diff --git a/Examples/NodeToy/NodeGraphExample.asset b/Examples/NodeToy/NodeGraphExample.asset
index c44ea50..7fa3bac 100644
Binary files a/Examples/NodeToy/NodeGraphExample.asset and b/Examples/NodeToy/NodeGraphExample.asset differ
diff --git a/Scripts/Node.cs b/Scripts/Node.cs
index d563231..1963d3b 100644
--- a/Scripts/Node.cs
+++ b/Scripts/Node.cs
@@ -26,6 +26,40 @@ public abstract class Node : ScriptableObject {
         Init();
     }
 
+
+    /// <summary> Checks all connections for invalid references, and removes them. </summary>
+    public void VerifyConnections() {
+        for (int i = 0; i < InputCount; i++) {
+            inputs[i].VerifyConnections();
+        }
+        for (int i = 0; i < OutputCount; i++) {
+            outputs[i].VerifyConnections();
+        }
+    }
+
+    /// <summary> Returns input or output port which matches fieldName </summary>
+    public NodePort GetPortByFieldName(string fieldName) {
+        NodePort port = GetOutputByFieldName(fieldName);
+        if (port != null) return port;
+        else return GetInputByFieldName(fieldName);
+    }
+
+    /// <summary> Returns output port which matches fieldName </summary>
+    public NodePort GetOutputByFieldName(string fieldName) {
+        for (int i = 0; i < OutputCount; i++) {
+            if (outputs[i].fieldName == fieldName) return outputs[i];
+        }
+        return null;
+    }
+
+    /// <summary> Returns input port which matches fieldName </summary>
+    public NodePort GetInputByFieldName(string fieldName) {
+        for (int i = 0; i < InputCount; i++) {
+            if (inputs[i].fieldName == fieldName) return inputs[i];
+        }
+        return null;
+    }
+
     /// <summary> Initialize node. Called on creation. </summary>
     protected virtual void Init() { name = GetType().Name; }
 
@@ -48,13 +82,6 @@ public abstract class Node : ScriptableObject {
         return -1;
     }
 
-    public NodePort CreateNodeInput(string name, Type type) {
-        return new NodePort(name, type, this, NodePort.IO.Input);
-    }
-    public NodePort CreateNodeOutput(string name, Type type) {
-        return new NodePort(name, type, this, NodePort.IO.Output);
-    }
-
     public void ClearConnections() {
         for (int i = 0; i < inputs.Count; i++) {
             inputs[i].ClearConnections();
@@ -96,8 +123,8 @@ public abstract class Node : ScriptableObject {
                 else if (attribs[k] is OutputAttribute) outputAttrib = attribs[k] as OutputAttribute;
             }
             if (inputAttrib != null && outputAttrib != null) Debug.LogError("Field " + fieldInfo + " cannot be both input and output.");
-            else if (inputAttrib != null) inputPorts.Add(new NodePort(fieldInfo[i].Name, fieldInfo[i].FieldType, this, NodePort.IO.Input));
-            else if (outputAttrib != null) outputPorts.Add(new NodePort(fieldInfo[i].Name, fieldInfo[i].FieldType, this, NodePort.IO.Output));
+            else if (inputAttrib != null) inputPorts.Add(new NodePort(fieldInfo[i], this));
+            else if (outputAttrib != null) outputPorts.Add(new NodePort(fieldInfo[i], this));
         }
 
         inputs = inputPorts;
diff --git a/Scripts/NodeGraph.cs b/Scripts/NodeGraph.cs
index d61ec99..9e3c7d8 100644
--- a/Scripts/NodeGraph.cs
+++ b/Scripts/NodeGraph.cs
@@ -44,6 +44,14 @@ public abstract class NodeGraph : ScriptableObject, ISerializationCallbackReceiv
         for (int i = 0; i < nodes.Count; i++) {
             nodes[i].graph = this;
         }
+        VerifyConnections();
+    }
+
+    /// <summary> Checks all connections for invalid references, and removes them. </summary>
+    public void VerifyConnections() {
+        for (int i = 0; i < nodes.Count; i++) {
+            nodes[i].VerifyConnections();
+        }
     }
 }
 
diff --git a/Scripts/NodePort.cs b/Scripts/NodePort.cs
index c0df2bb..937c0d1 100644
--- a/Scripts/NodePort.cs
+++ b/Scripts/NodePort.cs
@@ -2,10 +2,11 @@
 using System.Collections.Generic;
 using UnityEngine;
 using System;
+using System.Reflection;
 
 [Serializable]
 public class NodePort {
-    public enum IO { Input, Output}
+    public enum IO { Input, Output }
 
     public int ConnectionCount { get { return connections.Count; } }
     /// <summary> Return the first connection </summary>
@@ -18,24 +19,40 @@ public class NodePort {
     public bool IsOutput { get { return direction == IO.Output; } }
 
     public Node node { get; private set; }
-    public string name { get { return _name; } }
+    [SerializeField] public string name;
     public bool enabled { get { return _enabled; } set { _enabled = value; } }
-    public string id { get { return _id; } }
+    public string fieldName { get { return _fieldName; } }
+
 
     [SerializeField] private List<PortConnection> connections = new List<PortConnection>();
-    [SerializeField] private string asdf;
-    [SerializeField] private string _id;
+    [SerializeField] private string _fieldName;
     [SerializeField] public Type type;
-    [SerializeField] private string _name;
     [SerializeField] private bool _enabled = true;
     [SerializeField] private IO _direction;
 
-    public NodePort(string name, Type type, Node node, IO direction) {
-        _name = name;
-        this.type = type;
+    public NodePort(FieldInfo fieldInfo, Node node) {
+        _fieldName = fieldInfo.Name;
+        name = _fieldName;
+        type = fieldInfo.FieldType;
         this.node = node;
-        _direction = direction;
-        _id = node.GetInstanceID() + _name;
+
+        var attribs = fieldInfo.GetCustomAttributes(false);
+        for (int i = 0; i < attribs.Length; i++) {
+            if (attribs[i] is Node.InputAttribute) _direction = IO.Input;
+            else if (attribs[i] is Node.InputAttribute) _direction = IO.Output;
+        }
+    }
+
+    /// <summary> Checks all connections for invalid references, and removes them. </summary>
+    public void VerifyConnections() {
+        for (int i = 0; i < connections.Count; i++) {
+            if (connections[i].node != null &&
+                !string.IsNullOrEmpty(connections[i].fieldName) &&
+                connections[i].node.GetPortByFieldName(connections[i].fieldName) != null)
+                continue;
+            Debug.LogWarning("Removed invalid connection");
+            connections.RemoveAt(i);
+        }
     }
 
     /// <summary> Connect this <see cref="NodePort"/> to another </summary>
@@ -86,22 +103,22 @@ public class NodePort {
     [Serializable]
     public class PortConnection {
         [SerializeField] public Node node;
-        [SerializeField] public string portID;
+        [SerializeField] public string fieldName;
         public NodePort Port { get { return port != null ? port : port = GetPort(); } }
         [NonSerialized] private NodePort port;
 
         public PortConnection(NodePort port) {
             this.port = port;
             node = port.node;
-            portID = port.id;
+            fieldName = port.fieldName;
         }
 
         private NodePort GetPort() {
             for (int i = 0; i < node.OutputCount; i++) {
-                if (node.outputs[i].id == portID) return node.outputs[i];
+                if (node.outputs[i].fieldName == fieldName) return node.outputs[i];
             }
             for (int i = 0; i < node.InputCount; i++) {
-                if (node.inputs[i].id == portID) return node.inputs[i];
+                if (node.inputs[i].fieldName == fieldName) return node.inputs[i];
             }
             return null;
         }