diff --git a/StabilityMatrix.Core/Attributes/TypedNodeOptionsAttribute.cs b/StabilityMatrix.Core/Attributes/TypedNodeOptionsAttribute.cs
index f496abc4..44d019fd 100644
--- a/StabilityMatrix.Core/Attributes/TypedNodeOptionsAttribute.cs
+++ b/StabilityMatrix.Core/Attributes/TypedNodeOptionsAttribute.cs
@@ -1,4 +1,5 @@
 using StabilityMatrix.Core.Models.Api.Comfy.Nodes;
+using StabilityMatrix.Core.Models.Packages.Extensions;
 
 namespace StabilityMatrix.Core.Attributes;
 
@@ -11,4 +12,9 @@ public class TypedNodeOptionsAttribute : Attribute
     public string? Name { get; init; }
 
     public string[]? RequiredExtensions { get; init; }
+
+    public IEnumerable<ExtensionSpecifier> GetRequiredExtensionSpecifiers()
+    {
+        return RequiredExtensions?.Select(ExtensionSpecifier.Parse) ?? Enumerable.Empty<ExtensionSpecifier>();
+    }
 }
diff --git a/StabilityMatrix.Core/Models/Api/Comfy/Nodes/NodeDictionary.cs b/StabilityMatrix.Core/Models/Api/Comfy/Nodes/NodeDictionary.cs
index 5fbe4464..da088767 100644
--- a/StabilityMatrix.Core/Models/Api/Comfy/Nodes/NodeDictionary.cs
+++ b/StabilityMatrix.Core/Models/Api/Comfy/Nodes/NodeDictionary.cs
@@ -1,10 +1,12 @@
 using System.ComponentModel;
 using System.Reflection;
 using System.Text.Json.Serialization;
+using KGySoft.CoreLibraries;
 using OneOf;
 using StabilityMatrix.Core.Attributes;
 using StabilityMatrix.Core.Helper;
 using StabilityMatrix.Core.Models.Api.Comfy.NodeTypes;
+using StabilityMatrix.Core.Models.Packages.Extensions;
 
 namespace StabilityMatrix.Core.Models.Api.Comfy.Nodes;
 
@@ -19,7 +21,10 @@ public class NodeDictionary : Dictionary<string, ComfyNode>
     /// When inserting TypedNodes, this holds a mapping of ClassType to required extensions
     /// </summary>
     [JsonIgnore]
-    public Dictionary<string, string[]> ClassTypeRequiredExtensions { get; } = new();
+    public Dictionary<string, ExtensionSpecifier[]> ClassTypeRequiredExtensions { get; } = new();
+
+    public IEnumerable<ExtensionSpecifier> RequiredExtensions =>
+        ClassTypeRequiredExtensions.Values.SelectMany(x => x);
 
     /// <summary>
     /// Finds a unique node name given a base name, by appending _2, _3, etc.
@@ -63,7 +68,11 @@ public class NodeDictionary : Dictionary<string, ComfyNode>
         {
             if (options.RequiredExtensions != null)
             {
-                ClassTypeRequiredExtensions[namedNode.ClassType] = options.RequiredExtensions;
+                ClassTypeRequiredExtensions.AddOrUpdate(
+                    namedNode.ClassType,
+                    _ => options.GetRequiredExtensionSpecifiers().ToArray(),
+                    (_, specifiers) => options.GetRequiredExtensionSpecifiers().Concat(specifiers).ToArray()
+                );
             }
         }
 
diff --git a/StabilityMatrix.Core/Models/Packages/Extensions/ExtensionSpecifier.cs b/StabilityMatrix.Core/Models/Packages/Extensions/ExtensionSpecifier.cs
new file mode 100644
index 00000000..13003ca0
--- /dev/null
+++ b/StabilityMatrix.Core/Models/Packages/Extensions/ExtensionSpecifier.cs
@@ -0,0 +1,105 @@
+using System.Diagnostics.CodeAnalysis;
+using System.Text.RegularExpressions;
+using JetBrains.Annotations;
+using Semver;
+using StabilityMatrix.Core.Processes;
+
+namespace StabilityMatrix.Core.Models.Packages.Extensions;
+
+/// <summary>
+/// Extension specifier with optional version constraints.
+/// </summary>
+[PublicAPI]
+public partial class ExtensionSpecifier
+{
+    public required string Name { get; init; }
+
+    public string? Constraint { get; init; }
+
+    public string? Version { get; init; }
+
+    public string? VersionConstraint => Constraint is null || Version is null ? null : Constraint + Version;
+
+    public bool TryGetSemVersionRange([NotNullWhen(true)] out SemVersionRange? semVersionRange)
+    {
+        if (!string.IsNullOrEmpty(VersionConstraint))
+        {
+            return SemVersionRange.TryParse(
+                VersionConstraint,
+                SemVersionRangeOptions.Loose,
+                out semVersionRange
+            );
+        }
+
+        semVersionRange = null;
+        return false;
+    }
+
+    public static ExtensionSpecifier Parse(string value)
+    {
+        TryParse(value, true, out var packageSpecifier);
+
+        return packageSpecifier!;
+    }
+
+    public static bool TryParse(string value, [NotNullWhen(true)] out ExtensionSpecifier? extensionSpecifier)
+    {
+        return TryParse(value, false, out extensionSpecifier);
+    }
+
+    private static bool TryParse(
+        string value,
+        bool throwOnFailure,
+        [NotNullWhen(true)] out ExtensionSpecifier? packageSpecifier
+    )
+    {
+        var match = ExtensionSpecifierRegex().Match(value);
+        if (!match.Success)
+        {
+            if (throwOnFailure)
+            {
+                throw new ArgumentException($"Invalid extension specifier: {value}");
+            }
+
+            packageSpecifier = null;
+            return false;
+        }
+
+        packageSpecifier = new ExtensionSpecifier
+        {
+            Name = match.Groups["extension_name"].Value,
+            Constraint = match.Groups["version_constraint"].Value,
+            Version = match.Groups["version"].Value
+        };
+
+        return true;
+    }
+
+    /// <inheritdoc />
+    public override string ToString()
+    {
+        return Name + VersionConstraint;
+    }
+
+    public static implicit operator Argument(ExtensionSpecifier specifier)
+    {
+        return specifier.VersionConstraint is null
+            ? new Argument(specifier.Name)
+            : new Argument((specifier.Name, specifier.VersionConstraint));
+    }
+
+    public static implicit operator ExtensionSpecifier(string specifier)
+    {
+        return Parse(specifier);
+    }
+
+    /// <summary>
+    /// Regex to match a pip package specifier.
+    /// </summary>
+    [GeneratedRegex(
+        @"(?<extension_name>\S+)\s*(?<version_constraint>==|>=|<=|>|<|~=|!=)?\s*(?<version>[a-zA-Z0-9_.]+)?",
+        RegexOptions.CultureInvariant,
+        5000
+    )]
+    private static partial Regex ExtensionSpecifierRegex();
+}