diff --git a/.idea/dictionaries/project.xml b/.idea/dictionaries/project.xml
index d602d26..2d6270d 100644
--- a/.idea/dictionaries/project.xml
+++ b/.idea/dictionaries/project.xml
@@ -2,6 +2,7 @@
   <dictionary name="project">
     <words>
       <w>mintime</w>
+      <w>wsock</w>
     </words>
   </dictionary>
 </component>
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index bca5f85..f527e11 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -26,5 +26,9 @@ target_link_libraries(server01 PRIVATE wsock32 ws2_32 json-c::json-c)
 
 add_executable(server02 server02.c server02.h ${COMMON_SOURCES})
 target_link_libraries(server02 wsock32 ws2_32)
+
 add_executable(server03 server03.c server03.h ${COMMON_SOURCES})
-target_link_libraries(server03 wsock32 ws2_32)
\ No newline at end of file
+target_link_libraries(server03 wsock32 ws2_32)
+
+add_executable(server04 server04.c server04.h ${COMMON_SOURCES})
+target_link_libraries(server04 wsock32 ws2_32)
\ No newline at end of file
diff --git a/data.c b/data.c
index 196cdf9..f25d45e 100644
--- a/data.c
+++ b/data.c
@@ -13,7 +13,25 @@ SOCKET get_listen_socket() {
     SOCKADDR_IN serverAddr;
 
     WSAStartup(MAKEWORD(2,0), &WSAData);
-    SOCKET server = socket(AF_INET, SOCK_STREAM, 0);
+    SOCKET server = socket(AF_INET, SOCK_STREAM, 0 );
+
+    serverAddr.sin_addr.s_addr = INADDR_ANY;
+    serverAddr.sin_family = AF_INET;
+    serverAddr.sin_port = htons(PORT);
+
+    bind(server, (SOCKADDR *)&serverAddr, sizeof(serverAddr));
+    listen(server, 0);
+    return server;
+}
+
+
+SOCKET get_listen_socket_udp() {
+    WSADATA WSAData;
+
+    SOCKADDR_IN serverAddr;
+
+    WSAStartup(MAKEWORD(2,2), &WSAData);
+    SOCKET server = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 
     serverAddr.sin_addr.s_addr = INADDR_ANY;
     serverAddr.sin_family = AF_INET;
diff --git a/data.h b/data.h
index e11436c..2c6cc68 100644
--- a/data.h
+++ b/data.h
@@ -35,4 +35,5 @@ uint8_t *byte_array_get_bytes(byte_array_t *array, size_t length);
 void byte_array_shift_bytes(byte_array_t *array, size_t length);
 
 
-SOCKET get_listen_socket();
\ No newline at end of file
+SOCKET get_listen_socket();
+SOCKET get_listen_socket_udp();
\ No newline at end of file
diff --git a/server04.c b/server04.c
new file mode 100644
index 0000000..25c1698
--- /dev/null
+++ b/server04.c
@@ -0,0 +1,125 @@
+//
+// Created by PeterDwyer on 30/07/2025.
+//
+
+#include "server04.h"
+#include <pthread.h>
+#include <winsock2.h>
+#include <stdio.h>
+#include "data.h"
+#include <stdbool.h>
+#include <inaddr.h>
+
+#define BUF_SIZE 1024
+
+int main() {
+    const SOCKET server = get_listen_socket_udp();
+    SOCKADDR_IN clientAddr;
+    SOCKET client;
+    int clientAddrSize = sizeof(clientAddr);
+    int connection_number = 1;
+    char *request = malloc(BUF_SIZE);
+    char buffer[BUF_SIZE] = {0};
+    int bytesReceived;
+    data_map_t *data = data_map_create(1024);
+    printf("Listening for incoming connections...\n");
+    while ((bytesReceived = recvfrom(server, buffer, sizeof(buffer), 0, (SOCKADDR *) &clientAddr, &clientAddrSize)) > 0) {
+        const char *equals = "=";
+        size_t pos;
+        // IN_ADDR addr = clientAddr.sin_addr;
+        // printf("{%d} Client ip: |%d.%d.%d.%d| \n", connection_number, addr.S_un.S_un_b.s_b1, addr.S_un.S_un_b.s_b2, addr.S_un.S_un_b.s_b3, addr.S_un.S_un_b.s_b4);
+        // printf("{%d} Client port: |%d| \n", connection_number, clientAddr.sin_port);
+        if ((pos = strcspn(buffer, equals)) >= 0) {
+            key_value_t *kv = malloc(sizeof(key_value_t));
+            strncpy_s(kv->key, BUF_SIZE, buffer, pos);
+            strncpy_s(kv->value, BUF_SIZE, buffer + sizeof(char)*(pos+1), sizeof(buffer) - pos - 1);
+            data_map_insert_kv(data, kv);
+            printf("{%d} Key: |%s| Value: |%s| \n", connection_number, kv->key, kv->value);
+        } else {
+            printf("{%d} Client sent: |%s| \n", connection_number, buffer);
+        }
+        sendto(server, buffer, bytesReceived, 0, (SOCKADDR *) &clientAddr, clientAddrSize);
+        strncpy_s(request, BUF_SIZE, buffer, bytesReceived);
+        printf("{%d} Client sent: |%s| \n", connection_number, request);
+        connection_number++;
+    }
+    data_map_free(data);
+    free(request);
+    return 0;
+}
+
+data_map_t *data_map_create(const int capacity) {
+    data_map_t *map = malloc(sizeof(data_map_t));
+    map->capacity = capacity;
+    map->count = 0;
+    map->data = calloc(capacity, sizeof(key_value_t));
+    return map;
+}
+void data_map_free(data_map_t *map) {
+    for (int i = 0; i < map->count; i++) {
+        free(map->data[i].key);
+        free(map->data[i].value);
+    }
+    free(map->data);
+    free(map);
+}
+void data_map_insert_kv(data_map_t *map, key_value_t *kv) {
+    if (map->data == NULL) {
+        exit(1);
+    }
+    for (int i = 0; i < map->count; i++) {
+        if (strcmp(map->data[i].key, kv->key) == 0) {
+            map->data[i].value = kv->value;
+            return;
+        }
+    }
+    const size_t new_size = map->count + 1;
+    if (new_size > map->capacity) {
+        map->capacity = map->capacity+1024;
+        key_value_t *new_array = realloc(map->data, map->capacity * sizeof(key_value_t));
+        map->data = new_array;
+    }
+    map->data[map->count].key = kv->key;
+    map->data[map->count].value = kv->value;
+    map->count = new_size;
+}
+
+void data_map_append(data_map_t *map, char *key, char *value) {
+    if (map->data == NULL) {
+        exit(1);
+    }
+    const size_t new_size = map->count + 1;
+    if (new_size > map->capacity) {
+        map->capacity = map->capacity+1024;
+        key_value_t *new_array = realloc(map->data, map->capacity * sizeof(key_value_t));
+        map->data = new_array;
+        if (map->data == NULL) {
+            printf("Failed to allocate memory for array\n");
+        }
+    }
+    map->data[map->count].key = key;
+    map->data[map->count].value = value;
+    map->count = new_size;
+}
+
+void data_map_insert(data_map_t *map, char *key, char *value) {
+    if (map->data == NULL) {
+        exit(1);
+    }
+    for (int i = 0; i < map->count; i++) {
+        if (strcmp(map->data[i].key, key) == 0) {
+            map->data[i].value = value;
+            return;
+        }
+    }
+    data_map_append(map, key, value);
+}
+
+char *data_map_get(data_map_t *map, const char *key) {
+    for (int i = 0; i < map->count; i++) {
+        if (strcmp(map->data[i].key, key) == 0) {
+            return map->data[i].value;
+        }
+    }
+    return NULL;
+}
\ No newline at end of file
diff --git a/server04.h b/server04.h
new file mode 100644
index 0000000..213cf06
--- /dev/null
+++ b/server04.h
@@ -0,0 +1,28 @@
+//
+// Created by PeterDwyer on 30/07/2025.
+//
+
+#ifndef SERVER04_H
+#define SERVER04_H
+#include <stddef.h>
+
+#endif //SERVER04_H
+
+typedef struct KeyValue {
+    char *key;
+    char *value;
+}key_value_t;
+
+typedef struct DataMap {
+    size_t capacity;
+    size_t count;
+    key_value_t *data;
+} data_map_t;
+
+
+data_map_t *data_map_create(int capacity);
+void data_map_free(data_map_t *map);
+void data_map_append(data_map_t *map, char *key, char *value);
+void data_map_insert(data_map_t *map, char *key, char *value);
+void data_map_insert_kv(data_map_t *map, key_value_t *kv);
+char *data_map_get(data_map_t *map, const char *key);
diff --git a/server04_database_client_test_suite.py b/server04_database_client_test_suite.py
new file mode 100644
index 0000000..2b067cb
--- /dev/null
+++ b/server04_database_client_test_suite.py
@@ -0,0 +1,203 @@
+import socket
+import threading
+import time
+import random
+from typing import Optional, Dict, List, Tuple
+
+class DatabaseTestClient:
+    def __init__(self, host: str = 'localhost', server_port: int = 40000):
+        self.host = host
+        self.server_port = server_port
+        self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        # Bind to any available interface (empty string) on an ephemeral port (0)
+        self.sock.bind(('', 0))
+        # Get the actual port assigned
+        self.client_port = self.sock.getsockname()[1]
+        self.sock.settimeout(1.0)  # 1 second timeout for receives
+        print(f"Client bound to port {self.client_port}")
+
+    def send_insert(self, key: str, value: str) -> None:
+        """Send an insert request."""
+        message = f"{key}={value}"
+        if len(message) >= 1000:
+            raise ValueError("Message too long")
+        self.sock.sendto(message.encode(), (self.host, self.server_port))
+
+    def send_retrieve(self, key: str) -> Optional[str]:
+        """Send a retrieve request and return the response."""
+        if len(key) >= 1000:
+            raise ValueError("Key too long")
+        self.sock.sendto(key.encode(), (self.host, self.server_port))
+        
+        try:
+            data, addr = self.sock.recvfrom(1000)  # Changed from recvmsg to recvfrom
+            return data.decode()
+        except socket.timeout:
+            return None
+
+    def close(self):
+        self.sock.close()
+
+def run_basic_tests(client: DatabaseTestClient) -> List[Tuple[str, bool, str]]:
+    """Run basic functionality tests."""
+    results = []
+    
+    # Test 1: Basic insert and retrieve
+    client.send_insert("test1", "value1")
+    time.sleep(0.1)  # Give server time to process
+    response = client.send_retrieve("test1")
+    results.append(("Basic insert/retrieve", 
+                   response == "test1=value1",
+                   f"Expected 'test1=value1', got '{response}'"))
+
+    # Test 2: Update existing key
+    client.send_insert("test1", "value2")
+    time.sleep(0.1)
+    response = client.send_retrieve("test1")
+    results.append(("Update existing key",
+                   response == "test1=value2",
+                   f"Expected 'test1=value2', got '{response}'"))
+
+    # Test 3: Empty key
+    client.send_insert("", "empty_key_value")
+    time.sleep(0.1)
+    response = client.send_retrieve("")
+    results.append(("Empty key",
+                   response == "=empty_key_value",
+                   f"Expected '=empty_key_value', got '{response}'"))
+
+    # Test 4: Empty value
+    client.send_insert("empty_value", "")
+    time.sleep(0.1)
+    response = client.send_retrieve("empty_value")
+    results.append(("Empty value",
+                   response == "empty_value=",
+                   f"Expected 'empty_value=', got '{response}'"))
+
+    # Test 5: Version check
+    response = client.send_retrieve("version")
+    results.append(("Version check",
+                   response is not None and response.startswith("version=") and len(response) > 8,
+                   f"Version response invalid: '{response}'"))
+
+    # Test 6: Version modification attempt
+    client.send_insert("version", "HACKED")
+    time.sleep(0.1)
+    response = client.send_retrieve("version")
+    results.append(("Version modification prevention",
+                   response is not None and not response.endswith("HACKED"),
+                   f"Version should not be modifiable, got: '{response}'"))
+
+    return results
+
+def run_edge_case_tests(client: DatabaseTestClient) -> List[Tuple[str, bool, str]]:
+    """Run edge case tests."""
+    results = []
+
+    # Test 1: Key with multiple equals signs
+    client.send_insert("multi=equals", "value=with=equals")
+    time.sleep(0.1)
+    response = client.send_retrieve("multi=equals")
+    results.append(("Multiple equals in key",
+                   response is None or not response.startswith("multi=equals"),
+                   "Key with equals sign should not be stored"))
+
+    # Test 2: Value with equals signs
+    client.send_insert("test2", "value=with=equals")
+    time.sleep(0.1)
+    response = client.send_retrieve("test2")
+    results.append(("Equals in value",
+                   response == "test2=value=with=equals",
+                   f"Expected 'test2=value=with=equals', got '{response}'"))
+
+    # Test 3: Non-existent key
+    response = client.send_retrieve("nonexistent")
+    results.append(("Non-existent key",
+                   response is None or response == "nonexistent=",
+                   f"Expected None or 'nonexistent=', got '{response}'"))
+
+    return results
+
+def run_concurrent_tests(num_clients: int = 5) -> List[Tuple[str, bool, str]]:
+    """Run concurrent access tests."""
+    results = []
+    clients = [DatabaseTestClient() for _ in range(num_clients)]
+    
+    def concurrent_ops(client_id: int):
+        client = clients[client_id]
+        key = f"concurrent_{client_id}"
+        for i in range(10):
+            value = f"value_{i}"
+            client.send_insert(key, value)
+            time.sleep(0.05)
+            response = client.send_retrieve(key)
+            if response != f"{key}={value}":
+                results.append((f"Concurrent client {client_id}",
+                              False,
+                              f"Expected '{key}={value}', got '{response}'"))
+                return
+        results.append((f"Concurrent client {client_id}",
+                       True,
+                       "All operations successful"))
+
+    threads = [threading.Thread(target=concurrent_ops, args=(i,))
+               for i in range(num_clients)]
+    
+    for thread in threads:
+        thread.start()
+    
+    for thread in threads:
+        thread.join()
+
+    for client in clients:
+        client.close()
+
+    return results
+
+def main():
+    # MESSAGE = "Hello, UDP!"
+    # sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # UDP
+    # sock.sendto(bytes(MESSAGE, "utf-8"), ("localhost", 40000))
+    # quit()
+    # Allow command line arguments for host and port
+    import argparse
+    parser = argparse.ArgumentParser(description='Test UDP Database Server')
+    parser.add_argument('--host', default='localhost', help='Server host')
+    parser.add_argument('--port', type=int, default=40000, help='Server port')
+    args = parser.parse_args()
+
+    print(f"Starting Unusual Database Program Tests on {args.host}:{args.port}\n")
+
+    client = DatabaseTestClient(args.host, args.port)
+    # ... rest of the main function remains the same ...
+
+    print("Running basic functionality tests...")
+    basic_results = run_basic_tests(client)
+    
+    print("\nRunning edge case tests...")
+    edge_results = run_edge_case_tests(client)
+    
+    client.close()
+
+    print("\nRunning concurrent access tests...")
+    concurrent_results = run_concurrent_tests()
+
+    # Print results
+    all_results = basic_results + edge_results + concurrent_results
+    passed = sum(1 for _, success, _ in all_results if success)
+    total = len(all_results)
+
+    print("\nTest Results:")
+    print("=" * 60)
+    for test_name, success, message in all_results:
+        status = "✓" if success else "✗"
+        print(f"{status} {test_name}")
+        if not success:
+            print(f"   {message}")
+    
+    print("\nSummary:")
+    print(f"Passed: {passed}/{total} tests")
+    print(f"Success rate: {(passed/total)*100:.1f}%")
+
+if __name__ == "__main__":
+    main()
\ No newline at end of file