diff --git a/.gitignore b/.gitignore
index 8840fe9..9cd8624 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,4 @@
 *.o
-
 server/players.json
 client/game
+server/server
diff --git a/assets/heightmap.bin b/assets/heightmap.bin
index 9647afc..9416b45 100644
Binary files a/assets/heightmap.bin and b/assets/heightmap.bin differ
diff --git a/assets/heightmap.png b/assets/heightmap.png
index 38acdbb..41d7688 100644
Binary files a/assets/heightmap.png and b/assets/heightmap.png differ
diff --git a/client/main.cpp b/client/main.cpp
index b56cc57..f7f6540 100644
--- a/client/main.cpp
+++ b/client/main.cpp
@@ -123,6 +123,10 @@ class Game {
 	bool editMode = false;
 	std::string loginError = "";
 	std::string currentUsername = "";
+	
+	// Heartbeat timing
+	float lastHeartbeatTime = 0.0f;
+	const float HEARTBEAT_INTERVAL = 5.0f; // Send heartbeat every 5 seconds
 
 public:
 	Game() {
@@ -261,6 +265,14 @@ private:
 		// Send normalized movement direction to server (server handles speed)
 		if (moveInput.x != 0 || moveInput.z != 0) {
 			network.sendMove(moveInput.x, 0, moveInput.z);
+			lastHeartbeatTime = GetTime(); // Reset heartbeat timer when moving
+		}
+		
+		// Send periodic heartbeats when not moving
+		float currentTime = GetTime();
+		if (currentTime - lastHeartbeatTime >= HEARTBEAT_INTERVAL) {
+			network.sendHeartbeat();
+			lastHeartbeatTime = currentTime;
 		}
 
 		// Handle color change with arrow keys
diff --git a/client/net/NetworkManager.cpp b/client/net/NetworkManager.cpp
index 37733f1..7175ef1 100644
--- a/client/net/NetworkManager.cpp
+++ b/client/net/NetworkManager.cpp
@@ -250,6 +250,16 @@ void NetworkManager::sendColorChange(const std::string& newColor) {
     socket.send_to(buffer(msg), serverEndpoint);
 }
 
+void NetworkManager::sendHeartbeat() {
+    if (!connected) return;
+    
+    std::array<uint8_t, 5> msg{};
+    msg[0] = static_cast<uint8_t>(MessageType::Heartbeat);
+    uint32_t id = playerID;
+    std::memcpy(&msg[1], &id, sizeof(id));
+    socket.send_to(buffer(msg), serverEndpoint);
+}
+
 Vector3 NetworkManager::getPosition() {
     std::lock_guard lock(positionMutex);
     return serverPosition;
diff --git a/client/net/NetworkManager.hpp b/client/net/NetworkManager.hpp
index db2fd8a..d91a60b 100644
--- a/client/net/NetworkManager.hpp
+++ b/client/net/NetworkManager.hpp
@@ -24,7 +24,8 @@ enum class MessageType : uint8_t {
     ChangeColor = 0x09,
     ColorChanged = 0x0A,
     LoginResponse = 0x0B,
-    Logout = 0x0C
+    Logout = 0x0C,
+    Heartbeat = 0x0D
 };
 
 struct RemotePlayer {
@@ -44,6 +45,7 @@ public:
     void sendLogout();
     void sendMove(float dx, float dy, float dz);
     void sendColorChange(const std::string& newColor);
+    void sendHeartbeat();
 
     Vector3 getPosition();
     bool isConnected() const { return connected; }
diff --git a/server/net/packets.go b/server/net/packets.go
index 895a7d8..feb2811 100644
--- a/server/net/packets.go
+++ b/server/net/packets.go
@@ -19,6 +19,7 @@ const (
 	MSG_COLOR_CHANGED  = 0x0A
 	MSG_LOGIN_RESPONSE = 0x0B
 	MSG_LOGOUT         = 0x0C
+	MSG_HEARTBEAT      = 0x0D
 )
 
 // Vec3 represents a 3D vector
@@ -181,6 +182,16 @@ func DecodeLogoutPacket(data []byte) (playerID uint32, ok bool) {
 		return 0, false
 	}
 	
+	playerID = binary.LittleEndian.Uint32(data[1:5])
+	return playerID, true
+}
+
+// DecodeHeartbeatPacket decodes a heartbeat packet
+func DecodeHeartbeatPacket(data []byte) (playerID uint32, ok bool) {
+	if len(data) < 5 {
+		return 0, false
+	}
+	
 	playerID = binary.LittleEndian.Uint32(data[1:5])
 	return playerID, true
 }
\ No newline at end of file
diff --git a/server/net/server.go b/server/net/server.go
index 730d8b0..69f3320 100644
--- a/server/net/server.go
+++ b/server/net/server.go
@@ -83,7 +83,7 @@ func (s *Server) Run() error {
 
 	// Start player timeout checker
 	go func() {
-		ticker := time.NewTicker(5 * time.Second)
+		ticker := time.NewTicker(10 * time.Second)
 		defer ticker.Stop()
 		for range ticker.C {
 			s.checkTimeouts()
@@ -115,6 +115,8 @@ func (s *Server) Run() error {
 			s.handleColorChange(buffer[:n], addr)
 		case MSG_LOGOUT:
 			s.handleLogout(buffer[:n], addr)
+		case MSG_HEARTBEAT:
+			s.handleHeartbeat(buffer[:n], addr)
 		}
 	}
 }
@@ -210,7 +212,7 @@ func (s *Server) handleLogin(data []byte, addr *net.UDPAddr) {
 	s.saveUserData()
 }
 
-func (s *Server) handleMove(data []byte, _ *net.UDPAddr) {
+func (s *Server) handleMove(data []byte, addr *net.UDPAddr) {
 	playerID, delta, ok := DecodeMovePacket(data)
 	if !ok {
 		return
@@ -223,6 +225,9 @@ func (s *Server) handleMove(data []byte, _ *net.UDPAddr) {
 		return
 	}
 
+	// Update the player's address in case it changed (NAT, port change, etc.)
+	player.Address = addr
+	
 	// Server-authoritative movement
 	deltaTime := float32(0.016) // 60fps
 	newX := player.Position.X + delta.X*15.0*deltaTime
@@ -289,7 +294,7 @@ func (s *Server) handleLogout(data []byte, _ *net.UDPAddr) {
 	s.saveUserData()
 }
 
-func (s *Server) handleColorChange(data []byte, _ *net.UDPAddr) {
+func (s *Server) handleColorChange(data []byte, addr *net.UDPAddr) {
 	playerID, newColor, ok := DecodeColorChangePacket(data)
 	if !ok {
 		return
@@ -310,6 +315,9 @@ func (s *Server) handleColorChange(data []byte, _ *net.UDPAddr) {
 		return
 	}
 
+	// Update the player's address and last seen time
+	player.Address = addr
+	player.LastSeen = time.Now()
 	player.Color = newColor
 	
 	// Update persistent user data
@@ -404,6 +412,25 @@ func (s *Server) broadcastColorChanged(playerID uint32, color string) {
 	s.mutex.RUnlock()
 }
 
+func (s *Server) handleHeartbeat(data []byte, addr *net.UDPAddr) {
+	playerID, ok := DecodeHeartbeatPacket(data)
+	if !ok {
+		return
+	}
+
+	s.mutex.Lock()
+	player, exists := s.players[playerID]
+	if !exists {
+		s.mutex.Unlock()
+		return
+	}
+
+	// Update the player's address and last seen time
+	player.Address = addr
+	player.LastSeen = time.Now()
+	s.mutex.Unlock()
+}
+
 func (s *Server) checkTimeouts() {
 	s.mutex.Lock()
 	defer s.mutex.Unlock()
diff --git a/server/players.json b/server/players.json
index fdb0455..c5a26b5 100644
--- a/server/players.json
+++ b/server/players.json
@@ -1,20 +1,29 @@
 {
+  "foo": {
+    "username": "foo",
+    "color": "orange",
+    "position": {
+      "X": -25.698553,
+      "Y": 4.9015007,
+      "Z": 39.29553
+    }
+  },
   "sky": {
     "username": "sky",
     "color": "purple",
     "position": {
-      "X": 3.9765263,
-      "Y": -5.033655,
-      "Z": 19.824585
+      "X": 5.9400105,
+      "Y": -0.055064563,
+      "Z": -3.896852
     }
   },
   "test": {
     "username": "test",
     "color": "red",
     "position": {
-      "X": 14.141681,
-      "Y": 2.2383373,
-      "Z": -0.06184849
+      "X": 2.1930797,
+      "Y": -0.08324346,
+      "Z": -1.550154
     }
   }
 }
\ No newline at end of file