diff --git a/src/main/java/org/fungover/haze/HazeDatabase.java b/src/main/java/org/fungover/haze/HazeDatabase.java
index e21d6bc8..cf7b2aef 100644
--- a/src/main/java/org/fungover/haze/HazeDatabase.java
+++ b/src/main/java/org/fungover/haze/HazeDatabase.java
@@ -58,14 +58,19 @@ public String exists(String key) {
 		return "";
 	}
 
-	public String setNX(String key) {
+	public String setNX(String key, String value) {
+		String replyWhenKeyNotSet = ":0\r\n";
+		String replyWhenKeySet = ":1\r\n";
 		lock.lock();
 		try {
-			//sets value if key does not exists, if there is a key this operation is ignored.
+			if(database.containsKey(key))
+				return replyWhenKeyNotSet;
+			else{
+				database.put(key, value);
+				return replyWhenKeySet;
+			}
 		} finally {
 			lock.unlock();
-
 		}
-		return "";
 	}
 }
diff --git a/src/main/java/org/fungover/haze/Main.java b/src/main/java/org/fungover/haze/Main.java
index 85c41a8f..370f4c87 100644
--- a/src/main/java/org/fungover/haze/Main.java
+++ b/src/main/java/org/fungover/haze/Main.java
@@ -4,10 +4,16 @@
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.net.ServerSocket;
+import java.net.Socket;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
 
 public class Main {
 	public static void main(String[] args) {
 
+		HazeDatabase hazeDatabase = new HazeDatabase();
+
 		try (ServerSocket serverSocket = new ServerSocket(6379)) {
 			while (true) {
 				var client = serverSocket.accept();
@@ -16,18 +22,17 @@ public static void main(String[] args) {
 					try {
 
 
-						BufferedReader input = new BufferedReader(new InputStreamReader(client.getInputStream()));
-						System.out.println(input.readLine());
-						System.out.println(input.readLine());
-						System.out.println(input.readLine());
-						System.out.println(input.readLine());
-						System.out.println(input.readLine());
+                        BufferedReader input = new BufferedReader(new InputStreamReader(client.getInputStream()));
+                        List<String> inputList = new ArrayList<>();
 
+                        String firstReading = input.readLine();
+                        readInputStream(input, inputList, firstReading);
 
-						printThreadDebug();
+				        executeCommand(hazeDatabase, client, inputList);
 
+				        inputList.forEach(System.out::println); // For checking incoming message
 
-						client.getOutputStream().write("+OK\r\n".getBytes());
+						printThreadDebug();
 
 						client.close();
 
@@ -36,12 +41,9 @@ public static void main(String[] args) {
 					}
 				};
 				Thread.startVirtualThread(newThread);
-
 			}
 		} catch (IOException e) {
 			throw new RuntimeException(e);
-
-
 		}
 	}
 
@@ -49,4 +51,36 @@ private static void printThreadDebug() {
 		System.out.println("ThreadID " + Thread.currentThread().threadId());  // Only for Debug
 		System.out.println("Is virtual Thread " + Thread.currentThread().isVirtual()); // Only for Debug
 	}
+
+	private static void executeCommand(HazeDatabase hazeDatabase, Socket client, List<String> inputList) throws IOException {
+		String command = inputList.get(0);
+		String key = inputList.get(1);
+		String value = getValueIfExist(inputList);
+
+		switch (command) {
+			case "SETNX" -> client.getOutputStream().write(hazeDatabase.setNX(key, value).getBytes());
+			default -> client.getOutputStream().write("-ERR unknown command\r\n".getBytes());
+		}
+	}
+
+	private static String getValueIfExist(List<String> inputList) {
+		if (inputList.size() == 3)
+			return inputList.get(2);
+		return "";
+	}
+
+	private static void readInputStream(BufferedReader input, List<String> inputList, String firstReading) throws IOException {
+		int size;
+		if (firstReading.startsWith("*")) {
+			size = Integer.parseInt(firstReading.substring(1)) * 2;
+			for (int i = 0; i < size; i++) {
+				String temp = input.readLine();
+				if (!temp.contains("$"))
+					inputList.add(temp);
+			}
+		} else {
+			String[] seperated = firstReading.split("\\s");
+			inputList.addAll(Arrays.asList(seperated));
+		}
+	}
 }
diff --git a/src/test/java/org/fungover/haze/HazeDatabaseTest.java b/src/test/java/org/fungover/haze/HazeDatabaseTest.java
new file mode 100644
index 00000000..98d4b7b5
--- /dev/null
+++ b/src/test/java/org/fungover/haze/HazeDatabaseTest.java
@@ -0,0 +1,21 @@
+package org.fungover.haze;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class HazeDatabaseTest {
+
+	HazeDatabase testDatabase = new HazeDatabase();
+
+	@Test
+	void testSetNxReturnZeroWhenExistingKeyAreUsedWithDifferentValue() {
+		testDatabase.setNX("1", "Hej");
+		assertThat(testDatabase.setNX("1", "Då")).isEqualTo(":0\r\n");
+	}
+
+	@Test
+	void testSetNxReturnOneWhenKeyDontExist() {
+		assertThat(testDatabase.setNX("2", "Då")).isEqualTo(":1\r\n");
+	}
+}