Fixed two issues, and added two new features.

src/ClassGraph/ClassGraph.cs

@@ -1,4 +1,4 @@
-namespace DiagramGenerator.ClassGraph;
+namespace ClassGraph;
 
 public class Graph
 {

src/ClassGraph/DiagramDirection.cs

@@ -0,0 +1,9 @@
+namespace ClassGraph;
+
+public enum DiagramDirection
+{
+    TB, // Top to Bottom
+    BT, // Bottom to Top
+    LR, // Left to Right
+    RL  // Right to Left
+}

src/ClassGraph/IDiagramGenerator.cs

@@ -1,6 +1,6 @@
-namespace DiagramGenerator.ClassGraph;
+namespace ClassGraph;
 
 public interface IDiagramGenerator
 {
-    string Generate(Graph graph);
+    string Generate(Graph graph, bool highLevelOnly, DiagramDirection diagramDirection);
 }

src/ClassGraph/IGraphBuilder.cs

@@ -1,4 +1,4 @@
-namespace DiagramGenerator.ClassGraph;
+namespace ClassGraph;
 
 public interface IGraphBuilder
 {

src/ClassGraph/MermaidGenerator.cs

@@ -1,9 +1,10 @@
-namespace DiagramGenerator.ClassGraph;
+namespace ClassGraph;
 
 public class MermaidGenerator : IDiagramGenerator {
   private static string MDFrame =
       @"```mermaid
 classDiagram
+    direction {2}
 
 {0}
 {1}
@@ -15,16 +16,23 @@ public class MermaidGenerator : IDiagramGenerator {
 {1}{2}
 }}";
 
-  public string Generate(Graph graph) {
+  public string Generate(Graph graph, bool highLevelOnly, DiagramDirection diagramDirection) {
     var allClass = new List<string>();
     foreach (var @class in graph.Classes) {
-      var classString = GenerateClass(@class);
+            // fixed an issue where a class with empty name would generate invalid
+            // Mermaid syntax and break the entire diagram - just skip any classes with empty/whitespace names
+            if (string.IsNullOrWhiteSpace(@class.Name)) continue;
+      var classString = GenerateClass(@class, highLevelOnly);
       allClass.Add(classString);
     }
 
     var allRelation = new List<string>();
     foreach (var relation in graph.Relations) {
-      var relationString = GenerateRelation(relation);
+            // if either end of the relation has empty/whitespace name, skip it to avoid breaking Mermaid syntax
+            if (string.IsNullOrWhiteSpace(relation.From?.Name) ||
+            string.IsNullOrWhiteSpace(relation.To?.Name)) continue;
+
+        var relationString = GenerateRelation(relation);
       allRelation.Add(relationString);
     }
 
@@ -40,10 +48,10 @@ public string Generate(Graph graph) {
       sections += "\r\n\r\n" + relationSection;
     }
 
-    return string.Format(MDFrame, sections, string.Empty);
+    return string.Format(MDFrame, sections, string.Empty, diagramDirection.ToString());
   }
 
-  private string GenerateClass(Class @class) {
+  private string GenerateClass(Class @class, bool highLevelOnly) {
     var lines = new List<string>();
 
     // Add type annotation (<<interface>>, <<record>>, etc.) as first line inside class block
@@ -52,6 +60,10 @@ private string GenerateClass(Class @class) {
       lines.Add($"  {typeAnnotation}");
     }
 
+    if (highLevelOnly) {
+      return string.Format(ClassFrame, @class.Name, string.Empty, string.Empty);
+    }
+
     // For enums, add enum values instead of properties/methods
     if (@class.Kind == TypeKind.Enum) {
       foreach (var enumValue in @class.EnumValues) {

src/ClassGraph/SourceGraphBuilder.cs

@@ -2,7 +2,7 @@
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 
-namespace DiagramGenerator.ClassGraph;
+namespace ClassGraph;
 
 public class SourceGraphBuilder : IGraphBuilder
 {

src/MermaidClassDiagramGenerator/Program.cs

@@ -1,5 +1,5 @@
 using System.CommandLine;
-using DiagramGenerator.ClassGraph;
+using ClassGraph;
 
 var outputOption = new Option<FileInfo?>(
     aliases: new[] { "--output", "-o" },
@@ -20,7 +20,8 @@
 var tnOption = new Option<IList<string>>(
     aliases: new[] { "--type-names", "-t" },
     description: "Specific classes to include.",
-    getDefaultValue: () => new List<string>());
+    getDefaultValue: () => new List<string>())
+    { AllowMultipleArgumentsPerToken = true };
 
 var ignoreDependencyOption = new Option<bool>(
     name: "--ignore-dependency",
@@ -44,6 +45,16 @@
     description: "Additional patterns to exclude from file search (e.g., 'Migrations', 'Generated').",
     getDefaultValue: () => new List<string>());
 
+var highLevelOnlyOption = new Option<bool>(
+        aliases: new[] { "--high-level-only" },
+        description: "Exclude all properties, methods, etc from generated diagram.",
+        getDefaultValue: () => false);
+
+var diagramDirectionOption = new Option<DiagramDirection>(
+    aliases: new[] { "--diagram-direction", "-d" },
+    description: "The direction that diagram should be generated (TB: Top to Bottom (default), BT: Bottom to Top, LR: Left to Right, RL: Right to Left)",
+    getDefaultValue: () => DiagramDirection.TB);
+
 var rootCommand = new RootCommand("Generate mermaid.js class-diagram from C# source code files.");
 rootCommand.AddOption(outputOption);
 rootCommand.AddOption(nsOption);
@@ -54,6 +65,8 @@
 rootCommand.AddOption(visibilityOption);
 rootCommand.AddOption(verboseOption);
 rootCommand.AddOption(excludePatternsOption);
+rootCommand.AddOption(highLevelOnlyOption);
+rootCommand.AddOption(diagramDirectionOption);
 
 rootCommand.SetHandler((context) =>
 {
@@ -66,8 +79,10 @@
     var visLevel = context.ParseResult.GetValueForOption(visibilityOption);
     var verbose = context.ParseResult.GetValueForOption(verboseOption);
     var excludePatterns = context.ParseResult.GetValueForOption(excludePatternsOption);
+    var highLevelOnly = context.ParseResult.GetValueForOption(highLevelOnlyOption);
+    var diagramDirection = context.ParseResult.GetValueForOption(diagramDirectionOption);
 
-    Execute(output!, ns!, inputPath!, tns!, ignoreDep, excludeSys, visLevel!, verbose, excludePatterns!);
+    Execute(output!, ns!, inputPath!, tns!, ignoreDep, excludeSys, visLevel!, verbose, excludePatterns!, highLevelOnly, diagramDirection);
 });
 
 return await rootCommand.InvokeAsync(args);
@@ -80,7 +95,9 @@ static void Execute(FileInfo outputFile,
     bool excludeSystemTypes,
     string visibilityLevel,
     bool verbose,
-    IList<string> excludePatterns)
+    IList<string> excludePatterns,
+    bool highLevelOnly,
+    DiagramDirection diagramDirection)
 {
     try
     {
@@ -142,7 +159,7 @@ static void Execute(FileInfo outputFile,
 
         // 3. Generate Mermaid diagram
         var generator = new MermaidGenerator();
-        var text = generator.Generate(graph);
+        var text = generator.Generate(graph, highLevelOnly, diagramDirection);
 
         // 4. Write output
         File.WriteAllText(outputFile.FullName, text);

src/MermaidClassDiagramGenerator/Properties/launchSettings.json

@@ -0,0 +1,7 @@
+{
+  "profiles": {
+    "MermaidClassDiagramGenerator": {
+      "commandName": "Project"
+    }
+  }
+}