diff --git a/src/main/java/org/ultramine/commands/CommandContext.java b/src/main/java/org/ultramine/commands/CommandContext.java
index 86466eb..4dab2e5 100644
--- a/src/main/java/org/ultramine/commands/CommandContext.java
+++ b/src/main/java/org/ultramine/commands/CommandContext.java
@@ -11,17 +11,24 @@
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 import net.minecraft.server.MinecraftServer;
+import net.minecraft.util.ChatComponentTranslation;
 import net.minecraft.util.EnumChatFormatting;
 import net.minecraft.util.IChatComponent;
 import net.minecraft.world.WorldServer;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.ultramine.core.economy.service.Economy;
+import org.ultramine.core.economy.account.PlayerAccount;
 import org.ultramine.core.service.InjectService;
 import org.ultramine.server.data.ServerDataLoader;
 import org.ultramine.server.data.player.PlayerData;
 import org.ultramine.server.util.BasicTypeFormatter;
 import org.ultramine.server.util.BasicTypeParser;
 import org.ultramine.core.permissions.Permissions;
+import org.ultramine.server.util.GlobalExecutors;
 
+import javax.annotation.Nullable;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -29,11 +36,16 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
 
 public class CommandContext
 {
 	@InjectService
 	private static Permissions perms;
+	@InjectService
+	private static Economy economy;
+	private static final Logger log = LogManager.getLogger();
 	private ICommandSender sender;
 	private String[] args;
 	private IExtendedCommand command;
@@ -148,11 +160,20 @@
 		if(contains(arg))
 			checkSenderPermission(permission, msg);
 	}
-	
-	
+
+
+	/* thread-safe */
+	public void sendMessage(IChatComponent comp)
+	{
+		if(Thread.currentThread() == getServer().getServerThread())
+			sender.addChatMessage(comp);
+		else
+			GlobalExecutors.nextTick().execute(() -> sender.addChatMessage(comp));
+	}
+
 	public void sendMessage(EnumChatFormatting tplColor, EnumChatFormatting argsColor, String msg, Object... args)
 	{
-		sender.addChatMessage(BasicTypeFormatter.formatMessage(tplColor, argsColor, msg, args));
+		sendMessage(BasicTypeFormatter.formatMessage(tplColor, argsColor, msg, args));
 	}
 	
 	public void sendMessage(EnumChatFormatting argsColor, String msg, Object... args)
@@ -241,6 +262,63 @@
 		return getServer().getConfigurationManager().getDataLoader();
 	}
 
+	/* thread-safe */
+	public void handleException(@Nullable Throwable throwable)
+	{
+		if(throwable == null)
+			return;
+		if(throwable instanceof CompletionException && throwable.getCause() != null)
+			throwable = throwable.getCause();
+		if(throwable instanceof WrongUsageException)
+		{
+			CommandException cmdEx = (CommandException) throwable;
+			ChatComponentTranslation msg = new ChatComponentTranslation("commands.generic.usage", new ChatComponentTranslation(cmdEx.getMessage(), cmdEx.getErrorOjbects()));
+			msg.getChatStyle().setColor(EnumChatFormatting.RED);
+			sendMessage(msg);
+		}
+		else if(throwable instanceof CommandException)
+		{
+			CommandException cmdEx = (CommandException) throwable;
+			ChatComponentTranslation msg = new ChatComponentTranslation(cmdEx.getMessage(), cmdEx.getErrorOjbects());
+			msg.getChatStyle().setColor(EnumChatFormatting.RED);
+			sendMessage(msg);
+		}
+		else
+		{
+			ChatComponentTranslation msg = new ChatComponentTranslation("commands.generic.exception");
+			msg.getChatStyle().setColor(EnumChatFormatting.RED);
+			sendMessage(msg);
+			log.error("Couldn\'t process command", throwable);
+		}
+	}
+
+	/* thread-safe */
+	public CompletableFuture<Void> handleException(CompletableFuture<?> future)
+	{
+		return future.handle((o, throwable) -> {
+			handleException(throwable);
+			return null;
+		});
+	}
+
+	/* thread-safe */
+	public void finishAfter(CompletableFuture<?> future)
+	{
+		future.whenComplete((o, throwable) -> finish(throwable));
+	}
+
+	/* thread-safe */
+	public void finish()
+	{
+		// TODO For async commands, respond RCon only after this method invocation
+	}
+
+	public void finish(@Nullable Throwable throwable)
+	{
+		handleException(throwable);
+		finish();
+	}
+
 
 	public class Argument
 	{
@@ -391,6 +469,11 @@
 		{
 			return new OfflinePlayer(getServer(), asPlayerData());
 		}
+
+		public PlayerAccount asAccount()
+		{
+			return economy.getPlayerAccount(asPlayerData().getProfile());
+		}
 		
 		public WorldServer asWorld()
 		{
diff --git a/src/main/java/org/ultramine/commands/basic/TechCommands.java b/src/main/java/org/ultramine/commands/basic/TechCommands.java
index 417875e..a573f26 100644
--- a/src/main/java/org/ultramine/commands/basic/TechCommands.java
+++ b/src/main/java/org/ultramine/commands/basic/TechCommands.java
@@ -36,13 +36,10 @@
 import org.ultramine.server.UltramineServerModContainer;
 import org.ultramine.server.BackupManager.BackupDescriptor;
 import org.ultramine.server.WorldsConfig.WorldConfig;
-import org.ultramine.server.WorldsConfig.WorldConfig.Border;
 import org.ultramine.server.WorldsConfig.WorldConfig.ImportFrom;
 import org.ultramine.server.chunk.ChunkProfiler;
-import org.ultramine.server.chunk.IChunkLoadCallback;
 import org.ultramine.server.chunk.OffHeapChunkStorage;
 import org.ultramine.server.util.BasicTypeParser;
-import org.ultramine.server.util.GlobalExecutors;
 import org.ultramine.server.world.MultiWorld;
 import org.ultramine.server.world.WorldDescriptor;
 import org.ultramine.server.world.WorldState;
@@ -290,7 +287,8 @@
 				ctx.sendMessage(success);
 			else
 				ctx.sendMessage(RED, RED, fail, e.toString());
-		}, GlobalExecutors.nextTick());
+			ctx.finish();
+		});
 	}
 
 	@Command(
diff --git a/src/main/java/org/ultramine/server/util/GlobalExecutors.java b/src/main/java/org/ultramine/server/util/GlobalExecutors.java
index dc08c9e..bbcc5b0 100644
--- a/src/main/java/org/ultramine/server/util/GlobalExecutors.java
+++ b/src/main/java/org/ultramine/server/util/GlobalExecutors.java
@@ -1,5 +1,6 @@
 package org.ultramine.server.util;
 
+import java.util.concurrent.Executor;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.SynchronousQueue;
@@ -7,6 +8,7 @@
 import java.util.concurrent.TimeUnit;
 
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import net.minecraft.server.MinecraftServer;
 import org.ultramine.server.internal.SyncServerExecutorImpl;
 
 public class GlobalExecutors
@@ -17,7 +19,18 @@
 			60L, TimeUnit.SECONDS,
 			new SynchronousQueue<Runnable>(),
 			new ThreadFactoryBuilder().setNameFormat("UM IO cached  #%d").setDaemon(true).build());
-	private static final SyncServerExecutor sync = new SyncServerExecutorImpl();
+	private static final SyncServerExecutor syncNextTick = new SyncServerExecutorImpl();
+	private static final Executor syncNow = new Executor()
+	{
+		@Override
+		public void execute(Runnable toRun)
+		{
+			if(Thread.currentThread() == MinecraftServer.getServer().getServerThread())
+				toRun.run();
+			else
+				syncNextTick.execute(toRun);
+		}
+	};
 
 	/**
 	 * Обрабатывает задачи на сохранение чего-либо на диск/в БД. Используется
@@ -56,6 +69,15 @@
 	 */
 	public static SyncServerExecutor nextTick()
 	{
-		return sync;
+		return syncNextTick;
+	}
+
+	/**
+	 * Executes tasks in main server thread. Executes synchronously, in {@code execute} method context, if it is invoked
+	 * from main server thread, or on next tick otherwise.
+	 */
+	public static Executor syncServer()
+	{
+		return syncNow;
 	}
 }