diff --git a/build.gradle b/build.gradle
index 9b0927d..5b94bb3 100644
--- a/build.gradle
+++ b/build.gradle
@@ -6,7 +6,7 @@ buildscript {
         google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.5.0-alpha01'
+        classpath 'com.android.tools.build:gradle:3.5.0'
 
         // For the library uploading to the Bintray
         classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.7.1'
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 367bbb2..3ebf4c7 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.1-milestone-1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.4-all.zip
diff --git a/library/build.gradle b/library/build.gradle
index 415d153..fb0f944 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -8,6 +8,7 @@ targetCompatibility = JavaVersion.VERSION_1_7
 dependencies {
     compileOnly project(':stub-android')
     compileOnly 'com.google.android:android:4.1.1.4'
+    implementation "org.jetbrains:annotations:16.0.3"
 }
 
 ext {
@@ -16,7 +17,7 @@ ext {
     bintrayName = 'cicerone'
     publishedGroupId = 'ru.terrakok.cicerone'
     artifact = 'cicerone'
-    libraryVersion = '5.0.0'
+    libraryVersion = '5.1.0'
     gitUrl = 'https://github.com/terrakok/Cicerone'
     allLicenses = ['MIT']
 }
@@ -24,7 +25,7 @@ ext {
 // Configuration of the library uploading to the Bintray
 // Note: Call 'bintrayUpload' task (it will execute 'install' task first)
 // I try to include as little properties as possible in these files
-project.archivesBaseName ='cicerone' // to fix that project name different from artifact name
+project.archivesBaseName = 'cicerone' // to fix that project name different from artifact name
 apply from: 'androidmaven.gradle'
 apply from: 'bintray.gradle'
 
diff --git a/library/src/main/java/ru/terrakok/cicerone/BaseRouter.java b/library/src/main/java/ru/terrakok/cicerone/BaseRouter.java
index f34c394..45cad1a 100644
--- a/library/src/main/java/ru/terrakok/cicerone/BaseRouter.java
+++ b/library/src/main/java/ru/terrakok/cicerone/BaseRouter.java
@@ -4,6 +4,8 @@
 
 package ru.terrakok.cicerone;
 
+import org.jetbrains.annotations.NotNull;
+
 import ru.terrakok.cicerone.commands.Command;
 
 /**
@@ -17,6 +19,7 @@ public BaseRouter() {
         this.commandBuffer = new CommandBuffer();
     }
 
+    @NotNull
     CommandBuffer getCommandBuffer() {
         return commandBuffer;
     }
@@ -26,7 +29,7 @@ CommandBuffer getCommandBuffer() {
      *
      * @param commands navigation command array to execute
      */
-    protected void executeCommands(Command... commands) {
+    protected void executeCommands(@NotNull Command... commands) {
         commandBuffer.executeCommands(commands);
     }
 }
diff --git a/library/src/main/java/ru/terrakok/cicerone/Cicerone.java b/library/src/main/java/ru/terrakok/cicerone/Cicerone.java
index 09ef339..c2cf8e3 100644
--- a/library/src/main/java/ru/terrakok/cicerone/Cicerone.java
+++ b/library/src/main/java/ru/terrakok/cicerone/Cicerone.java
@@ -4,6 +4,8 @@
 
 package ru.terrakok.cicerone;
 
+import org.jetbrains.annotations.NotNull;
+
 /**
  * Cicerone is the holder for other library components.
  * To use it, instantiate it using one of the {@link #create()} methods.
@@ -15,14 +17,16 @@
 public class Cicerone<T extends BaseRouter> {
     private T router;
 
-    private Cicerone(T router) {
+    private Cicerone(@NotNull T router) {
         this.router = router;
     }
 
+    @NotNull
     public NavigatorHolder getNavigatorHolder() {
         return router.getCommandBuffer();
     }
 
+    @NotNull
     public T getRouter() {
         return router;
     }
@@ -30,6 +34,7 @@ public T getRouter() {
     /**
      * Creates the Cicerone instance with the default {@link Router router}
      */
+    @NotNull
     public static Cicerone<Router> create() {
         return create(new Router());
     }
@@ -38,7 +43,8 @@ public static Cicerone<Router> create() {
      * Creates the Cicerone instance with the custom router.
      * @param customRouter the custom router extending {@link BaseRouter}
      */
-    public static <T extends BaseRouter> Cicerone<T> create(T customRouter) {
+    @NotNull
+    public static <T extends BaseRouter> Cicerone<T> create(@NotNull T customRouter) {
         return new Cicerone<>(customRouter);
     }
 }
diff --git a/library/src/main/java/ru/terrakok/cicerone/CommandBuffer.java b/library/src/main/java/ru/terrakok/cicerone/CommandBuffer.java
index 4e0645b..7d1ae67 100644
--- a/library/src/main/java/ru/terrakok/cicerone/CommandBuffer.java
+++ b/library/src/main/java/ru/terrakok/cicerone/CommandBuffer.java
@@ -4,6 +4,9 @@
 
 package ru.terrakok.cicerone;
 
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
 import java.util.LinkedList;
 import java.util.Queue;
 
@@ -18,7 +21,7 @@ class CommandBuffer implements NavigatorHolder {
     private Queue<Command[]> pendingCommands = new LinkedList<>();
 
     @Override
-    public void setNavigator(Navigator navigator) {
+    public void setNavigator(@Nullable Navigator navigator) {
         this.navigator = navigator;
         while (!pendingCommands.isEmpty()) {
             if (navigator != null) {
@@ -37,7 +40,7 @@ public void removeNavigator() {
      * Else puts it to the pending commands queue to pass it later.
      * @param commands navigation command array
      */
-    void executeCommands(Command[] commands) {
+    void executeCommands(@NotNull Command[] commands) {
         if (navigator != null) {
             navigator.applyCommands(commands);
         } else {
diff --git a/library/src/main/java/ru/terrakok/cicerone/Navigator.java b/library/src/main/java/ru/terrakok/cicerone/Navigator.java
index de44ada..36d6975 100644
--- a/library/src/main/java/ru/terrakok/cicerone/Navigator.java
+++ b/library/src/main/java/ru/terrakok/cicerone/Navigator.java
@@ -4,6 +4,8 @@
 
 package ru.terrakok.cicerone;
 
+import org.jetbrains.annotations.NotNull;
+
 import ru.terrakok.cicerone.commands.Command;
 
 /**
@@ -17,5 +19,5 @@ public interface Navigator {
      *
      * @param commands the navigation command array to apply per single transaction
      */
-    void applyCommands(Command[] commands);
+    void applyCommands(@NotNull Command[] commands);
 }
diff --git a/library/src/main/java/ru/terrakok/cicerone/NavigatorHolder.java b/library/src/main/java/ru/terrakok/cicerone/NavigatorHolder.java
index 79b2c8c..a61e4aa 100644
--- a/library/src/main/java/ru/terrakok/cicerone/NavigatorHolder.java
+++ b/library/src/main/java/ru/terrakok/cicerone/NavigatorHolder.java
@@ -4,6 +4,8 @@
 
 package ru.terrakok.cicerone;
 
+import org.jetbrains.annotations.NotNull;
+
 /**
  * Navigator holder interface.
  * Use it to connect a {@link Navigator} to the {@link Cicerone}.
@@ -15,7 +17,7 @@ public interface NavigatorHolder {
      *
      * @param navigator new active Navigator
      */
-    void setNavigator(Navigator navigator);
+    void setNavigator(@NotNull Navigator navigator);
 
     /**
      * Remove the current Navigator and stop receive commands.
diff --git a/library/src/main/java/ru/terrakok/cicerone/Router.java b/library/src/main/java/ru/terrakok/cicerone/Router.java
index 1e04b99..3243e9c 100644
--- a/library/src/main/java/ru/terrakok/cicerone/Router.java
+++ b/library/src/main/java/ru/terrakok/cicerone/Router.java
@@ -4,6 +4,9 @@
 
 package ru.terrakok.cicerone;
 
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
 import ru.terrakok.cicerone.commands.Back;
 import ru.terrakok.cicerone.commands.BackTo;
 import ru.terrakok.cicerone.commands.Command;
@@ -27,7 +30,7 @@ public Router() {
      *
      * @param screen screen
      */
-    public void navigateTo(Screen screen) {
+    public void navigateTo(@NotNull Screen screen) {
         executeCommands(new Forward(screen));
     }
 
@@ -36,7 +39,7 @@ public void navigateTo(Screen screen) {
      *
      * @param screen screen
      */
-    public void newRootScreen(Screen screen) {
+    public void newRootScreen(@NotNull Screen screen) {
         executeCommands(
                 new BackTo(null),
                 new Replace(screen)
@@ -51,7 +54,7 @@ public void newRootScreen(Screen screen) {
      *
      * @param screen screen
      */
-    public void replaceScreen(Screen screen) {
+    public void replaceScreen(@NotNull Screen screen) {
         executeCommands(new Replace(screen));
     }
 
@@ -62,7 +65,7 @@ public void replaceScreen(Screen screen) {
      *
      * @param screen screen
      */
-    public void backTo(Screen screen) {
+    public void backTo(@Nullable Screen screen) {
         executeCommands(new BackTo(screen));
     }
 
@@ -70,7 +73,7 @@ public void backTo(Screen screen) {
      * Opens several screens inside single transaction.
      * @param screens
      */
-    public void newChain(Screen... screens) {
+    public void newChain(@NotNull Screen... screens) {
         Command[] commands = new Command[screens.length];
         for (int i = 0; i < commands.length; i++) {
             commands[i] = new Forward(screens[i]);
@@ -82,7 +85,7 @@ public void newChain(Screen... screens) {
      * Clear current stack and open several screens inside single transaction.
      * @param screens
      */
-    public void newRootChain(Screen... screens) {
+    public void newRootChain(@NotNull Screen... screens) {
         Command[] commands = new Command[screens.length + 1];
         commands[0] = new BackTo(null);
         if (screens.length > 0) {
diff --git a/library/src/main/java/ru/terrakok/cicerone/Screen.java b/library/src/main/java/ru/terrakok/cicerone/Screen.java
index b229111..0c1652d 100644
--- a/library/src/main/java/ru/terrakok/cicerone/Screen.java
+++ b/library/src/main/java/ru/terrakok/cicerone/Screen.java
@@ -1,11 +1,14 @@
 package ru.terrakok.cicerone;
 
+import org.jetbrains.annotations.NotNull;
+
 /**
  * Screen is class for description application screen.
  */
 public abstract class Screen {
     protected String screenKey = getClass().getCanonicalName();
 
+    @NotNull
     public String getScreenKey() {
         return screenKey;
     }
diff --git a/library/src/main/java/ru/terrakok/cicerone/android/pure/AppNavigator.java b/library/src/main/java/ru/terrakok/cicerone/android/pure/AppNavigator.java
index 1792405..f8256ab 100644
--- a/library/src/main/java/ru/terrakok/cicerone/android/pure/AppNavigator.java
+++ b/library/src/main/java/ru/terrakok/cicerone/android/pure/AppNavigator.java
@@ -6,16 +6,13 @@
 import android.app.FragmentTransaction;
 import android.content.Intent;
 import android.os.Bundle;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import ru.terrakok.cicerone.Navigator;
+import ru.terrakok.cicerone.commands.*;
 
 import java.util.LinkedList;
 
-import ru.terrakok.cicerone.Navigator;
-import ru.terrakok.cicerone.commands.Back;
-import ru.terrakok.cicerone.commands.BackTo;
-import ru.terrakok.cicerone.commands.Command;
-import ru.terrakok.cicerone.commands.Forward;
-import ru.terrakok.cicerone.commands.Replace;
-
 /**
  * Navigator implementation for launch fragments and activities.<br>
  * Feature {@link BackTo} works only for fragments.<br>
@@ -23,30 +20,34 @@
  */
 public class AppNavigator implements Navigator {
 
-    private final Activity activity;
-    private final FragmentManager fragmentManager;
-    private final int containerId;
-    private LinkedList<String> localStackCopy;
+    protected final Activity activity;
+    protected final FragmentManager fragmentManager;
+    protected final int containerId;
+    protected LinkedList<String> localStackCopy;
 
-    public AppNavigator(Activity activity, int containerId) {
+    public AppNavigator(@NotNull Activity activity, int containerId) {
         this(activity, activity.getFragmentManager(), containerId);
     }
 
-    public AppNavigator(Activity activity, FragmentManager fragmentManager, int containerId) {
+    public AppNavigator(@NotNull Activity activity, @NotNull FragmentManager fragmentManager, int containerId) {
         this.activity = activity;
         this.fragmentManager = fragmentManager;
         this.containerId = containerId;
     }
 
     @Override
-    public void applyCommands(Command[] commands) {
+    public void applyCommands(@NotNull Command[] commands) {
         fragmentManager.executePendingTransactions();
 
         //copy stack before apply commands
         copyStackToLocal();
 
         for (Command command : commands) {
-            applyCommand(command);
+            try {
+                applyCommand(command);
+            } catch (RuntimeException e) {
+                errorOnApplyCommand(command, e);
+            }
         }
     }
 
@@ -64,7 +65,7 @@ private void copyStackToLocal() {
      *
      * @param command the navigation command to apply
      */
-    protected void applyCommand(Command command) {
+    protected void applyCommand(@NotNull Command command) {
         if (command instanceof Forward) {
             activityForward((Forward) command);
         } else if (command instanceof Replace) {
@@ -77,7 +78,7 @@ protected void applyCommand(Command command) {
     }
 
 
-    protected void activityForward(Forward command) {
+    protected void activityForward(@NotNull Forward command) {
         AppScreen screen = (AppScreen) command.getScreen();
         Intent activityIntent = screen.getActivityIntent(activity);
 
@@ -90,7 +91,7 @@ protected void activityForward(Forward command) {
         }
     }
 
-    protected void fragmentForward(Forward command) {
+    protected void fragmentForward(@NotNull Forward command) {
         AppScreen screen = (AppScreen) command.getScreen();
         Fragment fragment = createFragment(screen);
 
@@ -123,7 +124,7 @@ protected void activityBack() {
         activity.finish();
     }
 
-    protected void activityReplace(Replace command) {
+    protected void activityReplace(@NotNull Replace command) {
         AppScreen screen = (AppScreen) command.getScreen();
         Intent activityIntent = screen.getActivityIntent(activity);
 
@@ -137,7 +138,7 @@ protected void activityReplace(Replace command) {
         }
     }
 
-    protected void fragmentReplace(Replace command) {
+    protected void fragmentReplace(@NotNull Replace command) {
         AppScreen screen = (AppScreen) command.getScreen();
         Fragment fragment = createFragment(screen);
 
@@ -179,7 +180,7 @@ protected void fragmentReplace(Replace command) {
     /**
      * Performs {@link BackTo} command transition
      */
-    protected void backTo(BackTo command) {
+    protected void backTo(@NotNull BackTo command) {
         if (command.getScreen() == null) {
             backToRoot();
         } else {
@@ -213,10 +214,10 @@ private void backToRoot() {
      * @param nextFragment        next screen fragment
      * @param fragmentTransaction fragment transaction
      */
-    protected void setupFragmentTransaction(Command command,
-                                            Fragment currentFragment,
-                                            Fragment nextFragment,
-                                            FragmentTransaction fragmentTransaction) {
+    protected void setupFragmentTransaction(@NotNull Command command,
+                                            @Nullable Fragment currentFragment,
+                                            @Nullable Fragment nextFragment,
+                                            @NotNull FragmentTransaction fragmentTransaction) {
     }
 
     /**
@@ -226,11 +227,14 @@ protected void setupFragmentTransaction(Command command,
      * @param activityIntent activity intent
      * @return transition options
      */
-    protected Bundle createStartActivityOptions(Command command, Intent activityIntent) {
+    @Nullable
+    protected Bundle createStartActivityOptions(@NotNull Command command, @NotNull Intent activityIntent) {
         return null;
     }
 
-    private void checkAndStartActivity(AppScreen screen, Intent activityIntent, Bundle options) {
+    private void checkAndStartActivity(@NotNull AppScreen screen,
+                                       @NotNull Intent activityIntent,
+                                       @Nullable Bundle options) {
         // Check if we can start activity
         if (activityIntent.resolveActivity(activity.getPackageManager()) != null) {
             activity.startActivity(activityIntent, options);
@@ -245,7 +249,7 @@ private void checkAndStartActivity(AppScreen screen, Intent activityIntent, Bund
      * @param screen         screen
      * @param activityIntent intent passed to start Activity for the {@code screenKey}
      */
-    protected void unexistingActivity(AppScreen screen, Intent activityIntent) {
+    protected void unexistingActivity(@NotNull AppScreen screen, @NotNull Intent activityIntent) {
         // Do nothing by default
     }
 
@@ -255,11 +259,13 @@ protected void unexistingActivity(AppScreen screen, Intent activityIntent) {
      * @param screen screen
      * @return instantiated fragment for the passed screen
      */
-    protected Fragment createFragment(AppScreen screen) {
+    @Nullable
+    protected Fragment createFragment(@NotNull AppScreen screen) {
         Fragment fragment = screen.getFragment();
 
         if (fragment == null) {
             errorWhileCreatingScreen(screen);
+            throw new RuntimeException("Can't create a screen: " + screen.getScreenKey());
         }
         return fragment;
     }
@@ -270,11 +276,29 @@ protected Fragment createFragment(AppScreen screen) {
      *
      * @param screen screen
      */
-    protected void backToUnexisting(AppScreen screen) {
+    protected void backToUnexisting(@NotNull AppScreen screen) {
         backToRoot();
     }
 
-    protected void errorWhileCreatingScreen(AppScreen screen) {
-        throw new RuntimeException("Can't create a screen: " + screen.getScreenKey());
+    /**
+     * Called when we tried to create new intent or fragment but didn't receive them.
+     *
+     * @param screen screen
+     */
+    protected void errorWhileCreatingScreen(@NotNull AppScreen screen) {
+        // Do nothing by default
+    }
+
+    /**
+     * Override this method if you want to handle apply command error.
+     *
+     * @param command command
+     * @param error error
+     */
+    protected void errorOnApplyCommand(
+            @NotNull Command command,
+            @NotNull RuntimeException error
+    ) {
+        throw error;
     }
 }
diff --git a/library/src/main/java/ru/terrakok/cicerone/android/pure/AppScreen.java b/library/src/main/java/ru/terrakok/cicerone/android/pure/AppScreen.java
index d9e9a03..8e409b7 100644
--- a/library/src/main/java/ru/terrakok/cicerone/android/pure/AppScreen.java
+++ b/library/src/main/java/ru/terrakok/cicerone/android/pure/AppScreen.java
@@ -4,6 +4,8 @@
 import android.content.Context;
 import android.content.Intent;
 
+import org.jetbrains.annotations.Nullable;
+
 import ru.terrakok.cicerone.Screen;
 
 /**
@@ -13,10 +15,12 @@
  */
 public abstract class AppScreen extends Screen {
 
+    @Nullable
     public Fragment getFragment() {
         return null;
     }
 
+    @Nullable
     public Intent getActivityIntent(Context context) {
         return null;
     }
diff --git a/library/src/main/java/ru/terrakok/cicerone/android/support/FragmentParams.java b/library/src/main/java/ru/terrakok/cicerone/android/support/FragmentParams.java
new file mode 100644
index 0000000..e3cf57c
--- /dev/null
+++ b/library/src/main/java/ru/terrakok/cicerone/android/support/FragmentParams.java
@@ -0,0 +1,36 @@
+package ru.terrakok.cicerone.android.support;
+
+import android.os.Bundle;
+
+import androidx.fragment.app.Fragment;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public final class FragmentParams {
+
+    @NotNull
+    private final Class<? extends Fragment> fragmentClass;
+    @Nullable
+    private final Bundle arguments;
+
+    @NotNull
+    public final Class<? extends Fragment> getFragmentClass() {
+        return this.fragmentClass;
+    }
+
+    @Nullable
+    public final Bundle getArguments() {
+        return this.arguments;
+    }
+
+    public FragmentParams(@NotNull Class<? extends Fragment> fragmentClass, @Nullable Bundle arguments) {
+        this.fragmentClass = fragmentClass;
+        this.arguments = arguments;
+    }
+
+    public FragmentParams(@NotNull Class<? extends Fragment> fragmentClass) {
+        this.fragmentClass = fragmentClass;
+        this.arguments = null;
+    }
+}
diff --git a/library/src/main/java/ru/terrakok/cicerone/android/support/SupportAppNavigator.java b/library/src/main/java/ru/terrakok/cicerone/android/support/SupportAppNavigator.java
index b5a884a..6f8672d 100644
--- a/library/src/main/java/ru/terrakok/cicerone/android/support/SupportAppNavigator.java
+++ b/library/src/main/java/ru/terrakok/cicerone/android/support/SupportAppNavigator.java
@@ -7,16 +7,13 @@
 import androidx.fragment.app.FragmentActivity;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentTransaction;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import ru.terrakok.cicerone.Navigator;
+import ru.terrakok.cicerone.commands.*;
 
 import java.util.LinkedList;
 
-import ru.terrakok.cicerone.Navigator;
-import ru.terrakok.cicerone.commands.Back;
-import ru.terrakok.cicerone.commands.BackTo;
-import ru.terrakok.cicerone.commands.Command;
-import ru.terrakok.cicerone.commands.Forward;
-import ru.terrakok.cicerone.commands.Replace;
-
 /**
  * Navigator implementation for launch fragments and activities.<br>
  * Feature {@link BackTo} works only for fragments.<br>
@@ -24,30 +21,34 @@
  */
 public class SupportAppNavigator implements Navigator {
 
-    private final Activity activity;
-    private final FragmentManager fragmentManager;
-    private final int containerId;
-    private LinkedList<String> localStackCopy;
+    protected final Activity activity;
+    protected final FragmentManager fragmentManager;
+    protected final int containerId;
+    protected LinkedList<String> localStackCopy;
 
-    public SupportAppNavigator(FragmentActivity activity, int containerId) {
+    public SupportAppNavigator(@NotNull FragmentActivity activity, int containerId) {
         this(activity, activity.getSupportFragmentManager(), containerId);
     }
 
-    public SupportAppNavigator(FragmentActivity activity, FragmentManager fragmentManager, int containerId) {
+    public SupportAppNavigator(@NotNull FragmentActivity activity, @NotNull FragmentManager fragmentManager, int containerId) {
         this.activity = activity;
         this.fragmentManager = fragmentManager;
         this.containerId = containerId;
     }
 
     @Override
-    public void applyCommands(Command[] commands) {
+    public void applyCommands(@NotNull Command[] commands) {
         fragmentManager.executePendingTransactions();
 
         //copy stack before apply commands
         copyStackToLocal();
 
         for (Command command : commands) {
-            applyCommand(command);
+            try {
+                applyCommand(command);
+            } catch (RuntimeException e) {
+                errorOnApplyCommand(command, e);
+            }
         }
     }
 
@@ -65,7 +66,7 @@ private void copyStackToLocal() {
      *
      * @param command the navigation command to apply
      */
-    protected void applyCommand(Command command) {
+    protected void applyCommand(@NotNull Command command) {
         if (command instanceof Forward) {
             activityForward((Forward) command);
         } else if (command instanceof Replace) {
@@ -78,7 +79,7 @@ protected void applyCommand(Command command) {
     }
 
 
-    protected void activityForward(Forward command) {
+    protected void activityForward(@NotNull Forward command) {
         SupportAppScreen screen = (SupportAppScreen) command.getScreen();
         Intent activityIntent = screen.getActivityIntent(activity);
 
@@ -91,9 +92,11 @@ protected void activityForward(Forward command) {
         }
     }
 
-    protected void fragmentForward(Forward command) {
+    protected void fragmentForward(@NotNull Forward command) {
         SupportAppScreen screen = (SupportAppScreen) command.getScreen();
-        Fragment fragment = createFragment(screen);
+
+        FragmentParams fragmentParams = screen.getFragmentParams();
+        Fragment fragment = fragmentParams == null ? createFragment(screen) : null;
 
         FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
 
@@ -101,11 +104,15 @@ protected void fragmentForward(Forward command) {
                 command,
                 fragmentManager.findFragmentById(containerId),
                 fragment,
-                fragmentTransaction
-        );
+                fragmentTransaction);
+
+        if (fragmentParams != null) {
+            fragmentTransaction.replace(containerId, fragmentParams.getFragmentClass(), fragmentParams.getArguments());
+        } else {
+            fragmentTransaction.replace(containerId, fragment);
+        }
 
         fragmentTransaction
-                .replace(containerId, fragment)
                 .addToBackStack(screen.getScreenKey())
                 .commit();
         localStackCopy.add(screen.getScreenKey());
@@ -124,7 +131,7 @@ protected void activityBack() {
         activity.finish();
     }
 
-    protected void activityReplace(Replace command) {
+    protected void activityReplace(@NotNull Replace command) {
         SupportAppScreen screen = (SupportAppScreen) command.getScreen();
         Intent activityIntent = screen.getActivityIntent(activity);
 
@@ -138,9 +145,11 @@ protected void activityReplace(Replace command) {
         }
     }
 
-    protected void fragmentReplace(Replace command) {
+    protected void fragmentReplace(@NotNull Replace command) {
         SupportAppScreen screen = (SupportAppScreen) command.getScreen();
-        Fragment fragment = createFragment(screen);
+
+        FragmentParams fragmentParams = screen.getFragmentParams();
+        Fragment fragment = fragmentParams == null ? createFragment(screen) : null;
 
         if (localStackCopy.size() > 0) {
             fragmentManager.popBackStack();
@@ -155,8 +164,15 @@ protected void fragmentReplace(Replace command) {
                     fragmentTransaction
             );
 
+            if (fragmentParams != null) {
+                fragmentTransaction.replace(
+                        containerId,
+                        fragmentParams.getFragmentClass(),
+                        fragmentParams.getArguments());
+            } else {
+                fragmentTransaction.replace(containerId, fragment);
+            }
             fragmentTransaction
-                    .replace(containerId, fragment)
                     .addToBackStack(screen.getScreenKey())
                     .commit();
             localStackCopy.add(screen.getScreenKey());
@@ -180,7 +196,7 @@ protected void fragmentReplace(Replace command) {
     /**
      * Performs {@link BackTo} command transition
      */
-    protected void backTo(BackTo command) {
+    protected void backTo(@NotNull BackTo command) {
         if (command.getScreen() == null) {
             backToRoot();
         } else {
@@ -214,10 +230,10 @@ private void backToRoot() {
      * @param nextFragment        next screen fragment
      * @param fragmentTransaction fragment transaction
      */
-    protected void setupFragmentTransaction(Command command,
-                                            Fragment currentFragment,
-                                            Fragment nextFragment,
-                                            FragmentTransaction fragmentTransaction) {
+    protected void setupFragmentTransaction(@NotNull Command command,
+                                            @Nullable Fragment currentFragment,
+                                            @Nullable Fragment nextFragment,
+                                            @NotNull FragmentTransaction fragmentTransaction) {
     }
 
     /**
@@ -227,11 +243,12 @@ protected void setupFragmentTransaction(Command command,
      * @param activityIntent activity intent
      * @return transition options
      */
-    protected Bundle createStartActivityOptions(Command command, Intent activityIntent) {
+    @Nullable
+    protected Bundle createStartActivityOptions(@NotNull Command command, @NotNull Intent activityIntent) {
         return null;
     }
 
-    private void checkAndStartActivity(SupportAppScreen screen, Intent activityIntent, Bundle options) {
+    private void checkAndStartActivity(@NotNull SupportAppScreen screen, @NotNull Intent activityIntent, @Nullable Bundle options) {
         // Check if we can start activity
         if (activityIntent.resolveActivity(activity.getPackageManager()) != null) {
             activity.startActivity(activityIntent, options);
@@ -246,7 +263,7 @@ private void checkAndStartActivity(SupportAppScreen screen, Intent activityInten
      * @param screen         screen
      * @param activityIntent intent passed to start Activity for the {@code screenKey}
      */
-    protected void unexistingActivity(SupportAppScreen screen, Intent activityIntent) {
+    protected void unexistingActivity(@NotNull SupportAppScreen screen, @NotNull Intent activityIntent) {
         // Do nothing by default
     }
 
@@ -256,11 +273,13 @@ protected void unexistingActivity(SupportAppScreen screen, Intent activityIntent
      * @param screen screen
      * @return instantiated fragment for the passed screen
      */
-    protected Fragment createFragment(SupportAppScreen screen) {
+    @Nullable
+    protected Fragment createFragment(@NotNull SupportAppScreen screen) {
         Fragment fragment = screen.getFragment();
 
         if (fragment == null) {
             errorWhileCreatingScreen(screen);
+            throw new RuntimeException("Can't create a screen: " + screen.getScreenKey());
         }
         return fragment;
     }
@@ -271,11 +290,29 @@ protected Fragment createFragment(SupportAppScreen screen) {
      *
      * @param screen screen
      */
-    protected void backToUnexisting(SupportAppScreen screen) {
+    protected void backToUnexisting(@NotNull SupportAppScreen screen) {
         backToRoot();
     }
 
-    protected void errorWhileCreatingScreen(SupportAppScreen screen) {
-        throw new RuntimeException("Can't create a screen: " + screen.getScreenKey());
+    /**
+     * Called when we tried to create new intent or fragment but didn't receive them.
+     *
+     * @param screen screen
+     */
+    protected void errorWhileCreatingScreen(@NotNull SupportAppScreen screen) {
+        // Do nothing by default
+    }
+
+    /**
+     * Override this method if you want to handle apply command error.
+     *
+     * @param command command
+     * @param error error
+     */
+    protected void errorOnApplyCommand(
+            @NotNull Command command,
+            @NotNull RuntimeException error
+    ) {
+        throw error;
     }
 }
diff --git a/library/src/main/java/ru/terrakok/cicerone/android/support/SupportAppScreen.java b/library/src/main/java/ru/terrakok/cicerone/android/support/SupportAppScreen.java
index 554d17f..067ec40 100644
--- a/library/src/main/java/ru/terrakok/cicerone/android/support/SupportAppScreen.java
+++ b/library/src/main/java/ru/terrakok/cicerone/android/support/SupportAppScreen.java
@@ -2,8 +2,11 @@
 
 import android.content.Context;
 import android.content.Intent;
-import androidx.fragment.app.Fragment;
 
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import androidx.fragment.app.Fragment;
 import ru.terrakok.cicerone.Screen;
 
 /**
@@ -13,11 +16,18 @@
  */
 public abstract class SupportAppScreen extends Screen {
 
+    @Nullable
     public Fragment getFragment() {
         return null;
     }
 
-    public Intent getActivityIntent(Context context) {
+    @Nullable
+    public Intent getActivityIntent(@NotNull Context context) {
+        return null;
+    }
+
+    @Nullable
+    public FragmentParams getFragmentParams() {
         return null;
     }
 }
diff --git a/library/src/main/java/ru/terrakok/cicerone/commands/BackTo.java b/library/src/main/java/ru/terrakok/cicerone/commands/BackTo.java
index 7df8570..2cf11a0 100644
--- a/library/src/main/java/ru/terrakok/cicerone/commands/BackTo.java
+++ b/library/src/main/java/ru/terrakok/cicerone/commands/BackTo.java
@@ -4,6 +4,8 @@
 
 package ru.terrakok.cicerone.commands;
 
+import org.jetbrains.annotations.Nullable;
+
 import ru.terrakok.cicerone.Navigator;
 import ru.terrakok.cicerone.Screen;
 
@@ -20,10 +22,11 @@ public class BackTo implements Command {
      *
      * @param screen screen
      */
-    public BackTo(Screen screen) {
+    public BackTo(@Nullable Screen screen) {
         this.screen = screen;
     }
 
+    @Nullable
     public Screen getScreen() {
         return screen;
     }
diff --git a/library/src/main/java/ru/terrakok/cicerone/commands/Forward.java b/library/src/main/java/ru/terrakok/cicerone/commands/Forward.java
index 2dc5221..46a91e2 100644
--- a/library/src/main/java/ru/terrakok/cicerone/commands/Forward.java
+++ b/library/src/main/java/ru/terrakok/cicerone/commands/Forward.java
@@ -4,6 +4,8 @@
 
 package ru.terrakok.cicerone.commands;
 
+import org.jetbrains.annotations.NotNull;
+
 import ru.terrakok.cicerone.Screen;
 
 /**
@@ -17,10 +19,11 @@ public class Forward implements Command {
      *
      * @param screen screen
      */
-    public Forward(Screen screen) {
+    public Forward(@NotNull Screen screen) {
         this.screen = screen;
     }
 
+    @NotNull
     public Screen getScreen() {
         return screen;
     }
diff --git a/library/src/main/java/ru/terrakok/cicerone/commands/Replace.java b/library/src/main/java/ru/terrakok/cicerone/commands/Replace.java
index a7d2e19..d34489a 100644
--- a/library/src/main/java/ru/terrakok/cicerone/commands/Replace.java
+++ b/library/src/main/java/ru/terrakok/cicerone/commands/Replace.java
@@ -4,12 +4,15 @@
 
 package ru.terrakok.cicerone.commands;
 
+import org.jetbrains.annotations.NotNull;
+
 import ru.terrakok.cicerone.Screen;
 
 /**
  * Replaces the current screen.
  */
 public class Replace implements Command {
+    @NotNull
     private Screen screen;
 
     /**
@@ -17,10 +20,11 @@ public class Replace implements Command {
      *
      * @param screen screen
      */
-    public Replace(Screen screen) {
+    public Replace(@NotNull Screen screen) {
         this.screen = screen;
     }
 
+    @NotNull
     public Screen getScreen() {
         return screen;
     }
diff --git a/library/stub-android/src/main/java/androidx/fragment/app/FragmentTransaction.java b/library/stub-android/src/main/java/androidx/fragment/app/FragmentTransaction.java
index ce708dc..a4a8731 100644
--- a/library/stub-android/src/main/java/androidx/fragment/app/FragmentTransaction.java
+++ b/library/stub-android/src/main/java/androidx/fragment/app/FragmentTransaction.java
@@ -1,5 +1,7 @@
 package androidx.fragment.app;
 
+import android.os.Bundle;
+
 /**
  * Created by Konstantin Tckhovrebov (aka @terrakok)
  * on 11.10.16
@@ -10,6 +12,13 @@ public FragmentTransaction replace(int containerViewId, Fragment fragment) {
         throw new RuntimeException("Stub!");
     }
 
+    public final FragmentTransaction replace(
+            int containerViewId,
+            Class<? extends Fragment> fragmentClass,
+            Bundle args) {
+        throw new RuntimeException("Stub!");
+    }
+
     public FragmentTransaction addToBackStack(String name) {
         throw new RuntimeException("Stub!");
     }