Can* API functions by Yota's request.

Content.Server/GameObjects/Components/Items/InventoryComponent.cs

@@ -45,10 +45,15 @@ namespace Content.Server.Interfaces.GameObjects
             return slots[slot];
         }
 
-        public bool PutInSlot(string slot, IItemComponent item)
+        public bool Insert(string slot, IItemComponent item)
         {
+            if (item == null)
+            {
+                throw new ArgumentNullException(nameof(item), "An item must be passed. To remove an item from a slot, use Drop()");
+            }
+
             var inventorySlot = _GetSlot(slot);
-            if (inventorySlot.Item != null)
+            if (!CanInsert(slot, item))
             {
                 return false;
             }
@@ -58,11 +63,22 @@ namespace Content.Server.Interfaces.GameObjects
             return true;
         }
 
-        public bool DropSlot(string slot)
+        public bool CanInsert(string slot, IItemComponent item)
         {
+            var inventorySlot = _GetSlot(slot);
+            return inventorySlot.Item == null;
+        }
+
+        public bool Drop(string slot)
+        {
+            if (!CanDrop(slot))
+            {
+                return false;
+            }
+
             var inventorySlot = _GetSlot(slot);
             var item = inventorySlot.Item;
-            if (item == null || !container.Remove(item.Owner))
+            if (!container.Remove(item.Owner))
             {
                 return false;
             }
@@ -76,17 +92,42 @@ namespace Content.Server.Interfaces.GameObjects
             return true;
         }
 
+        public bool CanDrop(string slot)
+        {
+            var inventorySlot = _GetSlot(slot);
+            var item = inventorySlot.Item;
+            return item != null && container.CanRemove(item.Owner);
+        }
+
         public void AddSlot(string slot)
         {
-            if (slots.ContainsKey(slot))
+            if (HasSlot(slot))
             {
-
+                throw new InvalidOperationException($"Slot '{slot}' already exists.");
             }
+
+            slots[slot] = new InventorySlot(slot, this);
         }
 
         public void RemoveSlot(string slot)
         {
-            throw new NotImplementedException();
+            if (!HasSlot(slot))
+            {
+                throw new InvalidOperationException($"Slow '{slot}' does not exist.");
+            }
+
+            if (Get(slot) != null && !Drop(slot))
+            {
+                // TODO: Handle this potential failiure better.
+                throw new InvalidOperationException("Unable to remove slot as the contained item could not be dropped");
+            }
+
+            slots.Remove(slot);
+        }
+
+        public bool HasSlot(string slot)
+        {
+            return slots.ContainsKey(slot);
         }
 
         private class InventorySlot : IInventorySlot

Content.Server/Interfaces/GameObjects/Components/Items/IHandsComponent.cs

@@ -40,11 +40,35 @@ namespace Content.Server.Interfaces.GameObjects
         /// <returns>True if the item was inserted into a hand, false otherwise.</returns>
         bool PutInHand(IItemComponent item, string index, bool fallback=true);
 
+        /// <summary>
+        ///     Checks to see if an item can be put in any hand.
+        /// </summary>
+        /// <param name="item">The item to check for.</param>
+        /// <returns>True if the item can be inserted, false otherwise.</returns>
+        bool CanPutInHand(IItemComponent item);
+
+        /// <summary>
+        ///     Checks to see if an item can be put in the specified hand.
+        /// </summary>
+        /// <param name="item">The item to check for.</param>
+        /// <param name="index">The index for the hand to check for.</param>
+        /// <returns>True if the item can be inserted, false otherwise.</returns>
+        bool CanPutInHand(IItemComponent item, string index);
+
         /// <summary>
         ///     Drops an item on the ground, removing it from the hand.
         /// </summary>
         /// <param name="index">The hand to drop from.</param>
         /// <returns>True if an item was successfully dropped, false otherwise.</returns>
         bool Drop(string index);
+
+        /// <summary>
+        ///     Checks whether the item in the specified hand can be dropped.
+        /// </summary>
+        /// <param name="index">The hand to check for.</param>
+        /// <returns>
+        ///     True if the item can be dropped, false if the hand is empty or the item in the hand cannot be dropped.
+        /// </returns>
+        bool CanDrop(string index);
     }
 }

Content.Server/Interfaces/GameObjects/Components/Items/IInventoryComponent.cs

@@ -29,14 +29,31 @@ namespace Content.Server.Interfaces.GameObjects
         /// <param name="slot">The slot to put the item in.</param>
         /// <param name="item">The item to insert into the slot.</param>
         /// <returns>True if the item was successfully inserted, false otherwise.</returns>
-        bool PutInSlot(string slot, IItemComponent item);
+        bool Insert(string slot, IItemComponent item);
+
+        /// <summary>
+        ///     Checks whether an item can be put in the specified slot.
+        /// </summary>
+        /// <param name="slot">The slot to check for.</param>
+        /// <param name="item">The item to check for.</param>
+        /// <returns>True if the item can be inserted into the specified slot.</returns>
+        bool CanInsert(string slot, IItemComponent item);
 
         /// <summary>
         ///     Drops the item in a slot.
         /// </summary>
         /// <param name="slot">The slot to drop the item from.</param>
         /// <returns>True if an item was dropped, false otherwise.</returns>
-        bool DropSlot(string slot);
+        bool Drop(string slot);
+
+        /// <summary>
+        ///     Checks whether an item can be dropped from the specified slot.
+        /// </summary>
+        /// <param name="slot">The slot to check for.</param>
+        /// <returns>
+        ///     True if there is an item in the slot and it can be dropped, false otherwise.
+        /// </returns>
+        bool CanDrop(string slot);
 
         /// <summary>
         ///     Adds a new slot to this inventory component.
@@ -57,10 +74,10 @@ namespace Content.Server.Interfaces.GameObjects
         void RemoveSlot(string slot);
 
         /// <summary>
-        ///
+        ///     Checks whether a slot with the specified name exists.
         /// </summary>
-        /// <param name="slot"></param>
-        /// <returns></returns>
+        /// <param name="slot">The slot name to check.</param>
+        /// <returns>True if the slot exists, false otherwise.</returns>
         bool HasSlot(string slot);
     }