upd

Code/Inventory/Usable/UseableBase.cs

@@ -6,11 +6,38 @@ public abstract class UseableBase : Component, IUseable
 {
 	[Property] public float Cooldown { get; set; } = 0.5f;
 
-	private TimeSince _timeSinceUsed;
+	private bool _equipped;
 
-	protected override void OnStart()
+	[Property]
+	public bool Equipped
+	{
+		get => _equipped;
+		set
+		{
+			if ( _equipped != value )
+			{
+				_equipped = value;
+				if ( _equipped )
+				{
+					OnEquip?.Invoke();
+				}
+			}
+		}
+	}
+
+	private TimeSince _timeSinceUsed;
+	public Action OnEquip { get; set; }
+
+	protected override void OnAwake()
 	{
 		_timeSinceUsed = Cooldown;
+
+		OnEquip += OnEquipped;
+	}
+
+	public virtual void OnEquipped()
+	{
+		Log.Info( $"OnEquip {this}" );
 	}
 
 	public virtual bool CanUse()