diff --git a/web-api/Controllers/ContactsController.cs b/web-api/Controllers/ContactsController.cs
index 76c8debe..b476a3c3 100644
--- a/web-api/Controllers/ContactsController.cs
+++ b/web-api/Controllers/ContactsController.cs
@@ -12,6 +12,12 @@ public class ContactsController : ControllerBase
 {
     private readonly IUsersService _usersService;
     private readonly IChatsService _chatsService;
+    private readonly HttpClient _httpClient = new HttpClient();
+
+    private readonly JsonSerializerOptions _jsonSerializerOptions = new JsonSerializerOptions
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
+    };
 
     public ContactsController(IUsersService usersService, IChatsService chatsService)
     {
@@ -73,10 +79,10 @@ public IActionResult SignUp([FromBody] JsonElement body)
         }
 
         // Create new user
-        User newUser = new User(username, name, "localhost", password, profilePicture);
+        var newUser = new User(username, name, "localhost", password, profilePicture);
         _usersService.Add(newUser);
 
-        return Ok();
+        return Created("", null);
     }
 
 
@@ -91,8 +97,8 @@ public IActionResult Get()
             return NotFound();
         }
 
-        List<string> contacsIds = currentUser.Chats.Keys.ToList();
-        return Ok(_usersService.Get(contacsIds));
+        List<string> contactsIds = currentUser.Chats.Keys.ToList();
+        return Ok(_usersService.Get(contactsIds));
     }
 
     [HttpPost]
@@ -165,10 +171,14 @@ public IActionResult Post([FromBody] JsonElement body)
         }
         else
         {
-            // TODO: add new chat to contact on a remote server
+            // Send an invitation to the contact on the remote server
+            var invitation = new Invitation(currentUser.Username, contact.Username, "localhost");
+            var json = JsonSerializer.Serialize(invitation, _jsonSerializerOptions);
+            var stringContent = new StringContent(json, System.Text.Encoding.UTF8, "application/json");
+            _httpClient.PostAsync("https://" + contact.Server + "/api/invitations", stringContent).Wait();
         }
 
-        return Ok();
+        return Created("", null);
     }
 
     [HttpGet("{id}")]
@@ -264,7 +274,7 @@ public IActionResult Put(string id, [FromBody] JsonElement body)
             return NotFound();
         }
 
-        return Ok();
+        return NoContent();
     }
 
     [HttpDelete("{id}")]
@@ -303,7 +313,7 @@ public IActionResult Delete(string id)
         // Delete the currentUser from the contact
         contact.Chats.Remove(currentUser.Username);
         _usersService.Update(contact);
-        return Ok();
+        return NoContent();
     }
 
     [HttpGet("{id}/messages")]
@@ -383,11 +393,14 @@ public IActionResult PostNewMessage(string id, [FromBody] string content)
         // Add the new message to the contact if on a remote server
         if (contact.Server != "localhost")
         {
-            // TODO: add new message to contact on a remote server
             // Send transfer request
+            var transfer = new Transfer(currentUser.Username, contact.Username, content);
+            var json = JsonSerializer.Serialize(transfer, _jsonSerializerOptions);
+            var stringContent = new StringContent(json, System.Text.Encoding.UTF8, "application/json");
+            _httpClient.PostAsync("https://" + contact.Server + "/api/transfer", stringContent).Wait();
         }
 
-        return Ok();
+        return Created("", null);
     }
 
     [HttpGet("{id}/messages/{id2}")]
@@ -468,13 +481,9 @@ public IActionResult PutMessage(string id, int id2, [FromBody] string content)
         // Update the chat
         Chat chat = currentUser.Chats[id];
         _chatsService.Update(chat);
-        // Update the contact if on a remote server
-        if (contact.Server != "localhost")
-        {
-            // TODO: update message on a remote server
-        }
+        // No API exists for updating the contact if on a remote server
 
-        return Ok();
+        return NoContent();
     }
 
     [HttpDelete("{id}/messages/{id2}")]
@@ -516,12 +525,7 @@ public IActionResult DeleteMessage(string id, int id2)
         Chat chat = currentUser.Chats[id];
         chat.Messages.Remove(message);
         _chatsService.Update(chat);
-        // Delete the message from the contact if on a remote server
-        if (contact.Server != "localhost")
-        {
-            // TODO: delete message from contact on a remote server
-        }
-
-        return Ok();
+        // No API exists for deleting a message from the contact if on a remote server
+        return NoContent();
     }
 }
\ No newline at end of file
diff --git a/web-api/Controllers/InvitationController.cs b/web-api/Controllers/InvitationController.cs
index 67f3acc8..4276dab0 100644
--- a/web-api/Controllers/InvitationController.cs
+++ b/web-api/Controllers/InvitationController.cs
@@ -53,6 +53,6 @@ public IActionResult Post([FromBody] Invitation invitation)
             _usersService.Update(remoteUser);
         }
 
-        return Ok();
+        return Created("", null);
     }
 }
\ No newline at end of file
diff --git a/web-api/Controllers/TransferController.cs b/web-api/Controllers/TransferController.cs
index 40f70597..23bc0839 100644
--- a/web-api/Controllers/TransferController.cs
+++ b/web-api/Controllers/TransferController.cs
@@ -41,6 +41,6 @@ public IActionResult Post([FromBody] Transfer transfer)
         chat.Messages.Add(message);
         _chatsService.Update(chat);
 
-        return Ok();
+        return Created("", null);
     }
 }
\ No newline at end of file