);
@@ -221,14 +225,14 @@ private void handleResponse(@NonNull IdpResponse response) {
                     if (!response.isSuccessful()) {
                         // We have no idea what provider this error stemmed from so just forward
                         // this along to the handler.
-                        handler.startSignIn(response);
+                        mHandler.startSignIn(response);
                     } else if (AuthUI.SOCIAL_PROVIDERS.contains(providerId)) {
                         // Don't use the response's provider since it can be different than the one
                         // that launched the sign-in attempt. Ex: the email flow is started, but
                         // ends up turning into a Google sign-in because that account already
                         // existed. In the previous example, an extra sign-in would incorrectly
                         // started.
-                        handler.startSignIn(response);
+                        mHandler.startSignIn(response);
                     } else {
                         // Email or phone: the credentials should have already been saved so
                         // simply move along. Anononymous sign in also does not require any
diff --git a/auth/src/main/java/com/firebase/ui/auth/util/ExtraConstants.java b/auth/src/main/java/com/firebase/ui/auth/util/ExtraConstants.java
index 96e5a6627..5cd65f637 100644
--- a/auth/src/main/java/com/firebase/ui/auth/util/ExtraConstants.java
+++ b/auth/src/main/java/com/firebase/ui/auth/util/ExtraConstants.java
@@ -42,6 +42,9 @@ public final class ExtraConstants {
     public static final String WHITELISTED_COUNTRIES = "whitelisted_countries";
     public static final String BLACKLISTED_COUNTRIES = "blacklisted_countries";
 
+    public static final String EMAIL_LINK_SIGN_IN = "email_link_sign_in";
+    public static final String ACTION_CODE_SETTINGS = "action_code_settings";
+
     private ExtraConstants() {
         throw new AssertionError("No instance for you!");
     }
diff --git a/auth/src/main/java/com/firebase/ui/auth/util/data/EmailLinkParser.java b/auth/src/main/java/com/firebase/ui/auth/util/data/EmailLinkParser.java
new file mode 100644
index 000000000..f8a824495
--- /dev/null
+++ b/auth/src/main/java/com/firebase/ui/auth/util/data/EmailLinkParser.java
@@ -0,0 +1,37 @@
+package com.firebase.ui.auth.util.data;
+
+import android.net.Uri;
+import android.support.annotation.RestrictTo;
+
+import java.util.Set;
+
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+public class EmailLinkParser {
+
+    private static String LINK = "link";
+    private static final String OOB_CODE = "oobCode";
+
+    private static EmailLinkParser instance = new EmailLinkParser();
+
+    private EmailLinkParser() {}
+
+    public static EmailLinkParser getInstance() {
+        return instance;
+    }
+
+    public String getOobCodeFromLink(String signInLink) {
+        Uri uri = Uri.parse(signInLink);
+        try {
+            Set<String> params = uri.getQueryParameterNames();
+            if (params.contains(OOB_CODE)) {
+                return uri.getQueryParameter(OOB_CODE);
+            } else if (params.contains(LINK)) {
+                Uri innerUri = Uri.parse(uri.getQueryParameter(LINK));
+                return innerUri.getQueryParameter(OOB_CODE);
+            }
+        } catch (UnsupportedOperationException e) {
+
+        }
+        return null;
+    }
+}
diff --git a/auth/src/main/java/com/firebase/ui/auth/util/data/EmailLinkPersistenceManager.java b/auth/src/main/java/com/firebase/ui/auth/util/data/EmailLinkPersistenceManager.java
new file mode 100644
index 000000000..0002dc772
--- /dev/null
+++ b/auth/src/main/java/com/firebase/ui/auth/util/data/EmailLinkPersistenceManager.java
@@ -0,0 +1,107 @@
+package com.firebase.ui.auth.util.data;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.annotation.RestrictTo;
+
+import com.firebase.ui.auth.IdpResponse;
+import com.firebase.ui.auth.data.model.User;
+import com.google.android.gms.common.internal.Preconditions;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+
+/**
+ * Manages saving/reading from SharedPreferences for email link sign in.
+ */
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+public class EmailLinkPersistenceManager {
+
+    private static final String SHARED_PREF_NAME =
+            "com.firebase.ui.auth.util.data.EmailLinkPersistenceManager";
+
+    private static final String KEY_EMAIL = "com.firebase.ui.auth.data.client.email";
+    private static final String KEY_PROVIDER = "com.firebase.ui.auth.data.client.provider";
+    private static final String KEY_IDP_TOKEN = "com.firebase.ui.auth.data.client.idpToken";
+    private static final String KEY_IDP_SECRET = "com.firebase.ui.auth.data.client.idpSecret";
+
+
+    private static final Set<String> KEYS =
+            Collections.unmodifiableSet(new HashSet<>(Arrays.asList(KEY_EMAIL, KEY_PROVIDER,
+                    KEY_IDP_TOKEN, KEY_IDP_SECRET)));
+
+
+    private static final EmailLinkPersistenceManager instance = new EmailLinkPersistenceManager();
+
+    public static EmailLinkPersistenceManager getInstance() {
+        return instance;
+    }
+
+    public void saveEmailForLink(@NonNull Context context, @NonNull String email) {
+        Preconditions.checkNotNull(context);
+        Preconditions.checkNotNull(email);
+        SharedPreferences.Editor editor =
+                context.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE).edit();
+        editor.putString(KEY_EMAIL, email);
+        editor.apply();
+    }
+
+    public void saveIdpResponseForLinking(@NonNull Context context, @NonNull IdpResponse
+            idpResponseForLinking) {
+        Preconditions.checkNotNull(context);
+        Preconditions.checkNotNull(idpResponseForLinking);
+        SharedPreferences.Editor editor =
+                context.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE).edit();
+        editor.putString(KEY_EMAIL, idpResponseForLinking.getEmail());
+        editor.putString(KEY_PROVIDER, idpResponseForLinking.getProviderType());
+        editor.putString(KEY_IDP_TOKEN, idpResponseForLinking.getIdpToken());
+        editor.putString(KEY_IDP_SECRET, idpResponseForLinking.getIdpSecret());
+        editor.apply();
+    }
+
+    @Nullable
+    public String retrieveEmailForLink(@NonNull Context context) {
+        Preconditions.checkNotNull(context);
+        SharedPreferences sharedPreferences =
+                context.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
+        return sharedPreferences.getString(KEY_EMAIL, null);
+
+    }
+
+    public IdpResponse retrieveIdpResponseForLinking(@NonNull Context context) {
+        Preconditions.checkNotNull(context);
+        SharedPreferences sharedPreferences =
+                context.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
+        String email = sharedPreferences.getString(KEY_EMAIL, null);
+        String provider = sharedPreferences.getString(KEY_PROVIDER, null);
+        String idpToken = sharedPreferences.getString(KEY_IDP_TOKEN, null);
+        String idpSecret = sharedPreferences.getString(KEY_IDP_SECRET, null);
+
+        IdpResponse response = null;
+        if (email != null && provider != null && idpToken != null) {
+            response = new IdpResponse.Builder(new User.Builder(provider, email).build())
+                    .setToken(idpToken)
+                    .setSecret(idpSecret)
+                    .setNewUser(false)
+                    .build();
+        }
+        return response;
+    }
+
+
+    public void clearAllData(@NonNull Context context) {
+        Preconditions.checkNotNull(context);
+        SharedPreferences sharedPreferences =
+                context.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
+        SharedPreferences.Editor editor = sharedPreferences.edit();
+        for (String key : KEYS) {
+            editor.remove(key);
+        }
+        editor.apply();
+    }
+}
diff --git a/auth/src/main/java/com/firebase/ui/auth/util/data/ProviderUtils.java b/auth/src/main/java/com/firebase/ui/auth/util/data/ProviderUtils.java
index c39df8d86..b8c05183c 100644
--- a/auth/src/main/java/com/firebase/ui/auth/util/data/ProviderUtils.java
+++ b/auth/src/main/java/com/firebase/ui/auth/util/data/ProviderUtils.java
@@ -20,6 +20,8 @@
 import android.text.TextUtils;
 
 import com.firebase.ui.auth.AuthUI;
+import com.firebase.ui.auth.ErrorCodes;
+import com.firebase.ui.auth.FirebaseUiException;
 import com.firebase.ui.auth.IdpResponse;
 import com.firebase.ui.auth.data.model.FlowParameters;
 import com.google.android.gms.auth.api.credentials.IdentityProviders;
@@ -39,6 +41,8 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import static com.firebase.ui.auth.AuthUI.EMAIL_LINK_PROVIDER;
+
 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 public final class ProviderUtils {
     private static final String GITHUB_IDENTITY = "https://github.com";
@@ -89,8 +93,9 @@ public static String signInMethodToProviderId(@NonNull String method) {
             case PhoneAuthProvider.PHONE_SIGN_IN_METHOD:
                 return PhoneAuthProvider.PROVIDER_ID;
             case EmailAuthProvider.EMAIL_PASSWORD_SIGN_IN_METHOD:
-            case EmailAuthProvider.EMAIL_LINK_SIGN_IN_METHOD:
                 return EmailAuthProvider.PROVIDER_ID;
+            case EmailAuthProvider.EMAIL_LINK_SIGN_IN_METHOD:
+                return EMAIL_LINK_PROVIDER;
             default:
                 throw new IllegalStateException("Unknown method: " + method);
         }
@@ -100,7 +105,8 @@ public static String signInMethodToProviderId(@NonNull String method) {
      * Translate a Firebase Auth provider ID (such as {@link GoogleAuthProvider#PROVIDER_ID}) to a
      * Credentials API account type (such as {@link IdentityProviders#GOOGLE}).
      */
-    public static String providerIdToAccountType(@AuthUI.SupportedProvider @NonNull String providerId) {
+    public static String providerIdToAccountType(
+            @AuthUI.SupportedProvider @NonNull String providerId) {
         switch (providerId) {
             case GoogleAuthProvider.PROVIDER_ID:
                 return IdentityProviders.GOOGLE;
@@ -140,7 +146,9 @@ public static String accountTypeToProviderId(@NonNull String accountType) {
     @Nullable
     public static AuthUI.IdpConfig getConfigFromIdps(List<AuthUI.IdpConfig> idps, String id) {
         for (AuthUI.IdpConfig idp : idps) {
-            if (idp.getProviderId().equals(id)) { return idp; }
+            if (idp.getProviderId().equals(id)) {
+                return idp;
+            }
         }
         return null;
     }
@@ -163,11 +171,13 @@ public static Task<List<String>> fetchSortedProviders(@NonNull FirebaseAuth auth
         }
 
         return auth.fetchSignInMethodsForEmail(email)
-                .continueWith(new Continuation<SignInMethodQueryResult, List<String>>() {
+                .continueWithTask(new Continuation<SignInMethodQueryResult, Task<List<String>>>() {
                     @Override
-                    public List<String> then(@NonNull Task<SignInMethodQueryResult> task) {
+                    public Task<List<String>> then(@NonNull Task<SignInMethodQueryResult> task) {
                         List<String> methods = task.getResult().getSignInMethods();
-                        if (methods == null) { methods = new ArrayList<>(); }
+                        if (methods == null) {
+                            methods = new ArrayList<>();
+                        }
 
                         List<String> allowedProviders = new ArrayList<>(params.providers.size());
                         for (AuthUI.IdpConfig provider : params.providers) {
@@ -182,15 +192,23 @@ public List<String> then(@NonNull Task<SignInMethodQueryResult> task) {
                             }
                         }
 
+                        if (task.isSuccessful() && lastSignedInProviders.isEmpty()
+                                && !methods.isEmpty()) {
+                            // There is an existing user who only has unsupported sign in methods
+                            return Tasks.forException(new FirebaseUiException(ErrorCodes
+                                    .DEVELOPER_ERROR));
+                        }
                         // Reorder providers from most to least usable. Usability is determined by
                         // how many steps a user needs to perform to log in.
                         maximizePriority(lastSignedInProviders, GoogleAuthProvider.PROVIDER_ID);
 
-                        return lastSignedInProviders;
+                        return Tasks.forResult(lastSignedInProviders);
                     }
 
                     private void maximizePriority(List<String> providers, String id) {
-                        if (providers.remove(id)) { providers.add(0, id); }
+                        if (providers.remove(id)) {
+                            providers.add(0, id);
+                        }
                     }
                 });
     }
@@ -200,16 +218,18 @@ public static Task<String> fetchTopProvider(
             @NonNull FlowParameters params,
             @NonNull String email) {
         return fetchSortedProviders(auth, params, email)
-                .continueWith(new Continuation<List<String>, String>() {
+                .continueWithTask(new Continuation<List<String>, Task<String>>() {
                     @Override
-                    public String then(@NonNull Task<List<String>> task) {
-                        if (!task.isSuccessful()) return null;
+                    public Task<String> then(@NonNull Task<List<String>> task) {
+                        if (!task.isSuccessful()) {
+                            return Tasks.forException(task.getException());
+                        }
                         List<String> providers = task.getResult();
 
                         if (providers.isEmpty()) {
-                            return null;
+                            return Tasks.forResult(null);
                         } else {
-                            return providers.get(0);
+                            return Tasks.forResult(providers.get(0));
                         }
                     }
                 });
diff --git a/auth/src/main/java/com/firebase/ui/auth/util/ui/TextHelper.java b/auth/src/main/java/com/firebase/ui/auth/util/ui/TextHelper.java
new file mode 100644
index 000000000..8a137a653
--- /dev/null
+++ b/auth/src/main/java/com/firebase/ui/auth/util/ui/TextHelper.java
@@ -0,0 +1,30 @@
+package com.firebase.ui.auth.util.ui;
+
+import android.graphics.Typeface;
+import android.support.annotation.NonNull;
+import android.support.annotation.RestrictTo;
+import android.text.Spannable;
+import android.text.SpannableStringBuilder;
+import android.text.style.StyleSpan;
+
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+public class TextHelper {
+
+    public static void boldAllOccurencesOfText(@NonNull SpannableStringBuilder builder,
+                                               @NonNull String text,
+                                               @NonNull String textToBold) {
+        int fromIndex = 0;
+        while (fromIndex < text.length()) {
+            int start = text.indexOf(textToBold, fromIndex);
+            int end = start + textToBold.length();
+            if (start == -1 || end >= text.length()) {
+                break;
+            }
+            builder.setSpan(new StyleSpan(Typeface.BOLD),
+                    start,
+                    end,
+                    Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
+            fromIndex = end + 1;
+        }
+    }
+}
diff --git a/auth/src/main/java/com/firebase/ui/auth/viewmodel/RequestCodes.java b/auth/src/main/java/com/firebase/ui/auth/viewmodel/RequestCodes.java
index 9864e54a7..83c530dab 100644
--- a/auth/src/main/java/com/firebase/ui/auth/viewmodel/RequestCodes.java
+++ b/auth/src/main/java/com/firebase/ui/auth/viewmodel/RequestCodes.java
@@ -40,6 +40,15 @@ public final class RequestCodes {
     /** Request code for retrieving a GitHub credential. */
     public static final int GITHUB_PROVIDER = 111;
 
+    /** Request code for starting an email link welcome back flow. */
+    public static final int WELCOME_BACK_EMAIL_LINK_FLOW = 112;
+
+    /** Request code for recovering from opening an email link from the wrong device */
+    public static final int EMAIL_LINK_WRONG_DEVICE_FLOW = 113;
+
+    /** Request code for recovering from opening an invalid email link */
+    public static final int EMAIL_LINK_INVALID_LINK_FLOW = 114;
+
     private RequestCodes() {
         throw new AssertionError("No instance for you!");
     }
diff --git a/auth/src/main/java/com/firebase/ui/auth/viewmodel/email/EmailLinkSendEmailHandler.java b/auth/src/main/java/com/firebase/ui/auth/viewmodel/email/EmailLinkSendEmailHandler.java
new file mode 100644
index 000000000..0f45bbb02
--- /dev/null
+++ b/auth/src/main/java/com/firebase/ui/auth/viewmodel/email/EmailLinkSendEmailHandler.java
@@ -0,0 +1,41 @@
+package com.firebase.ui.auth.viewmodel.email;
+
+import android.app.Application;
+import android.support.annotation.NonNull;
+
+import com.firebase.ui.auth.IdpResponse;
+import com.firebase.ui.auth.util.data.EmailLinkPersistenceManager;
+import com.firebase.ui.auth.data.model.Resource;
+import com.firebase.ui.auth.viewmodel.AuthViewModelBase;
+import com.google.android.gms.tasks.OnCompleteListener;
+import com.google.android.gms.tasks.Task;
+import com.google.firebase.auth.ActionCodeSettings;
+
+public class EmailLinkSendEmailHandler extends AuthViewModelBase<String> {
+    public EmailLinkSendEmailHandler(Application application) {
+        super(application);
+    }
+
+    public void sendSignInLinkToEmail(@NonNull final String email, @NonNull final
+    ActionCodeSettings actionCodeSettings) {
+        if (getAuth() == null) {
+            return;
+        }
+        setResult(Resource.<String>forLoading());
+
+        getAuth().sendSignInLinkToEmail(email, actionCodeSettings)
+                .addOnCompleteListener(new OnCompleteListener<Void>() {
+                    @Override
+                    public void onComplete(@NonNull Task<Void> task) {
+                        if (task.isSuccessful()) {
+                            EmailLinkPersistenceManager.getInstance().saveEmailForLink(getApplication(),
+                                    email);
+                            setResult(Resource.forSuccess(email));
+                        } else {
+                            setResult(Resource.<String>forFailure(task.getException()));
+                        }
+                    }
+                });
+    }
+
+}
diff --git a/auth/src/main/java/com/firebase/ui/auth/viewmodel/email/EmailLinkSignInHandler.java b/auth/src/main/java/com/firebase/ui/auth/viewmodel/email/EmailLinkSignInHandler.java
new file mode 100644
index 000000000..1bf097899
--- /dev/null
+++ b/auth/src/main/java/com/firebase/ui/auth/viewmodel/email/EmailLinkSignInHandler.java
@@ -0,0 +1,193 @@
+package com.firebase.ui.auth.viewmodel.email;
+
+import android.app.Application;
+import android.support.annotation.NonNull;
+
+import com.firebase.ui.auth.ErrorCodes;
+import com.firebase.ui.auth.FirebaseUiException;
+import com.firebase.ui.auth.IdpResponse;
+import com.firebase.ui.auth.util.data.EmailLinkPersistenceManager;
+import com.firebase.ui.auth.data.model.Resource;
+import com.firebase.ui.auth.data.model.User;
+import com.firebase.ui.auth.data.remote.ProfileMerger;
+import com.firebase.ui.auth.util.data.AuthOperationManager;
+import com.firebase.ui.auth.util.data.EmailLinkParser;
+import com.firebase.ui.auth.util.data.ProviderUtils;
+import com.firebase.ui.auth.util.data.TaskFailureLogger;
+import com.firebase.ui.auth.viewmodel.SignInViewModelBase;
+import com.google.android.gms.tasks.Continuation;
+import com.google.android.gms.tasks.OnCompleteListener;
+import com.google.android.gms.tasks.OnFailureListener;
+import com.google.android.gms.tasks.OnSuccessListener;
+import com.google.android.gms.tasks.Task;
+import com.google.firebase.auth.ActionCodeResult;
+import com.google.firebase.auth.AuthCredential;
+import com.google.firebase.auth.AuthResult;
+import com.google.firebase.auth.EmailAuthProvider;
+import com.google.firebase.auth.FirebaseAuthUserCollisionException;
+import com.google.firebase.auth.FirebaseUser;
+
+import static com.firebase.ui.auth.AuthUI.EMAIL_LINK_PROVIDER;
+
+public class EmailLinkSignInHandler extends SignInViewModelBase {
+    private static final String TAG = "EmailLinkSignInHandler";
+
+    public EmailLinkSignInHandler(Application application) {
+        super(application);
+    }
+
+    public void startSignIn() {
+        setResult(Resource.<IdpResponse>forLoading());
+
+        String link = getArguments().emailLink;
+        if (!getAuth().isSignInWithEmailLink(link)) {
+            setResult(Resource.<IdpResponse>forFailure(new FirebaseUiException(ErrorCodes
+                    .INVALID_EMAIL_LINK_ERROR)));
+            return;
+        }
+
+        final EmailLinkPersistenceManager persistenceManager = EmailLinkPersistenceManager
+                .getInstance();
+        final AuthOperationManager authOperationManager = AuthOperationManager.getInstance();
+        final IdpResponse response = persistenceManager.retrieveIdpResponseForLinking
+                (getApplication());
+        final String email = persistenceManager.retrieveEmailForLink(getApplication());
+
+        persistenceManager.clearAllData(getApplication());
+
+        if (email == null && response == null) {
+            determineErrorFlowAndFinish(link);
+        } else if (response != null) {
+            handleLinkingFlow(authOperationManager, persistenceManager, response, link);
+        } else {
+            handleNormalFlow(authOperationManager, persistenceManager, email, link);
+        }
+    }
+
+    private void determineErrorFlowAndFinish(String link) {
+        String oobCode = EmailLinkParser.getInstance().getOobCodeFromLink(link);
+        getAuth().checkActionCode(oobCode).addOnCompleteListener(
+                new OnCompleteListener<ActionCodeResult>() {
+                    @Override
+                    public void onComplete(@NonNull Task<ActionCodeResult> task) {
+                        if (task.isSuccessful()) {
+                            setResult(Resource.<IdpResponse>forFailure(new FirebaseUiException
+                                    (ErrorCodes
+                                            .EMAIL_LINK_WRONG_DEVICE_ERROR)));
+                        } else {
+                            setResult(Resource.<IdpResponse>forFailure(new FirebaseUiException
+                                    (ErrorCodes
+                                            .INVALID_EMAIL_LINK_ERROR)));
+                        }
+                    }
+                });
+    }
+
+    private void handleLinkingFlow(final AuthOperationManager authOperationManager,
+                                   final EmailLinkPersistenceManager persistenceManager,
+                                   final IdpResponse response,
+                                   final String link) {
+        final AuthCredential storedCredentialForLink = ProviderUtils.getAuthCredential
+                (response);
+        final AuthCredential emailLinkCredential = EmailAuthProvider.getCredentialWithLink
+                (response.getEmail(), link);
+
+        if (authOperationManager.canUpgradeAnonymous(getAuth(), getArguments())) {
+            authOperationManager.safeLink(emailLinkCredential,
+                    storedCredentialForLink, getArguments())
+                    .addOnCompleteListener(new OnCompleteListener<AuthResult>() {
+                        @Override
+                        public void onComplete(@NonNull Task<AuthResult> task) {
+                            persistenceManager.clearAllData(getApplication());
+                            if (task.isSuccessful()) {
+                                handleMergeFailure(storedCredentialForLink);
+                            } else {
+                                setResult(Resource.<IdpResponse>forFailure(task.getException
+                                        ()));
+                            }
+                        }
+                    });
+        } else {
+            getAuth().signInWithCredential(emailLinkCredential)
+                    .continueWithTask(new Continuation<AuthResult, Task<AuthResult>>() {
+                        @Override
+                        public Task<AuthResult> then(@NonNull Task<AuthResult> task) {
+                            persistenceManager.clearAllData(getApplication());
+                            if (!task.isSuccessful()) {
+                                return task;
+                            }
+                            return task.getResult().getUser()
+                                    .linkWithCredential(storedCredentialForLink)
+                                    .continueWithTask(new ProfileMerger(response))
+                                    .addOnFailureListener(new TaskFailureLogger(TAG,
+                                            "linkWithCredential+merge failed."));
+                        }
+                    })
+                    .addOnSuccessListener(new OnSuccessListener<AuthResult>() {
+                        @Override
+                        public void onSuccess(AuthResult authResult) {
+                            FirebaseUser user = authResult.getUser();
+                            IdpResponse response = new IdpResponse.Builder(
+                                    new User.Builder(EmailAuthProvider
+                                            .EMAIL_LINK_SIGN_IN_METHOD,
+                                            user.getEmail())
+                                            .setName(user.getDisplayName())
+                                            .setPhotoUri(user.getPhotoUrl())
+                                            .build())
+                                    .build();
+                            handleSuccess(response, authResult);
+                        }
+                    })
+                    .addOnFailureListener(new OnFailureListener() {
+                        @Override
+                        public void onFailure(@NonNull Exception e) {
+                            setResult(Resource.<IdpResponse>forFailure(e));
+                        }
+                    });
+        }
+    }
+
+    private void handleNormalFlow(final AuthOperationManager authOperationManager,
+                                  final EmailLinkPersistenceManager persistenceManager,
+                                  final String email,
+                                  final String link) {
+        final AuthCredential emailLinkCredential = EmailAuthProvider.getCredentialWithLink(email,
+                link);
+
+        // Bug in core SDK - credential is mutated and won't be usable for sign in, so create
+        // a new one to pass back. b/117425827
+        final AuthCredential emailLinkCredentialForLinking = EmailAuthProvider
+                .getCredentialWithLink(email,
+                        link);
+        // Either regular sign in or anonymous user upgrade
+        authOperationManager.signInAndLinkWithCredential(getAuth(), getArguments(),
+                emailLinkCredential)
+                .addOnSuccessListener(new OnSuccessListener<AuthResult>() {
+                    @Override
+                    public void onSuccess(AuthResult authResult) {
+                        persistenceManager.clearAllData(getApplication());
+
+                        FirebaseUser user = authResult.getUser();
+                        IdpResponse response = new IdpResponse.Builder(
+                                new User.Builder(EMAIL_LINK_PROVIDER,
+                                        user.getEmail())
+                                        .setName(user.getDisplayName())
+                                        .setPhotoUri(user.getPhotoUrl())
+                                        .build())
+                                .build();
+                        handleSuccess(response, authResult);
+                    }
+                })
+                .addOnFailureListener(new OnFailureListener() {
+                    @Override
+                    public void onFailure(@NonNull Exception e) {
+                        persistenceManager.clearAllData(getApplication());
+                        if (e instanceof FirebaseAuthUserCollisionException) {
+                            handleMergeFailure(emailLinkCredentialForLinking);
+                        } else {
+                            setResult(Resource.<IdpResponse>forFailure(e));
+                        }
+                    }
+                });
+    }
+}
diff --git a/auth/src/main/java/com/firebase/ui/auth/viewmodel/email/EmailProviderResponseHandler.java b/auth/src/main/java/com/firebase/ui/auth/viewmodel/email/EmailProviderResponseHandler.java
index fb327a9a7..d2d75c542 100644
--- a/auth/src/main/java/com/firebase/ui/auth/viewmodel/email/EmailProviderResponseHandler.java
+++ b/auth/src/main/java/com/firebase/ui/auth/viewmodel/email/EmailProviderResponseHandler.java
@@ -9,6 +9,7 @@
 import com.firebase.ui.auth.data.model.Resource;
 import com.firebase.ui.auth.data.model.User;
 import com.firebase.ui.auth.data.remote.ProfileMerger;
+import com.firebase.ui.auth.ui.email.WelcomeBackEmailLinkPrompt;
 import com.firebase.ui.auth.ui.email.WelcomeBackPasswordPrompt;
 import com.firebase.ui.auth.ui.idp.WelcomeBackIdpPrompt;
 import com.firebase.ui.auth.util.data.AuthOperationManager;
@@ -23,6 +24,8 @@
 import com.google.firebase.auth.EmailAuthProvider;
 import com.google.firebase.auth.FirebaseAuthUserCollisionException;
 
+import static com.firebase.ui.auth.AuthUI.EMAIL_LINK_PROVIDER;
+
 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 public class EmailProviderResponseHandler extends SignInViewModelBase {
     private static final String TAG = "EmailProviderResponseHa";
@@ -109,6 +112,16 @@ public void onSuccess(String provider) {
                                 ).build()),
                         RequestCodes.WELCOME_BACK_EMAIL_FLOW
                 )));
+            } else if (EMAIL_LINK_PROVIDER.equalsIgnoreCase(provider)) {
+                setResult(Resource.<IdpResponse>forFailure(new IntentRequiredException(
+                        WelcomeBackEmailLinkPrompt.createIntent(
+                                getApplication(),
+                                getArguments(),
+                                new IdpResponse.Builder(new User.Builder(
+                                        EMAIL_LINK_PROVIDER, mEmail).build()
+                                ).build()),
+                        RequestCodes.WELCOME_BACK_EMAIL_LINK_FLOW
+                )));
             } else {
                 setResult(Resource.<IdpResponse>forFailure(new IntentRequiredException(
                         WelcomeBackIdpPrompt.createIntent(
diff --git a/auth/src/main/java/com/firebase/ui/auth/viewmodel/idp/SocialProviderResponseHandler.java b/auth/src/main/java/com/firebase/ui/auth/viewmodel/idp/SocialProviderResponseHandler.java
index 1cda55034..7f767b656 100644
--- a/auth/src/main/java/com/firebase/ui/auth/viewmodel/idp/SocialProviderResponseHandler.java
+++ b/auth/src/main/java/com/firebase/ui/auth/viewmodel/idp/SocialProviderResponseHandler.java
@@ -15,6 +15,7 @@
 import com.firebase.ui.auth.data.model.Resource;
 import com.firebase.ui.auth.data.model.User;
 import com.firebase.ui.auth.data.remote.ProfileMerger;
+import com.firebase.ui.auth.ui.email.WelcomeBackEmailLinkPrompt;
 import com.firebase.ui.auth.ui.email.WelcomeBackPasswordPrompt;
 import com.firebase.ui.auth.ui.idp.WelcomeBackIdpPrompt;
 import com.firebase.ui.auth.util.data.AuthOperationManager;
@@ -30,6 +31,8 @@
 
 import java.util.List;
 
+import static com.firebase.ui.auth.AuthUI.EMAIL_LINK_PROVIDER;
+
 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 public class SocialProviderResponseHandler extends SignInViewModelBase {
     public SocialProviderResponseHandler(Application application) {
@@ -125,6 +128,15 @@ public void startWelcomeBackFlowForLinking(String provider, IdpResponse response
                             response),
                     RequestCodes.ACCOUNT_LINK_FLOW
             )));
+        } else if (provider.equals(EMAIL_LINK_PROVIDER)) {
+            // Start email link welcome back flow
+            setResult(Resource.<IdpResponse>forFailure(new IntentRequiredException(
+                    WelcomeBackEmailLinkPrompt.createIntent(
+                            getApplication(),
+                            getArguments(),
+                            response),
+                    RequestCodes.WELCOME_BACK_EMAIL_LINK_FLOW
+            )));
         } else {
             // Start Idp welcome back flow
             setResult(Resource.<IdpResponse>forFailure(new IntentRequiredException(
diff --git a/auth/src/main/res/layout/fui_email_link_sign_in_layout.xml b/auth/src/main/res/layout/fui_email_link_sign_in_layout.xml
new file mode 100644
index 000000000..8f14d49e5
--- /dev/null
+++ b/auth/src/main/res/layout/fui_email_link_sign_in_layout.xml
@@ -0,0 +1,63 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical"
+    tools:ignore="MissingDefaultResource">
+
+    <FrameLayout
+        android:id="@+id/invisible_frame"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        tools:ignore="MergeRootFrame" />
+
+    <ScrollView
+        android:id="@+id/top_level_view"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <LinearLayout
+            style="@style/FirebaseUI.WrapperStyle"
+            android:layout_height="wrap_content"
+            android:orientation="vertical">
+
+            <TextView
+                android:id="@+id/sign_in_email_sent_header_text"
+                style="@style/FirebaseUI.Text.Heading"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_gravity="top"
+                android:text="@string/fui_email_link_header"
+                android:textStyle="bold" />
+
+            <TextView
+                android:id="@+id/sign_in_email_sent_text"
+                style="@style/FirebaseUI.Text.BodyText"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:textIsSelectable="false" />
+
+            <TextView
+                android:id="@+id/welcome_back_email_link_body"
+                style="@style/FirebaseUI.Text.BodyText"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:textIsSelectable="false" />
+
+            <TextView
+                android:id="@+id/trouble_signing_in"
+                style="@style/FirebaseUI.Text.Link"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:text="@string/fui_trouble_signing_in" />
+
+            <TextView
+                android:id="@+id/email_footer_tos_and_pp_text"
+                style="@style/FirebaseUI.PrivacyFooter" />
+
+        </LinearLayout>
+
+    </ScrollView>
+
+</LinearLayout>
\ No newline at end of file
diff --git a/auth/src/main/res/layout/fui_email_link_trouble_signing_in_layout.xml b/auth/src/main/res/layout/fui_email_link_trouble_signing_in_layout.xml
new file mode 100644
index 000000000..1cd5e5b08
--- /dev/null
+++ b/auth/src/main/res/layout/fui_email_link_trouble_signing_in_layout.xml
@@ -0,0 +1,54 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    tools:ignore="MissingDefaultResource"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical">
+
+    <me.zhanghai.android.materialprogressbar.MaterialProgressBar
+        android:id="@+id/top_progress_bar"
+        style="@style/FirebaseUI.TopProgressBar"
+        tools:visibility="visible" />
+
+    <ScrollView
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <LinearLayout
+            style="@style/FirebaseUI.WrapperStyle"
+            android:layout_height="wrap_content"
+            android:orientation="vertical">
+
+            <TextView
+                android:id="@+id/heading"
+                style="@style/FirebaseUI.Text.Heading"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:text="@string/fui_email_link_trouble_getting_email_header" />
+
+            <TextView
+                android:id="@+id/trouble_signing_in_possible_fixes"
+                style="@style/FirebaseUI.Text.BodyText"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="@dimen/fui_field_padding_vert"
+                android:textIsSelectable="false"
+                android:text="@string/fui_email_link_trouble_getting_possible_fixes" />
+
+            <Button
+                android:id="@+id/button_resend_email"
+                style="@style/FirebaseUI.Button"
+                android:text="@string/fui_email_link_resend" />
+
+            <TextView
+                android:id="@+id/email_footer_tos_and_pp_text"
+                style="@style/FirebaseUI.PrivacyFooter" />
+
+        </LinearLayout>
+
+    </ScrollView>
+
+</LinearLayout>
\ No newline at end of file
diff --git a/auth/src/main/res/layout/fui_welcome_back_email_link_prompt_layout.xml b/auth/src/main/res/layout/fui_welcome_back_email_link_prompt_layout.xml
new file mode 100644
index 000000000..27b5a9afc
--- /dev/null
+++ b/auth/src/main/res/layout/fui_welcome_back_email_link_prompt_layout.xml
@@ -0,0 +1,59 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    tools:ignore="MissingDefaultResource"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical">
+
+    <me.zhanghai.android.materialprogressbar.MaterialProgressBar
+        android:id="@+id/top_progress_bar"
+        style="@style/FirebaseUI.TopProgressBar"
+        tools:visibility="visible" />
+
+    <ScrollView
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <android.support.constraint.ConstraintLayout
+            style="@style/FirebaseUI.WrapperStyle"
+            android:layout_height="wrap_content">
+
+            <TextView
+                android:id="@+id/heading"
+                style="@style/FirebaseUI.Text.Heading"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:text="@string/fui_welcome_back_email_link_header"
+                app:layout_constraintTop_toTopOf="parent" />
+
+            <TextView
+                android:id="@+id/welcome_back_email_link_body"
+                style="@style/FirebaseUI.Text.BodyText"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="@dimen/fui_field_padding_vert"
+                android:textIsSelectable="false"
+                app:layout_constraintTop_toBottomOf="@+id/heading" />
+
+            <Button
+                android:id="@+id/button_sign_in"
+                style="@style/FirebaseUI.Button"
+                android:text="@string/fui_sign_in_default"
+                android:layout_marginTop="@dimen/fui_field_padding_vert"
+                app:layout_constraintTop_toBottomOf="@+id/welcome_back_email_link_body"
+                app:layout_constraintEnd_toEndOf="parent" />
+
+            <TextView
+                android:id="@+id/email_footer_tos_and_pp_text"
+                style="@style/FirebaseUI.PrivacyFooter"
+                app:layout_constraintTop_toBottomOf="@+id/button_sign_in"
+                app:layout_constraintBottom_toBottomOf="parent" />
+
+        </android.support.constraint.ConstraintLayout>
+
+    </ScrollView>
+
+</LinearLayout>
\ No newline at end of file
diff --git a/auth/src/main/res/values/strings.xml b/auth/src/main/res/values/strings.xml
index 8eab9e43e..b736795c2 100644
--- a/auth/src/main/res/values/strings.xml
+++ b/auth/src/main/res/values/strings.xml
@@ -1,4 +1,4 @@
-<resources xmlns:tools="http://schemas.android.com/tools" xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
+<resources xmlns:tools="http://schemas.android.com/tools" xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2" tools:ignore="ExtraTranslation">
     <string name="app_name" translatable="false" tools:ignore="ResourceName">ui_flow</string>
 
     <!-- Common -->
@@ -52,6 +52,8 @@
     <string name="fui_title_welcome_back_password_prompt" translatable="false">@string/fui_sign_in_default</string>
     <string name="fui_welcome_back_idp_header" translation_description="Inline subtitle to users whose signup was interrupted since an existing account was detected">You already have an account</string>
     <string name="fui_welcome_back_email_header" translation_description="Message for returning users">Welcome back!</string>
+    <string name="fui_welcome_back_email_link_header" translation_description="Message for returning users">You already have an account\n</string>
+
     <string name="fui_welcome_back_idp_prompt" translation_description="Message to users that need to signin using existing IDP accounts">
         You\'ve already used <xliff:g example="jane.doe@example.com" id="email_addr" translation_description="">%1$s</xliff:g>.
         Sign in with <xliff:g example="Google" id="provider_name" translation_description="">%2$s</xliff:g> to continue.
@@ -60,6 +62,10 @@
         You\'ve already used <xliff:g example="jane.doe@example.com" id="email_addr" translation_description="">%1$s</xliff:g>
         to sign in. Enter your password for that account.
     </string>
+    <string name="fui_welcome_back_email_link_prompt_body" translation_description="Message to users that need to signin using existing email link accounts">
+        You\'ve already used <xliff:g example="jane.doe@example.com" id="email_addr" translation_description="">%1$s</xliff:g>.
+        You can connect your %2$s account with %1$s by signing in with email link below.\n\nFor this flow to successfully connect your %2$s account with this email, you have to open the link on the same device or browser.
+    </string>
     <string name="fui_progress_dialog_signing_in" translation_description="Progress dialog text">Signing in…</string>
     <string name="fui_trouble_signing_in" translation_description="Link leading to forgot password flow">Trouble signing in?</string>
 
@@ -70,7 +76,7 @@
         reset your password.</string>
     <string name="fui_button_text_send" translation_description="Button text to send recovery email">Send</string>
     <string name="fui_confirm_recovery_body" translation_description="Alert dialog displayed after password recovery email is sent">Follow the instructions sent to %1$s to recover your password.</string>
-    <string name="fui_progress_dialog_sending" translation_description="Progress dialog while password recovery email is being sent">Sending…</string>
+    <string name="fui_progress_dialog_sending" translation_description="Progress dialog while password recovery email or email link is being sent">Sending…</string>
     <string name="fui_error_email_does_not_exist" translation_description="Inline error when user attempt signin with invalid account">That email address doesn\'t match an existing account</string>
 
     <!-- Other error messages -->
@@ -80,6 +86,21 @@
     <!-- Accessibility -->
     <string name="fui_accessibility_logo" translation_description="Content description for app logo">App logo</string>
 
+
+    <!-- Email Link Sign In -->
+    <string name="fui_email_link_header" translation_description="Email link sign in email sent header">Sign-in email sent\n</string>
+    <string name="fui_email_link_email_sent" translation_description="Text to tell the user that the email has been sent">A sign-in email with additional instructions was sent to %1$s. Check your email to complete sign-in.</string>
+    <string name="fui_email_link_trouble_getting_email_header" translation_description="Header that is displayed on the trouble signing in activity">Trouble getting email?</string>
+    <string name="fui_email_link_trouble_getting_possible_fixes" translation_description="A list of possible fixes for receiving the email">Try these common fixes:\n\u2022 Check if the email was marked as spam or filtered.\n\u2022 Check your internet connection.\n\u2022 Check that you did not misspell your email.\n\u2022 Check that your inbox space is not running out or other inbox setting related issues.\n</string>
+    <string name="fui_email_link_trouble_getting_email_resend_solution" translation_description="Prompt the user to resend the email if the listed fixes do not work">If the steps above didn\'t work, you can resend the email. Note that this will deactivate the link in the older email. </string>
+    <string name="fui_email_link_resend" translation_description="Button text to resend">Resend</string>
+    <string name="fui_email_link_wrong_device_header" translation_description="Header shown when the user opens a link that was sent from a different device">New device or browser detected.</string>
+    <string name="fui_email_link_wrong_device_message" translation_description="Message shown when the user opens a link that was sent from a different device">Try opening the link using the same device or browser where you started the sign-in process.</string>
+    <string name="fui_email_link_invalid_link_header" translation_description="Header shown when the user opens a link that was sent from a different device">Invalid email link.</string>
+    <string name="fui_email_link_invalid_link_message" translation_description="Message shown when the user opens a link that was sent from a different device">The email link is invalid. This can occur if the email link is expired or was already used to sign in. Please restart the login flow.</string>
+    <string name="fui_email_link_dismiss_button" translation_description="Dismiss button for the wrong device or invalid link dialog">Dismiss</string>
+
+
     <!-- Phone number auth -->
     <string name="fui_verify_phone_number_title" translation_description="Phone number entry form title">Enter your phone number</string>
     <string name="fui_invalid_phone_number" translation_description="Inline error when phone number entered is invalid">Enter a valid phone number</string>
@@ -98,4 +119,6 @@
     <string name="fui_continue_phone_login" translation_description="Button text to submit phone number and send sms">Continue</string>
     <string name="fui_sms_terms_of_service" translation_description="Fine print warning displayed below Verify Phone Number button">By tapping “%1$s”, an SMS may be sent. Message &amp; data rates may apply.</string>
     <string name="fui_sms_terms_of_service_and_privacy_policy_extended" translation_description="Fine print warning displayed below Verify Phone Number button">By tapping “%1$s”, you are indicating that you accept our <xliff:g example="https://google.com/terms" id="tos" translation_description="">%2$s</xliff:g> and <xliff:g example="https://google.com/privacy" id="pp" translation_description="">%3$s</xliff:g>. An SMS may be sent. Message &amp; data rates may apply.</string>
+
+
 </resources>
diff --git a/auth/src/test/java/com/firebase/ui/auth/AuthUITest.java b/auth/src/test/java/com/firebase/ui/auth/AuthUITest.java
index f5ef5d526..a5620c36e 100644
--- a/auth/src/test/java/com/firebase/ui/auth/AuthUITest.java
+++ b/auth/src/test/java/com/firebase/ui/auth/AuthUITest.java
@@ -20,6 +20,7 @@
 import com.firebase.ui.auth.testhelpers.TestConstants;
 import com.firebase.ui.auth.testhelpers.TestHelper;
 import com.firebase.ui.auth.util.ExtraConstants;
+import com.google.firebase.auth.ActionCodeSettings;
 import com.google.firebase.auth.EmailAuthProvider;
 
 import org.junit.Before;
@@ -31,10 +32,12 @@
 import java.util.Arrays;
 import java.util.List;
 
+import static com.google.common.truth.Truth.assertThat;
 import static junit.framework.Assert.assertEquals;
 
 @RunWith(RobolectricTestRunner.class)
 public class AuthUITest {
+    private static final String URL = "url";
     private AuthUI mAuthUi;
 
     @Before
@@ -173,7 +176,8 @@ public void testPhoneBuilder_withValidDefaultIso_expectSucess() {
     }
 
     @Test(expected = IllegalStateException.class)
-    public void testPhoneBuilder_setBothBlacklistedAndWhitelistedCountries_expectIllegalStateException() {
+    public void
+    testPhoneBuilder_setBothBlacklistedAndWhitelistedCountries_expectIllegalStateException() {
         List<String> countries = Arrays.asList("ca");
         new IdpConfig.PhoneBuilder()
                 .setBlacklistedCountries(countries)
@@ -182,7 +186,8 @@ public void testPhoneBuilder_setBothBlacklistedAndWhitelistedCountries_expectIll
     }
 
     @Test(expected = IllegalArgumentException.class)
-    public void testPhoneBuilder_passEmptyListForWhitelistedCountries_expectIllegalArgumentException() {
+    public void
+    testPhoneBuilder_passEmptyListForWhitelistedCountries_expectIllegalArgumentException() {
         new IdpConfig.PhoneBuilder()
                 .setWhitelistedCountries(new ArrayList<String>())
                 .build();
@@ -197,7 +202,8 @@ public void testPhoneBuilder_passNullForWhitelistedCountries_expectNullPointerEx
 
 
     @Test(expected = IllegalArgumentException.class)
-    public void testPhoneBuilder_passEmptyListForBlacklistedCountries_expectIllegalArgumentException() {
+    public void
+    testPhoneBuilder_passEmptyListForBlacklistedCountries_expectIllegalArgumentException() {
         new IdpConfig.PhoneBuilder()
                 .setBlacklistedCountries(new ArrayList<String>())
                 .build();
@@ -216,4 +222,32 @@ public void testAnonymousBuilder_expectSucess() {
                 .build();
     }
 
+    @Test
+    public void
+    testEmailBuilder_withValidActionCodeSettings_expectSuccess() {
+        ActionCodeSettings actionCodeSettings = ActionCodeSettings.newBuilder().setUrl(URL)
+                .setHandleCodeInApp(true)
+                .build();
+        IdpConfig config = new IdpConfig.EmailBuilder().enableEmailLinkSignIn()
+                .setActionCodeSettings
+                        (actionCodeSettings).build();
+        assertThat(config.getParams().getParcelable(ExtraConstants.ACTION_CODE_SETTINGS)).isEqualTo
+                (actionCodeSettings);
+        assertThat(config.getProviderId()).isEqualTo(AuthUI.EMAIL_LINK_PROVIDER);
+
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void testEmailBuilder_withoutActionCodeSettings_expectThrows() {
+        new IdpConfig.EmailBuilder().enableEmailLinkSignIn().build();
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void
+    testEmailBuilder_withActionCodeSettingsAndHandleCodeInAppFalse_expectThrows() {
+        ActionCodeSettings actionCodeSettings = ActionCodeSettings.newBuilder().setUrl(URL)
+                .build();
+        new IdpConfig.EmailBuilder().enableEmailLinkSignIn().setActionCodeSettings
+                (actionCodeSettings).build();
+    }
 }
diff --git a/auth/src/test/java/com/firebase/ui/auth/data/EmailLinkParserTest.java b/auth/src/test/java/com/firebase/ui/auth/data/EmailLinkParserTest.java
new file mode 100644
index 000000000..c60ceee17
--- /dev/null
+++ b/auth/src/test/java/com/firebase/ui/auth/data/EmailLinkParserTest.java
@@ -0,0 +1,53 @@
+package com.firebase.ui.auth.data;
+
+import com.firebase.ui.auth.util.data.EmailLinkParser;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+
+import static com.google.common.truth.Truth.assertThat;
+
+/**
+ * Unit tests for {@link EmailLinkParser}.
+ */
+@RunWith(RobolectricTestRunner.class)
+public class EmailLinkParserTest {
+
+    private static final String OOB_CODE = "anOobCode";
+    private static final String ENCODED_EMAIL_LINK =
+            "https://www.fake.com?link=https://fake.firebaseapp.com/__/auth/action?"
+                    + "%26mode%3DsignIn%26oobCode%3D"
+                    + OOB_CODE;
+    private static final String DECODED_EMAIL_LINK =
+            "https://fake.com/__/auth/action?apiKey=apiKey&mode=signIn"
+                    + "&oobCode="
+                    + OOB_CODE;
+    private static final String MALFORMED_LINK = "not_a_hierarchical_link:";
+
+    private EmailLinkParser mEmailLinkParser;
+
+    @Before
+    public void setUp() {
+        mEmailLinkParser = mEmailLinkParser.getInstance();
+    }
+
+    @Test
+    public void testGetOobCodeFromLink_encodedLink() {
+        String oobCode = mEmailLinkParser.getOobCodeFromLink(ENCODED_EMAIL_LINK);
+        assertThat(oobCode).isEqualTo(OOB_CODE);
+    }
+
+    @Test
+    public void testGetOobCodeFromLink_decodedLink() {
+        String oobCode = mEmailLinkParser.getOobCodeFromLink(DECODED_EMAIL_LINK);
+        assertThat(oobCode).isEqualTo(OOB_CODE);
+    }
+
+    @Test
+    public void testGetOobCodeFromLink_malformedLink() {
+        String oobCode = mEmailLinkParser.getOobCodeFromLink(MALFORMED_LINK);
+        assertThat(oobCode).isNull();
+    }
+}
diff --git a/auth/src/test/java/com/firebase/ui/auth/data/EmailLinkPersistanceManagerTest.java b/auth/src/test/java/com/firebase/ui/auth/data/EmailLinkPersistanceManagerTest.java
new file mode 100644
index 000000000..c9b99a23b
--- /dev/null
+++ b/auth/src/test/java/com/firebase/ui/auth/data/EmailLinkPersistanceManagerTest.java
@@ -0,0 +1,63 @@
+package com.firebase.ui.auth.data;
+
+
+import com.firebase.ui.auth.AuthUI;
+import com.firebase.ui.auth.IdpResponse;
+import com.firebase.ui.auth.util.data.EmailLinkPersistenceManager;
+import com.firebase.ui.auth.data.model.User;
+import com.firebase.ui.auth.testhelpers.TestConstants;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+
+import static com.google.common.truth.Truth.assertThat;
+
+/**
+ * Unit tests for {@link EmailLinkPersistenceManager}.
+ */
+@RunWith(RobolectricTestRunner.class)
+public class EmailLinkPersistanceManagerTest {
+
+
+    EmailLinkPersistenceManager mPersistenceManager;
+
+    @Before
+    public void setUp() {
+        mPersistenceManager = EmailLinkPersistenceManager.getInstance();
+    }
+
+    @Test
+    public void testSaveAndRetrieveEmailForLink() {
+        mPersistenceManager.saveEmailForLink(RuntimeEnvironment.application, TestConstants.EMAIL);
+
+        String savedEmail = mPersistenceManager.retrieveEmailForLink(RuntimeEnvironment
+                .application);
+        assertThat(savedEmail).isEqualTo(TestConstants.EMAIL);
+    }
+
+    @Test
+    public void testSaveAndRetrieveIdpResonseForLinking() {
+        IdpResponse response = buildIdpResponse();
+
+        mPersistenceManager.saveIdpResponseForLinking(RuntimeEnvironment.application, response);
+
+        IdpResponse savedResponse = mPersistenceManager.retrieveIdpResponseForLinking
+                (RuntimeEnvironment.application);
+
+        assertThat(savedResponse).isEqualTo(response);
+    }
+
+    private IdpResponse buildIdpResponse() {
+        User user = new User.Builder(AuthUI.EMAIL_LINK_PROVIDER, TestConstants.EMAIL)
+                .build();
+
+        return new IdpResponse.Builder(user)
+                .setToken(TestConstants.TOKEN)
+                .setSecret(TestConstants.SECRET)
+                .build();
+    }
+
+}
diff --git a/auth/src/test/java/com/firebase/ui/auth/testhelpers/TestHelper.java b/auth/src/test/java/com/firebase/ui/auth/testhelpers/TestHelper.java
index c5d1a0ad4..b9df9e09d 100644
--- a/auth/src/test/java/com/firebase/ui/auth/testhelpers/TestHelper.java
+++ b/auth/src/test/java/com/firebase/ui/auth/testhelpers/TestHelper.java
@@ -23,6 +23,7 @@
 import com.firebase.ui.auth.data.model.FlowParameters;
 import com.google.firebase.FirebaseApp;
 import com.google.firebase.FirebaseOptions;
+import com.google.firebase.auth.ActionCodeSettings;
 import com.google.firebase.auth.EmailAuthProvider;
 import com.google.firebase.auth.FacebookAuthProvider;
 import com.google.firebase.auth.FirebaseAuth;
@@ -38,6 +39,7 @@
 import java.util.Collection;
 import java.util.List;
 
+import static com.firebase.ui.auth.AuthUI.EMAIL_LINK_PROVIDER;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.spy;
@@ -120,6 +122,11 @@ public static FlowParameters getFlowParameters(Collection<String> providerIds,
                 case GithubAuthProvider.PROVIDER_ID:
                     idpConfigs.add(new IdpConfig.GitHubBuilder().build());
                     break;
+                case EMAIL_LINK_PROVIDER:
+                    idpConfigs.add(new IdpConfig.EmailBuilder().enableEmailLinkSignIn()
+                            .setActionCodeSettings(ActionCodeSettings.newBuilder().setUrl("URL")
+                                    .setHandleCodeInApp(true).build()).build());
+                    break;
                 case EmailAuthProvider.PROVIDER_ID:
                     idpConfigs.add(new IdpConfig.EmailBuilder().build());
                     break;
@@ -143,7 +150,8 @@ public static FlowParameters getFlowParameters(Collection<String> providerIds,
                 true,
                 true,
                 enableAnonymousUpgrade,
-                false);
+                false,
+                null);
     }
 
 
diff --git a/auth/src/test/java/com/firebase/ui/auth/ui/email/EmailActivityTest.java b/auth/src/test/java/com/firebase/ui/auth/ui/email/EmailActivityTest.java
index 473b23be7..85614a0bf 100644
--- a/auth/src/test/java/com/firebase/ui/auth/ui/email/EmailActivityTest.java
+++ b/auth/src/test/java/com/firebase/ui/auth/ui/email/EmailActivityTest.java
@@ -18,11 +18,16 @@
 import android.support.design.widget.TextInputLayout;
 import android.widget.Button;
 
+import com.firebase.ui.auth.AuthUI;
+import com.firebase.ui.auth.IdpResponse;
 import com.firebase.ui.auth.R;
+import com.firebase.ui.auth.util.data.EmailLinkPersistenceManager;
 import com.firebase.ui.auth.data.model.User;
 import com.firebase.ui.auth.testhelpers.TestConstants;
 import com.firebase.ui.auth.testhelpers.TestHelper;
+import com.firebase.ui.auth.util.ExtraConstants;
 import com.google.firebase.auth.EmailAuthProvider;
+import com.google.firebase.auth.GoogleAuthProvider;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -33,30 +38,78 @@
 
 import java.util.Collections;
 
+import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.assertEquals;
 
 @RunWith(RobolectricTestRunner.class)
 public class EmailActivityTest {
-    private EmailActivity createActivity() {
-        Intent startIntent = EmailActivity.createIntent(
-                RuntimeEnvironment.application,
-                TestHelper.getFlowParameters(Collections.singletonList(EmailAuthProvider.PROVIDER_ID)));
 
-        return Robolectric.buildActivity(EmailActivity.class, startIntent)
-                .create()
-                .start()
-                .visible()
-                .get();
-    }
+    private static final String EMAIL = "email";
+    private static final String ID_TOKEN = "idToken";
+    private static final String SECRET = "secret";
 
     @Before
     public void setUp() {
         TestHelper.initialize();
     }
 
+    @Test
+    public void testOnCreate_passwordNormalFlow_expectCheckEmailFlowStarted() {
+        EmailActivity emailActivity = createActivity(EmailAuthProvider.PROVIDER_ID);
+        emailActivity.getSupportFragmentManager().findFragmentByTag(CheckEmailFragment.TAG);
+    }
+
+    @Test
+    public void testOnCreate_emailLinkNormalFlow_expectCheckEmailFlowStarted() {
+        EmailActivity emailActivity = createActivity(AuthUI.EMAIL_LINK_PROVIDER);
+        emailActivity.getSupportFragmentManager().findFragmentByTag(CheckEmailFragment.TAG);
+    }
+
+    @Test
+    public void testOnCreate_emailLinkLinkingFlow_expectSendEmailLinkFlowStarted() {
+        EmailActivity emailActivity = createActivity(AuthUI.EMAIL_LINK_PROVIDER, true);
+
+        EmailLinkFragment fragment = (EmailLinkFragment) emailActivity
+                .getSupportFragmentManager().findFragmentByTag(EmailLinkFragment.TAG);
+        assertThat(fragment).isNotNull();
+
+        EmailLinkPersistenceManager persistenceManager = EmailLinkPersistenceManager.getInstance();
+        IdpResponse response = persistenceManager.retrieveIdpResponseForLinking
+                (RuntimeEnvironment.application);
+
+        assertThat(response.getProviderType()).isEqualTo(GoogleAuthProvider.PROVIDER_ID);
+        assertThat(response.getEmail()).isEqualTo(EMAIL);
+        assertThat(response.getIdpToken()).isEqualTo(ID_TOKEN);
+        assertThat(response.getIdpSecret()).isEqualTo(SECRET);
+    }
+
+    // @Test TODO(lsirac): uncomment after figuring out why this no longer works
+    public void testOnTroubleSigningIn_expectTroubleSigningInFragment() {
+        EmailActivity emailActivity = createActivity(AuthUI.EMAIL_LINK_PROVIDER);
+
+        emailActivity.onTroubleSigningIn(EMAIL);
+
+        TroubleSigningInFragment fragment = (TroubleSigningInFragment) emailActivity
+                .getSupportFragmentManager().findFragmentByTag(TroubleSigningInFragment.TAG);
+        assertThat(fragment).isNotNull();
+    }
+
+    @Test
+    public void testOnClickResendEmail_expectSendEmailLinkFlowStarted() {
+        EmailActivity emailActivity = createActivity(AuthUI.EMAIL_LINK_PROVIDER);
+
+        emailActivity.onClickResendEmail(EMAIL);
+
+        EmailLinkFragment fragment = (EmailLinkFragment) emailActivity
+                .getSupportFragmentManager().findFragmentByTag(EmailLinkFragment.TAG);
+        assertThat(fragment).isNotNull();
+    }
+
+
     @Test
     public void testSignUpButton_validatesFields() {
-        EmailActivity emailActivity = createActivity();
+
+        EmailActivity emailActivity = createActivity(EmailAuthProvider.PROVIDER_ID);
 
         // Trigger RegisterEmailFragment (bypass check email)
         emailActivity.onNewUser(
@@ -81,4 +134,34 @@ public void testSignUpButton_validatesFields() {
                 ),
                 passwordLayout.getError().toString());
     }
+
+
+    private EmailActivity createActivity(String providerId) {
+        return createActivity(providerId, false);
+    }
+
+    private EmailActivity createActivity(String providerId, boolean emailLinkLinkingFlow) {
+        Intent startIntent = EmailActivity.createIntent(
+                RuntimeEnvironment.application,
+                TestHelper.getFlowParameters(Collections.singletonList(providerId)));
+
+        if (emailLinkLinkingFlow) {
+            startIntent.putExtra(ExtraConstants.EMAIL, EMAIL);
+            startIntent.putExtra(ExtraConstants.IDP_RESPONSE, buildGoogleIdpResponse());
+        }
+
+        return Robolectric.buildActivity(EmailActivity.class, startIntent)
+                .create()
+                .start()
+                .visible()
+                .get();
+    }
+
+    private IdpResponse buildGoogleIdpResponse() {
+        return new IdpResponse.Builder(
+                new User.Builder(GoogleAuthProvider.PROVIDER_ID, EMAIL).build())
+                .setToken(ID_TOKEN)
+                .setSecret(SECRET)
+                .build();
+    }
 }
diff --git a/auth/src/test/java/com/firebase/ui/auth/viewmodel/EmailLinkSendEmailHandlerTest.java b/auth/src/test/java/com/firebase/ui/auth/viewmodel/EmailLinkSendEmailHandlerTest.java
new file mode 100644
index 000000000..7a92ab13d
--- /dev/null
+++ b/auth/src/test/java/com/firebase/ui/auth/viewmodel/EmailLinkSendEmailHandlerTest.java
@@ -0,0 +1,114 @@
+package com.firebase.ui.auth.viewmodel;
+
+import android.arch.lifecycle.Observer;
+
+import com.firebase.ui.auth.testhelpers.ResourceMatchers;
+import com.firebase.ui.auth.util.data.EmailLinkPersistenceManager;
+import com.firebase.ui.auth.data.model.FlowParameters;
+import com.firebase.ui.auth.data.model.Resource;
+import com.firebase.ui.auth.data.model.State;
+import com.firebase.ui.auth.testhelpers.AutoCompleteTask;
+import com.firebase.ui.auth.testhelpers.TestConstants;
+import com.firebase.ui.auth.testhelpers.TestHelper;
+import com.firebase.ui.auth.viewmodel.email.EmailLinkSendEmailHandler;
+import com.google.firebase.auth.ActionCodeSettings;
+import com.google.firebase.auth.FirebaseAuth;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.InOrder;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+
+import java.util.ArrayList;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.argThat;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+/**
+ * Unit tests for {@link EmailLinkSendEmailHandler}.
+ */
+@RunWith(RobolectricTestRunner.class)
+public class EmailLinkSendEmailHandlerTest {
+
+    private static String URL = "url";
+
+    private EmailLinkPersistenceManager mPersistenceManager;
+    private EmailLinkSendEmailHandler mHandler;
+
+    @Mock private FirebaseAuth mMockAuth;
+    @Mock private Observer<Resource<String>> mResponseObserver;
+
+    @Before
+    public void setUp() {
+        TestHelper.initialize();
+        MockitoAnnotations.initMocks(this);
+
+        mHandler = new EmailLinkSendEmailHandler(RuntimeEnvironment.application);
+        FlowParameters testParams = TestHelper.getFlowParameters(new ArrayList<String>());
+
+        mHandler.initializeForTesting(testParams, mMockAuth, null, null);
+        mPersistenceManager = EmailLinkPersistenceManager.getInstance();
+    }
+
+    @Test
+    @SuppressWarnings("unchecked")
+    public void testSendSignInLinkToEmail_expectSuccess() {
+        mHandler.getOperation().observeForever(mResponseObserver);
+
+        ActionCodeSettings actionCodeSettings = ActionCodeSettings.newBuilder().setUrl(URL).build();
+        when(mMockAuth.sendSignInLinkToEmail(any(String.class), any(ActionCodeSettings.class)))
+                .thenReturn(AutoCompleteTask.<Void>forSuccess(null));
+
+        mHandler.sendSignInLinkToEmail(TestConstants.EMAIL, actionCodeSettings);
+
+        verify(mMockAuth).sendSignInLinkToEmail(eq(TestConstants.EMAIL), eq(actionCodeSettings));
+
+        String email = mPersistenceManager.retrieveEmailForLink(RuntimeEnvironment.application);
+        assertThat(email).isNotNull();
+        assertThat(email).isEqualTo(TestConstants.EMAIL);
+
+        ArgumentCaptor<Resource<String>> captor = ArgumentCaptor.forClass(Resource.class);
+        InOrder inOrder = inOrder(mResponseObserver);
+        inOrder.verify(mResponseObserver)
+                .onChanged(argThat(ResourceMatchers.<String>isLoading()));
+
+        inOrder.verify(mResponseObserver).onChanged(captor.capture());
+
+        assertThat(captor.getValue().getState()).isEqualTo(State.SUCCESS);
+        assertThat(captor.getValue().getValue()).isEqualTo(TestConstants.EMAIL);
+    }
+
+    @Test
+    @SuppressWarnings("unchecked")
+    public void testSendSignInLinkToEmail_expectFailure() {
+        mHandler.getOperation().observeForever(mResponseObserver);
+
+        ActionCodeSettings actionCodeSettings = ActionCodeSettings.newBuilder().setUrl(URL).build();
+        when(mMockAuth.sendSignInLinkToEmail(any(String.class), any(ActionCodeSettings.class)))
+                .thenReturn(AutoCompleteTask.<Void>forFailure(new Exception()));
+
+        mHandler.sendSignInLinkToEmail(TestConstants.EMAIL, actionCodeSettings);
+
+        verify(mMockAuth).sendSignInLinkToEmail(eq(TestConstants.EMAIL), eq(actionCodeSettings));
+
+
+        ArgumentCaptor<Resource<String>> captor = ArgumentCaptor.forClass(Resource.class);
+        InOrder inOrder = inOrder(mResponseObserver);
+        inOrder.verify(mResponseObserver)
+                .onChanged(argThat(ResourceMatchers.<String>isLoading()));
+        inOrder.verify(mResponseObserver).onChanged(captor.capture());
+
+        assertThat(captor.getValue().getState()).isEqualTo(State.FAILURE);
+        assertThat(captor.getValue().getException()).isNotNull();
+    }
+}
diff --git a/auth/src/test/java/com/firebase/ui/auth/viewmodel/EmailLinkSignInHandlerTest.java b/auth/src/test/java/com/firebase/ui/auth/viewmodel/EmailLinkSignInHandlerTest.java
new file mode 100644
index 000000000..1a28d94e7
--- /dev/null
+++ b/auth/src/test/java/com/firebase/ui/auth/viewmodel/EmailLinkSignInHandlerTest.java
@@ -0,0 +1,518 @@
+package com.firebase.ui.auth.viewmodel;
+
+import android.arch.lifecycle.Observer;
+
+import com.firebase.ui.auth.AuthUI;
+import com.firebase.ui.auth.ErrorCodes;
+import com.firebase.ui.auth.FirebaseAuthAnonymousUpgradeException;
+import com.firebase.ui.auth.FirebaseUiException;
+import com.firebase.ui.auth.IdpResponse;
+import com.firebase.ui.auth.data.model.FlowParameters;
+import com.firebase.ui.auth.data.model.Resource;
+import com.firebase.ui.auth.data.model.State;
+import com.firebase.ui.auth.data.model.User;
+import com.firebase.ui.auth.testhelpers.AutoCompleteTask;
+import com.firebase.ui.auth.testhelpers.AutoContinueTask;
+import com.firebase.ui.auth.testhelpers.ResourceMatchers;
+import com.firebase.ui.auth.testhelpers.TestConstants;
+import com.firebase.ui.auth.testhelpers.TestHelper;
+import com.firebase.ui.auth.util.data.AuthOperationManager;
+import com.firebase.ui.auth.util.data.EmailLinkPersistenceManager;
+import com.firebase.ui.auth.viewmodel.email.EmailLinkSignInHandler;
+import com.google.firebase.auth.ActionCodeResult;
+import com.google.firebase.auth.AdditionalUserInfo;
+import com.google.firebase.auth.AuthCredential;
+import com.google.firebase.auth.AuthResult;
+import com.google.firebase.auth.EmailAuthCredential;
+import com.google.firebase.auth.EmailAuthProvider;
+import com.google.firebase.auth.FacebookAuthCredential;
+import com.google.firebase.auth.FacebookAuthProvider;
+import com.google.firebase.auth.FirebaseAuth;
+import com.google.firebase.auth.FirebaseAuthUserCollisionException;
+import com.google.firebase.auth.FirebaseUser;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.InOrder;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+
+import java.util.ArrayList;
+import java.util.Collections;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.argThat;
+import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+/**
+ * Unit tests for {@link EmailLinkSignInHandler}.
+ */
+@RunWith(RobolectricTestRunner.class)
+public class EmailLinkSignInHandlerTest {
+
+    private static final String EMAIL_LINK = "?oobCode=oobCode&mode=signIn";
+
+    private EmailLinkSignInHandler mHandler;
+    private EmailLinkPersistenceManager mPersistenceManager;
+
+    @Mock private FirebaseAuth mMockAuth;
+    @Mock private FirebaseAuth mScratchMockAuth;
+    @Mock private FirebaseUser mMockAnonUser;
+    @Mock private Observer<Resource<IdpResponse>> mResponseObserver;
+    @Mock private AuthResult mMockAuthResult;
+    @Mock private AdditionalUserInfo mockAdditionalUserInfo;
+
+    @Mock private ActionCodeResult mMockActionCodeResult;
+
+    @Before
+    public void setUp() {
+        TestHelper.initialize();
+        MockitoAnnotations.initMocks(this);
+
+        mHandler = new EmailLinkSignInHandler(RuntimeEnvironment.application);
+        FlowParameters testParams = TestHelper.getFlowParameters(new ArrayList<String>());
+        testParams.emailLink = EMAIL_LINK;
+        mHandler.initializeForTesting(testParams, mMockAuth, null, null);
+        mPersistenceManager = EmailLinkPersistenceManager.getInstance();
+
+        FirebaseUser user = TestHelper.getMockFirebaseUser();
+        when(mMockAuthResult.getUser()).thenReturn(user);
+        when(mMockAuthResult.getAdditionalUserInfo()).thenReturn(mockAdditionalUserInfo);
+        when(mockAdditionalUserInfo.isNewUser()).thenReturn(false);
+    }
+
+    @Test
+    @SuppressWarnings("all")
+    public void testStartSignIn_wrongDeviceFlow() {
+        mHandler.getOperation().observeForever(mResponseObserver);
+        when(mMockAuth.isSignInWithEmailLink(any(String.class))).thenReturn(true);
+        when(mMockAuth.checkActionCode(any(String.class))).thenReturn(AutoCompleteTask.forSuccess
+                (mMockActionCodeResult));
+
+        mHandler.startSignIn();
+
+        ArgumentCaptor<Resource<IdpResponse>> captor =
+                ArgumentCaptor.forClass(Resource.class);
+
+        InOrder inOrder = inOrder(mResponseObserver);
+        inOrder.verify(mResponseObserver)
+                .onChanged(argThat(ResourceMatchers.<IdpResponse>isLoading()));
+        inOrder.verify(mResponseObserver).onChanged(captor.capture());
+
+        FirebaseUiException exception = (FirebaseUiException) captor.getValue().getException();
+        assertThat(exception).isNotNull();
+        assertThat(exception.getErrorCode()).isEqualTo(ErrorCodes
+                .EMAIL_LINK_WRONG_DEVICE_ERROR);
+    }
+
+    @Test
+    @SuppressWarnings("all")
+    public void testStartSignIn_normalFlow() {
+        mHandler.getOperation().observeForever(mResponseObserver);
+        when(mMockAuth.isSignInWithEmailLink(any(String.class))).thenReturn(true);
+
+        mPersistenceManager.saveEmailForLink(RuntimeEnvironment.application, TestConstants.EMAIL);
+
+        when(mMockAuth.signInWithCredential(any(AuthCredential.class))).thenReturn
+                (AutoCompleteTask.forSuccess(mMockAuthResult));
+
+        mHandler.startSignIn();
+
+        ArgumentCaptor<Resource<IdpResponse>> captor =
+                ArgumentCaptor.forClass(Resource.class);
+
+        InOrder inOrder = inOrder(mResponseObserver);
+        inOrder.verify(mResponseObserver)
+                .onChanged(argThat(ResourceMatchers.<IdpResponse>isLoading()));
+        inOrder.verify(mResponseObserver).onChanged(captor.capture());
+
+        IdpResponse response = captor.getValue().getValue();
+
+        assertThat(response.getUser().getProviderId()).isEqualTo(AuthUI.EMAIL_LINK_PROVIDER);
+        assertThat(response.getUser().getEmail()).isEqualTo(mMockAuthResult.getUser()
+                .getEmail());
+        assertThat(response.getUser().getName()).isEqualTo(mMockAuthResult.getUser()
+                .getDisplayName());
+        assertThat(response.getUser().getPhotoUri()).isEqualTo(mMockAuthResult.getUser()
+                .getPhotoUrl());
+
+        assertThat(mPersistenceManager.retrieveEmailForLink(RuntimeEnvironment.application))
+                .isNull();
+    }
+
+    @Test
+    @SuppressWarnings("all")
+    public void testStartSignIn_normalFlowWithAnonymousUpgrade_expectSuccessfulMerge() {
+        mHandler.getOperation().observeForever(mResponseObserver);
+        setupAnonymousUpgrade();
+        when(mMockAuth.isSignInWithEmailLink(any(String.class))).thenReturn(true);
+
+        mPersistenceManager.saveEmailForLink(RuntimeEnvironment.application, TestConstants.EMAIL);
+
+        when(mMockAuth.getCurrentUser().linkWithCredential(any(AuthCredential.class)))
+                .thenReturn(new AutoContinueTask<>(mMockAuthResult,
+                        mMockAuthResult,
+                        true,
+                        null));
+
+        mHandler.startSignIn();
+
+        ArgumentCaptor<Resource<IdpResponse>> captor =
+                ArgumentCaptor.forClass(Resource.class);
+
+        InOrder inOrder = inOrder(mResponseObserver);
+
+        inOrder.verify(mResponseObserver)
+                .onChanged(argThat(ResourceMatchers.<IdpResponse>isLoading()));
+        inOrder.verify(mResponseObserver).onChanged(captor.capture());
+
+        IdpResponse response = captor.getValue().getValue();
+
+        assertThat(response.getUser().getProviderId()).isEqualTo(AuthUI.EMAIL_LINK_PROVIDER);
+        assertThat(response.getUser().getEmail()).isEqualTo(mMockAuthResult.getUser()
+                .getEmail());
+        assertThat(response.getUser().getName()).isEqualTo(mMockAuthResult.getUser()
+                .getDisplayName());
+        assertThat(response.getUser().getPhotoUri()).isEqualTo(mMockAuthResult.getUser()
+                .getPhotoUrl());
+
+        assertThat(mPersistenceManager.retrieveEmailForLink(RuntimeEnvironment.application))
+                .isNull();
+    }
+
+    @Test
+    @SuppressWarnings("all")
+    public void testStartSignIn_normalFlowWithAnonymousUpgrade_expectMergeFailure() {
+        mHandler.getOperation().observeForever(mResponseObserver);
+        setupAnonymousUpgrade();
+        when(mMockAuth.isSignInWithEmailLink(any(String.class))).thenReturn(true);
+
+        mPersistenceManager.saveEmailForLink(RuntimeEnvironment.application, TestConstants.EMAIL);
+
+        when(mMockAuth.getCurrentUser().linkWithCredential(any(AuthCredential.class)))
+                .thenReturn(AutoCompleteTask.<AuthResult>forFailure(
+                        new FirebaseAuthUserCollisionException("foo", "bar")));
+
+        mHandler.startSignIn();
+
+        ArgumentCaptor<Resource<IdpResponse>> captor =
+                ArgumentCaptor.forClass(Resource.class);
+
+        InOrder inOrder = inOrder(mResponseObserver);
+
+        inOrder.verify(mResponseObserver)
+                .onChanged(argThat(ResourceMatchers.<IdpResponse>isLoading()));
+        inOrder.verify(mResponseObserver).onChanged(captor.capture());
+
+
+        assertThat(captor.getValue().getException()).isNotNull();
+        FirebaseAuthAnonymousUpgradeException mergeException =
+                (FirebaseAuthAnonymousUpgradeException) captor.getValue().getException();
+        assertThat(mergeException.getResponse().getCredentialForLinking()).isNotNull();
+        assertThat(mPersistenceManager.retrieveEmailForLink(RuntimeEnvironment.application))
+                .isNull();
+    }
+
+    @Test
+    @SuppressWarnings("all")
+    public void testStartSignIn_linkingFlow_expectSuccessfulLink() {
+        mHandler.getOperation().observeForever(mResponseObserver);
+        when(mMockAuth.isSignInWithEmailLink(any(String.class))).thenReturn(true);
+
+        mPersistenceManager.saveEmailForLink(RuntimeEnvironment.application, TestConstants.EMAIL);
+        mPersistenceManager.saveIdpResponseForLinking(RuntimeEnvironment.application,
+                buildFacebookIdpResponse());
+
+
+        when(mMockAuth.signInWithCredential(any(AuthCredential.class))).thenReturn
+                (AutoCompleteTask.forSuccess(mMockAuthResult));
+
+        // Mock linking with Facebook to always work
+        when(mMockAuthResult.getUser().linkWithCredential(any(FacebookAuthCredential
+                .class)))
+                .thenReturn(new AutoContinueTask<>(mMockAuthResult,
+                        mMockAuthResult,
+                        true,
+                        null));
+
+        mHandler.startSignIn();
+
+        // Validate regular sign in
+        ArgumentCaptor<EmailAuthCredential> credentialCaptor
+                = ArgumentCaptor.forClass(EmailAuthCredential.class);
+        verify(mMockAuth).signInWithCredential(credentialCaptor.capture());
+
+        assertThat(credentialCaptor.getValue().getEmail()).isEqualTo(TestConstants.EMAIL);
+        assertThat(credentialCaptor.getValue().getSignInMethod()).isEqualTo(EmailAuthProvider
+                .EMAIL_LINK_SIGN_IN_METHOD);
+
+        // Validate linking was called
+        verify(mMockAuthResult.getUser()).linkWithCredential(any(FacebookAuthCredential
+                .class));
+
+        // Validate that the data was cleared
+        assertThat(mPersistenceManager.retrieveEmailForLink(RuntimeEnvironment.application))
+                .isNull();
+        assertThat(mPersistenceManager.retrieveIdpResponseForLinking(RuntimeEnvironment
+                .application))
+                .isNull();
+
+
+        // Validate IdpResponse
+        ArgumentCaptor<Resource<IdpResponse>> captor =
+                ArgumentCaptor.forClass(Resource.class);
+
+        InOrder inOrder = inOrder(mResponseObserver);
+
+        inOrder.verify(mResponseObserver)
+                .onChanged(argThat(ResourceMatchers.<IdpResponse>isLoading()));
+        inOrder.verify(mResponseObserver).onChanged(captor.capture());
+
+
+        IdpResponse response = captor.getValue().getValue();
+
+        assertThat(captor.getValue().getState()).isEqualTo(State.SUCCESS);
+
+        assertThat(response.getUser().getProviderId()).isEqualTo(AuthUI.EMAIL_LINK_PROVIDER);
+        assertThat(response.getUser().getEmail()).isEqualTo(mMockAuthResult.getUser()
+                .getEmail());
+        assertThat(response.getUser().getName()).isEqualTo(mMockAuthResult.getUser()
+                .getDisplayName());
+        assertThat(response.getUser().getPhotoUri()).isEqualTo(mMockAuthResult.getUser()
+                .getPhotoUrl());
+    }
+
+    @Test
+    @SuppressWarnings("all")
+    public void testStartSignIn_linkingFlow_expectUserCollisionException() {
+        mHandler.getOperation().observeForever(mResponseObserver);
+        when(mMockAuth.isSignInWithEmailLink(any(String.class))).thenReturn(true);
+
+        mPersistenceManager.saveEmailForLink(RuntimeEnvironment.application, TestConstants.EMAIL);
+        mPersistenceManager.saveIdpResponseForLinking(RuntimeEnvironment.application,
+                buildFacebookIdpResponse());
+
+
+        when(mMockAuth.signInWithCredential(any(AuthCredential.class))).thenReturn
+                (AutoCompleteTask.forSuccess(mMockAuthResult));
+
+        // Mock linking with Facebook to always work
+        when(mMockAuthResult.getUser().linkWithCredential(any(FacebookAuthCredential
+                .class)))
+                .thenReturn(AutoCompleteTask.<AuthResult>forFailure(
+                        new FirebaseAuthUserCollisionException("foo", "bar")));
+
+        mHandler.startSignIn();
+
+        ArgumentCaptor<Resource<IdpResponse>> captor =
+                ArgumentCaptor.forClass(Resource.class);
+
+        InOrder inOrder = inOrder(mResponseObserver);
+
+        inOrder.verify(mResponseObserver)
+                .onChanged(argThat(ResourceMatchers.<IdpResponse>isLoading()));
+        inOrder.verify(mResponseObserver).onChanged(captor.capture());
+
+
+        assertThat(captor.getValue().getException()).isNotNull();
+        FirebaseAuthUserCollisionException collisionException =
+                (FirebaseAuthUserCollisionException) captor.getValue().getException();
+        assertThat(mPersistenceManager.retrieveEmailForLink(RuntimeEnvironment.application))
+                .isNull();
+    }
+
+
+    @Test
+    @SuppressWarnings("all")
+    public void testStartSignIn_linkingFlowWithAnonymousUpgradeEnabled_expectMergeFailure() {
+        mHandler.getOperation().observeForever(mResponseObserver);
+        setupAnonymousUpgrade();
+        when(mMockAuth.isSignInWithEmailLink(any(String.class))).thenReturn(true);
+
+        mPersistenceManager.saveEmailForLink(RuntimeEnvironment.application, TestConstants.EMAIL);
+        mPersistenceManager.saveIdpResponseForLinking(RuntimeEnvironment.application,
+                buildFacebookIdpResponse());
+
+        // Need to control FirebaseAuth's return values
+        AuthOperationManager authOperationManager = AuthOperationManager.getInstance();
+        authOperationManager.mScratchAuth = mScratchMockAuth;
+
+        when(mScratchMockAuth.signInWithCredential(any(AuthCredential.class)))
+                .thenReturn(AutoCompleteTask.forSuccess(mMockAuthResult));
+
+        // Mock linking with Facebook to always work
+        when(mMockAuthResult.getUser().linkWithCredential(any(AuthCredential
+                .class)))
+                .thenReturn(new AutoContinueTask<>(mMockAuthResult,
+                        mMockAuthResult,
+                        true,
+                        null));
+
+        mHandler.startSignIn();
+
+        // Validate regular sign in
+        ArgumentCaptor<EmailAuthCredential> credentialCaptor
+                = ArgumentCaptor.forClass(EmailAuthCredential.class);
+        verify(mScratchMockAuth).signInWithCredential(credentialCaptor.capture());
+
+        assertThat(credentialCaptor.getValue().getEmail()).isEqualTo(TestConstants.EMAIL);
+        assertThat(credentialCaptor.getValue().getSignInMethod()).isEqualTo(EmailAuthProvider
+                .EMAIL_LINK_SIGN_IN_METHOD);
+
+        // Validate linking was called
+        verify(mMockAuthResult.getUser()).linkWithCredential(any(FacebookAuthCredential
+                .class));
+
+        // Validate that the data was cleared
+        assertThat(mPersistenceManager.retrieveEmailForLink(RuntimeEnvironment.application))
+                .isNull();
+        assertThat(mPersistenceManager.retrieveIdpResponseForLinking(RuntimeEnvironment
+                .application))
+                .isNull();
+
+
+        // Validate IdpResponse
+        ArgumentCaptor<Resource<IdpResponse>> captor =
+                ArgumentCaptor.forClass(Resource.class);
+
+        InOrder inOrder = inOrder(mResponseObserver);
+
+        inOrder.verify(mResponseObserver)
+                .onChanged(argThat(ResourceMatchers.<IdpResponse>isLoading()));
+        inOrder.verify(mResponseObserver).onChanged(captor.capture());
+
+
+        FirebaseAuthAnonymousUpgradeException mergeException =
+                ((FirebaseAuthAnonymousUpgradeException) captor.getValue().getException());
+
+        IdpResponse response = mergeException.getResponse();
+        assertThat(response.getCredentialForLinking()).isNotNull();
+        assertThat(response.getCredentialForLinking().getProvider()).isEqualTo
+                (FacebookAuthProvider.PROVIDER_ID);
+    }
+
+    @Test
+    @SuppressWarnings("all")
+    public void testStartSignIn_linkingFlowWithAnonymousUpgradeEnabled_failedSignInPropagated() {
+        mHandler.getOperation().observeForever(mResponseObserver);
+        setupAnonymousUpgrade();
+        when(mMockAuth.isSignInWithEmailLink(any(String.class))).thenReturn(true);
+
+        mPersistenceManager.saveEmailForLink(RuntimeEnvironment.application, TestConstants.EMAIL);
+        mPersistenceManager.saveIdpResponseForLinking(RuntimeEnvironment.application,
+                buildFacebookIdpResponse());
+
+        // Need to control FirebaseAuth's return values
+        AuthOperationManager authOperationManager = AuthOperationManager.getInstance();
+        authOperationManager.mScratchAuth = mScratchMockAuth;
+
+        when(mScratchMockAuth.signInWithCredential(any(AuthCredential.class)))
+                .thenReturn(AutoContinueTask.<AuthResult>forFailure(new Exception("FAILED")));
+
+        mHandler.startSignIn();
+
+        // Verify sign in was called
+        verify(mScratchMockAuth).signInWithCredential(any(AuthCredential.class));
+
+        // Validate that the data was cleared
+        assertThat(mPersistenceManager.retrieveEmailForLink(RuntimeEnvironment.application))
+                .isNull();
+        assertThat(mPersistenceManager.retrieveIdpResponseForLinking(RuntimeEnvironment
+                .application))
+                .isNull();
+
+        // Validate failure
+        ArgumentCaptor<Resource<IdpResponse>> captor =
+                ArgumentCaptor.forClass(Resource.class);
+
+        InOrder inOrder = inOrder(mResponseObserver);
+
+        inOrder.verify(mResponseObserver)
+                .onChanged(argThat(ResourceMatchers.<IdpResponse>isLoading()));
+        inOrder.verify(mResponseObserver).onChanged(captor.capture());
+
+        assertThat(captor.getValue().getException()).isNotNull();
+    }
+
+    @Test
+    @SuppressWarnings("all")
+    public void testStartSignIn_linkingFlowWithAnonymousUpgradeEnabled_failedLinkPropagated() {
+        mHandler.getOperation().observeForever(mResponseObserver);
+        setupAnonymousUpgrade();
+        when(mMockAuth.isSignInWithEmailLink(any(String.class))).thenReturn(true);
+
+        mPersistenceManager.saveEmailForLink(RuntimeEnvironment.application, TestConstants.EMAIL);
+        mPersistenceManager.saveIdpResponseForLinking(RuntimeEnvironment.application,
+                buildFacebookIdpResponse());
+
+        // Need to control FirebaseAuth's return values
+        AuthOperationManager authOperationManager = AuthOperationManager.getInstance();
+        authOperationManager.mScratchAuth = mScratchMockAuth;
+
+        when(mScratchMockAuth.signInWithCredential(any(AuthCredential.class)))
+                .thenReturn(AutoCompleteTask.forSuccess(mMockAuthResult));
+
+        // Mock linking with Facebook to always work
+        when(mMockAuthResult.getUser().linkWithCredential(any(AuthCredential
+                .class)))
+                .thenReturn(AutoContinueTask.<AuthResult>forFailure(new Exception("FAILED")));
+
+        mHandler.startSignIn();
+
+        // Verify sign in was called
+        verify(mScratchMockAuth).signInWithCredential(any(AuthCredential.class));
+
+        // Validate linking was called
+        verify(mMockAuthResult.getUser()).linkWithCredential(any(FacebookAuthCredential
+                .class));
+
+        // Validate that the data was cleared
+        assertThat(mPersistenceManager.retrieveEmailForLink(RuntimeEnvironment.application))
+                .isNull();
+        assertThat(mPersistenceManager.retrieveIdpResponseForLinking(RuntimeEnvironment
+                .application))
+                .isNull();
+
+        // Validate failure
+        ArgumentCaptor<Resource<IdpResponse>> captor =
+                ArgumentCaptor.forClass(Resource.class);
+
+        InOrder inOrder = inOrder(mResponseObserver);
+
+        inOrder.verify(mResponseObserver)
+                .onChanged(argThat(ResourceMatchers.<IdpResponse>isLoading()));
+        inOrder.verify(mResponseObserver).onChanged(captor.capture());
+
+        assertThat(captor.getValue().getException()).isNotNull();
+    }
+
+    private IdpResponse buildFacebookIdpResponse() {
+        User user = new User.Builder(FacebookAuthProvider.PROVIDER_ID, TestConstants.EMAIL)
+                .build();
+
+        return new IdpResponse.Builder(user)
+                .setToken(TestConstants.TOKEN)
+                .setSecret(TestConstants.SECRET)
+                .build();
+    }
+
+    private void setupAnonymousUpgrade() {
+        // enableAnonymousUpgrade must be set to true
+        FlowParameters testParams = TestHelper.getFlowParameters(Collections.singletonList(
+                EmailAuthProvider.PROVIDER_ID), /* enableAnonymousUpgrade */ true);
+        mHandler.initializeForTesting(testParams, mMockAuth, null, null);
+
+        // Mock isAnonymous() to return true so canUpgradeAnonymous will return true
+        when(mMockAnonUser.isAnonymous()).thenReturn(true);
+        when(mMockAuth.getCurrentUser()).thenReturn(mMockAnonUser);
+        testParams.emailLink = EMAIL_LINK;
+    }
+
+}
diff --git a/build.gradle.kts b/build.gradle.kts
index 172d00e39..240afaa45 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -102,7 +102,8 @@ fun Project.configureAndroid() {
                     "IconExpectedSize",
                     "InvalidPackage", // Firestore uses GRPC which makes lint mad
                     "NewerVersionAvailable", "GradleDependency", // For reproducible builds
-                    "SelectableText", "SyntheticAccessor" // We almost never care about this
+                    "SelectableText", "SyntheticAccessor", // We almost never care about this
+                    "MissingTranslation" // TODO remove in future PR
             )
 
             isCheckAllWarnings = true