diff --git a/src/modules/Elsa.JavaScript/Builders/TypeDefinitionBuilder.cs b/src/modules/Elsa.JavaScript/Builders/TypeDefinitionBuilder.cs
index 2eb6b48f9..182c394d3 100644
--- a/src/modules/Elsa.JavaScript/Builders/TypeDefinitionBuilder.cs
+++ b/src/modules/Elsa.JavaScript/Builders/TypeDefinitionBuilder.cs
@@ -8,7 +8,24 @@ namespace Elsa.JavaScript.Builders;
 public class TypeDefinitionBuilder
 {
     private readonly TypeDefinition _typeDefinition = new();
+    
+    /// <summary>
+    /// Set the name of the function.
+    /// </summary>
+    public TypeDefinitionBuilder Name(string name)
+    {
+        _typeDefinition.Name = name;
+        return this;
+    }
 
+    /// <summary>
+    /// Set the return type of the function.
+    /// </summary>
+    public TypeDefinitionBuilder DeclarationKeyword(string keyword)
+    {
+        _typeDefinition.DeclarationKeyword = keyword;
+        return this;
+    }
 
     /// <summary>
     /// Build a <see cref="TypeDefinition"/> using the collected information.
diff --git a/src/modules/Elsa.JavaScript/Features/JavaScriptFeature.cs b/src/modules/Elsa.JavaScript/Features/JavaScriptFeature.cs
index f0aa0b4e8..a67922726 100644
--- a/src/modules/Elsa.JavaScript/Features/JavaScriptFeature.cs
+++ b/src/modules/Elsa.JavaScript/Features/JavaScriptFeature.cs
@@ -43,8 +43,10 @@ public class JavaScriptFeature : FeatureBase
             .AddSingleton<ITypeDescriber, TypeDescriber>()
             .AddSingleton<ITypeDefinitionDocumentRenderer, TypeDefinitionDocumentRenderer>()
             .AddSingleton<ITypeAliasRegistry, TypeAliasRegistry>()
-            .AddSingleton<IFunctionDefinitionProvider, CommonFunctionDefinitionProvider>()
-            .AddSingleton<ITypeDefinitionProvider, VariableTypeDefinitionProvider>();
+            .AddSingleton<IFunctionDefinitionProvider, CommonFunctionsDefinitionProvider>()
+            .AddSingleton<ITypeDefinitionProvider, CommonTypeDefinitionProvider>()
+            .AddSingleton<ITypeDefinitionProvider, VariableTypeDefinitionProvider>()
+            ;
 
         Module.UseWorkflowManagement(management => management.AddActivitiesFrom<JavaScriptFeature>());
     }
diff --git a/src/modules/Elsa.JavaScript/Implementations/TypeAliasRegistry.cs b/src/modules/Elsa.JavaScript/Implementations/TypeAliasRegistry.cs
index e04a2b1b5..ecc0e5ee3 100644
--- a/src/modules/Elsa.JavaScript/Implementations/TypeAliasRegistry.cs
+++ b/src/modules/Elsa.JavaScript/Implementations/TypeAliasRegistry.cs
@@ -1,5 +1,8 @@
+using System.Dynamic;
 using Elsa.JavaScript.Extensions;
 using Elsa.JavaScript.Services;
+using Elsa.Workflows.Management.Options;
+using Microsoft.Extensions.Options;
 
 namespace Elsa.JavaScript.Implementations;
 
@@ -11,9 +14,10 @@ public class TypeAliasRegistry : ITypeAliasRegistry
     /// <summary>
     /// Constructor.
     /// </summary>
-    public TypeAliasRegistry()
+    public TypeAliasRegistry(IOptions<ManagementOptions> managementOptions)
     {
         this.RegisterType<object>("any");
+        this.RegisterType<ExpandoObject>("any");
         this.RegisterType<string>("string");
         this.RegisterType<bool>("boolean");
         this.RegisterType<short>("number");
@@ -26,6 +30,12 @@ public class TypeAliasRegistry : ITypeAliasRegistry
         this.RegisterType<DateTimeOffset>("Date");
         this.RegisterType<DateOnly>("Date");
         this.RegisterType<TimeOnly>("Date");
+
+        foreach (var variableDescriptor in managementOptions.Value.VariableDescriptors)
+        {
+            if(!_typeAliasDictionary.ContainsKey(variableDescriptor.Type))
+                RegisterType(variableDescriptor.Type, variableDescriptor.Type.Name);
+        }
     }
 
     /// <inheritdoc />
diff --git a/src/modules/Elsa.JavaScript/Implementations/TypeDefinitionDocumentRenderer.cs b/src/modules/Elsa.JavaScript/Implementations/TypeDefinitionDocumentRenderer.cs
index 5900eb851..58f7ad59f 100644
--- a/src/modules/Elsa.JavaScript/Implementations/TypeDefinitionDocumentRenderer.cs
+++ b/src/modules/Elsa.JavaScript/Implementations/TypeDefinitionDocumentRenderer.cs
@@ -27,7 +27,7 @@ public class TypeDefinitionDocumentRenderer : ITypeDefinitionDocumentRenderer
         string RenderParameters(IEnumerable<ParameterDefinition> parameters) => string.Join(", ", parameters.Select(RenderParameter));
         
         var returnType = functionDefinition.ReturnType != null ? $": {functionDefinition.ReturnType}" : "";
-        output.AppendLine($"declare function {functionDefinition.Name}({RenderParameters(functionDefinition.Parameters)}){returnType}");
+        output.AppendLine($"declare function {functionDefinition.Name}({RenderParameters(functionDefinition.Parameters)}){returnType};");
     }
 
     private void Render(TypeDefinition typeDefinition, StringBuilder output)
@@ -40,5 +40,5 @@ public class TypeDefinitionDocumentRenderer : ITypeDefinitionDocumentRenderer
         output.AppendLine("}");
     }
 
-    private void Render(PropertyDefinition property, StringBuilder output) => output.AppendLine($"{property.Name}{(property.IsOptional ? "?" : "")}: {property.Type}");
+    private void Render(PropertyDefinition property, StringBuilder output) => output.AppendLine($"{property.Name}{(property.IsOptional ? "?" : "")}: {property.Type};");
 }
\ No newline at end of file
diff --git a/src/modules/Elsa.JavaScript/Providers/CommonTypesDefinitionProvider.cs b/src/modules/Elsa.JavaScript/Providers/CommonTypesDefinitionProvider.cs
new file mode 100644
index 000000000..4b7810d45
--- /dev/null
+++ b/src/modules/Elsa.JavaScript/Providers/CommonTypesDefinitionProvider.cs
@@ -0,0 +1,25 @@
+using System.Text.Json.Nodes;
+using Elsa.JavaScript.Abstractions;
+using Elsa.JavaScript.Models;
+using Elsa.JavaScript.Services;
+
+namespace Elsa.JavaScript.Providers;
+
+/// <summary>
+/// Produces <see cref="FunctionDefinition"/>s for common functions.
+/// </summary>
+internal class CommonTypeDefinitionProvider : TypeDefinitionProvider
+{
+    private readonly ITypeDescriber _typeDescriber;
+
+    public CommonTypeDefinitionProvider(ITypeDescriber typeDescriber)
+    {
+        _typeDescriber = typeDescriber;
+    }
+
+    protected override IEnumerable<TypeDefinition> GetTypeDefinitions(TypeDefinitionContext context)
+    {
+        yield return _typeDescriber.DescribeType(typeof(Guid));
+        yield return _typeDescriber.DescribeType(typeof(JsonObject));
+    }
+}
\ No newline at end of file
diff --git a/src/modules/Elsa.Workflows.Management/Implementations/IActivityPropertyOptionsProvider.cs b/src/modules/Elsa.Workflows.Management/Implementations/IActivityPropertyOptionsProvider.cs
index 543187335..ee76f42ef 100644
--- a/src/modules/Elsa.Workflows.Management/Implementations/IActivityPropertyOptionsProvider.cs
+++ b/src/modules/Elsa.Workflows.Management/Implementations/IActivityPropertyOptionsProvider.cs
@@ -10,5 +10,5 @@ public interface IActivityPropertyOptionsProvider
     /// <summary>
     /// Returns options for the specified property.
     /// </summary>
-    object GetOptions(PropertyInfo property);
+    object? GetOptions(PropertyInfo property);
 }
\ No newline at end of file