diff --git a/src/main/java/ru/nanit/limbo/connection/pipeline/PacketEncoder.java b/src/main/java/ru/nanit/limbo/connection/pipeline/PacketEncoder.java
index 26e9282..4885aa8 100644
--- a/src/main/java/ru/nanit/limbo/connection/pipeline/PacketEncoder.java
+++ b/src/main/java/ru/nanit/limbo/connection/pipeline/PacketEncoder.java
@@ -60,7 +60,7 @@ public class PacketEncoder extends MessageToByteEncoder<Packet> {
         try {
             packet.encode(msg, version);
 
-            if (Logger.getLevel() >= 3) {
+            if (Logger.getLevel() >= Logger.Level.DEBUG.getIndex()) {
                 Logger.debug("Sending %s[0x%s] packet (%d bytes)", packet.toString(), Integer.toHexString(packetId), msg.readableBytes());
             }
         } catch (Exception e) {
diff --git a/src/main/java/ru/nanit/limbo/server/Command.java b/src/main/java/ru/nanit/limbo/server/Command.java
new file mode 100644
index 0000000..c1c7419
--- /dev/null
+++ b/src/main/java/ru/nanit/limbo/server/Command.java
@@ -0,0 +1,9 @@
+package ru.nanit.limbo.server;
+
+public interface Command {
+
+    void execute();
+
+    String description();
+
+}
diff --git a/src/main/java/ru/nanit/limbo/server/CommandManager.java b/src/main/java/ru/nanit/limbo/server/CommandManager.java
index fbb9192..e05fc18 100644
--- a/src/main/java/ru/nanit/limbo/server/CommandManager.java
+++ b/src/main/java/ru/nanit/limbo/server/CommandManager.java
@@ -1,29 +1,59 @@
 package ru.nanit.limbo.server;
 
-import java.util.NoSuchElementException;
-import java.util.Scanner;
+import ru.nanit.limbo.server.commands.CmdConn;
+import ru.nanit.limbo.server.commands.CmdHelp;
+import ru.nanit.limbo.server.commands.CmdMem;
+import ru.nanit.limbo.server.commands.CmdStop;
+
+import java.util.*;
 
 public final class CommandManager extends Thread {
 
+    private final Map<String, Command> commands = new HashMap<>();
+
+    public Map<String, Command> getCommands() {
+        return Collections.unmodifiableMap(commands);
+    }
+
+    public Command getCommand(String name) {
+        return commands.get(name.toLowerCase());
+    }
+
+    public void register(String name, Command cmd) {
+        commands.put(name.toLowerCase(), cmd);
+    }
+
     @Override
     public void run() {
         Scanner scanner = new Scanner(System.in);
-        String line;
+        String command;
 
         while (true) {
             try {
-                line = scanner.nextLine();
+                command = scanner.nextLine().trim();
             } catch (NoSuchElementException e) {
                 break;
             }
 
-            if (line.equalsIgnoreCase("stop")) {
-                System.exit(0);
+            Command handler = getCommand(command);
+
+            if (handler != null) {
+                try {
+                    handler.execute();
+                } catch (Throwable t) {
+                    Logger.error("Cannot execute command:", t);
+                }
                 continue;
             }
 
-            Logger.info("Unknown command");
+            Logger.info("Unknown command. Type \"help\" to get commands list");
         }
     }
 
+    public void registerAll(LimboServer server) {
+        register("help", new CmdHelp(server));
+        register("conn", new CmdConn(server));
+        register("mem", new CmdMem());
+        register("stop", new CmdStop());
+    }
 }
diff --git a/src/main/java/ru/nanit/limbo/server/LimboServer.java b/src/main/java/ru/nanit/limbo/server/LimboServer.java
index 74b3c5b..a9ada1c 100644
--- a/src/main/java/ru/nanit/limbo/server/LimboServer.java
+++ b/src/main/java/ru/nanit/limbo/server/LimboServer.java
@@ -49,6 +49,8 @@ public final class LimboServer {
     private EventLoopGroup bossGroup;
     private EventLoopGroup workerGroup;
 
+    private CommandManager commandManager;
+
     public LimboConfig getConfig() {
         return config;
     }
@@ -65,6 +67,10 @@ public final class LimboServer {
         return dimensionRegistry;
     }
 
+    public CommandManager getCommandManager() {
+        return commandManager;
+    }
+
     public void start() throws Exception {
         Logger.info("Starting server...");
 
@@ -90,7 +96,11 @@ public final class LimboServer {
 
         Logger.setLevel(config.getDebugLevel());
 
-        new CommandManager().start();
+        commandManager = new CommandManager();
+        commandManager.registerAll(this);
+        commandManager.start();
+
+        System.gc();
     }
 
     private void startBootstrap() {
diff --git a/src/main/java/ru/nanit/limbo/server/commands/CmdConn.java b/src/main/java/ru/nanit/limbo/server/commands/CmdConn.java
new file mode 100644
index 0000000..b93e6f5
--- /dev/null
+++ b/src/main/java/ru/nanit/limbo/server/commands/CmdConn.java
@@ -0,0 +1,24 @@
+package ru.nanit.limbo.server.commands;
+
+import ru.nanit.limbo.server.Command;
+import ru.nanit.limbo.server.LimboServer;
+import ru.nanit.limbo.server.Logger;
+
+public class CmdConn implements Command {
+
+    private final LimboServer server;
+
+    public CmdConn(LimboServer server) {
+        this.server = server;
+    }
+
+    @Override
+    public void execute() {
+        Logger.info("Connections: %d", server.getConnections().getCount());
+    }
+
+    @Override
+    public String description() {
+        return "Display connections count";
+    }
+}
diff --git a/src/main/java/ru/nanit/limbo/server/commands/CmdHelp.java b/src/main/java/ru/nanit/limbo/server/commands/CmdHelp.java
new file mode 100644
index 0000000..7adeb6f
--- /dev/null
+++ b/src/main/java/ru/nanit/limbo/server/commands/CmdHelp.java
@@ -0,0 +1,37 @@
+package ru.nanit.limbo.server.commands;
+
+import ru.nanit.limbo.server.Command;
+import ru.nanit.limbo.server.LimboServer;
+
+import java.util.Map;
+
+public class CmdHelp implements Command {
+
+    private final LimboServer server;
+
+    public CmdHelp(LimboServer server) {
+        this.server = server;
+    }
+
+    @Override
+    public void execute() {
+        StringBuilder msg = new StringBuilder();
+        Map<String, Command> commands = server.getCommandManager().getCommands();
+
+        for (Map.Entry<String, Command> entry : commands.entrySet()) {
+            msg.append("\n");
+            msg.append(entry.getKey());
+            msg.append(" - ");
+            msg.append(entry.getValue().description());
+        }
+
+        msg.append("\n");
+
+        System.out.println(msg);
+    }
+
+    @Override
+    public String description() {
+        return "Show this message";
+    }
+}
diff --git a/src/main/java/ru/nanit/limbo/server/commands/CmdMem.java b/src/main/java/ru/nanit/limbo/server/commands/CmdMem.java
new file mode 100644
index 0000000..7809f81
--- /dev/null
+++ b/src/main/java/ru/nanit/limbo/server/commands/CmdMem.java
@@ -0,0 +1,27 @@
+package ru.nanit.limbo.server.commands;
+
+import ru.nanit.limbo.server.Command;
+import ru.nanit.limbo.server.Logger;
+
+public class CmdMem implements Command {
+
+    @Override
+    public void execute() {
+        Runtime runtime = Runtime.getRuntime();
+        long mb = 1024 * 1024;
+        long used = (runtime.totalMemory() - runtime.freeMemory()) / mb;
+        long total = runtime.totalMemory() / mb;
+        long free = runtime.freeMemory() / mb;
+        long max = runtime.maxMemory() / mb;
+
+        Logger.info("Used: %d MB", used);
+        Logger.info("Total: %d MB", total);
+        Logger.info("Free: %d MB", free);
+        Logger.info("Max: %d MB", max);
+    }
+
+    @Override
+    public String description() {
+        return "Display memory usage";
+    }
+}
diff --git a/src/main/java/ru/nanit/limbo/server/commands/CmdStop.java b/src/main/java/ru/nanit/limbo/server/commands/CmdStop.java
new file mode 100644
index 0000000..4120211
--- /dev/null
+++ b/src/main/java/ru/nanit/limbo/server/commands/CmdStop.java
@@ -0,0 +1,16 @@
+package ru.nanit.limbo.server.commands;
+
+import ru.nanit.limbo.server.Command;
+
+public class CmdStop implements Command {
+
+    @Override
+    public void execute() {
+        System.exit(0);
+    }
+
+    @Override
+    public String description() {
+        return "Stop the server";
+    }
+}