diff --git a/README.md b/README.md
index 54d8978..b0d5a7d 100644
--- a/README.md
+++ b/README.md
@@ -37,13 +37,15 @@ Usage: spdx-tool [options] <command> [arguments]
 Options:
   -h, --help                               Show this help message and exit
   -v, --version                            Show version information and exit
+  -l, --log <log-file>                     Log output to file
+  -s, --silent                             Silence console output
 
 Commands:
   help <command>                           Display extended help about a command
   add-package                              Add package to SPDX document (workflow only).
   add-relationship <spdx.json> <args>      Add relationship between elements.
   copy-package <spdx.json> <args>          Copy package between SPDX documents (workflow only).
-  diagram <spdx.json> <mermaid.txt>        Generate mermaid diagram.
+  diagram <spdx.json> <mermaid.txt> [tools] Generate mermaid diagram.
   find-package <spdx.json> <criteria>      Find package ID in SPDX document
   get-version <spdx.json> <criteria>       Get the version of an SPDX package.
   hash <operation> <algorithm> <file>      Generate or verify hashes of files
diff --git a/src/DemaConsulting.SpdxTool/Commands/AddPackage.cs b/src/DemaConsulting.SpdxTool/Commands/AddPackage.cs
index 7de3c88..177604a 100644
--- a/src/DemaConsulting.SpdxTool/Commands/AddPackage.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/AddPackage.cs
@@ -92,13 +92,13 @@ private AddPackage()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         throw new CommandUsageException("'add-package' command is only valid in a workflow");
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
diff --git a/src/DemaConsulting.SpdxTool/Commands/AddRelationship.cs b/src/DemaConsulting.SpdxTool/Commands/AddRelationship.cs
index 9ac70e7..eb528b6 100644
--- a/src/DemaConsulting.SpdxTool/Commands/AddRelationship.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/AddRelationship.cs
@@ -82,7 +82,7 @@ private AddRelationship()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         // Report an error if the number of arguments is less than 4
         if (args.Length < 4)
@@ -102,7 +102,7 @@ public override void Run(string[] args)
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
diff --git a/src/DemaConsulting.SpdxTool/Commands/Command.cs b/src/DemaConsulting.SpdxTool/Commands/Command.cs
index 9419cfb..6fae50d 100644
--- a/src/DemaConsulting.SpdxTool/Commands/Command.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/Command.cs
@@ -30,15 +30,17 @@ public abstract class Command
     /// <summary>
     /// Run the command
     /// </summary>
+    /// <param name="context">Program context</param>
     /// <param name="args">Command arguments</param>
-    public abstract void Run(string[] args);
+    public abstract void Run(Context context, string[] args);
 
     /// <summary>
     /// Run the command
     /// </summary>
+    /// <param name="context">Program context</param>
     /// <param name="step">Command step</param>
     /// <param name="variables">Workflow variables</param>
-    public abstract void Run(YamlMappingNode step, Dictionary<string, string> variables);
+    public abstract void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables);
 
     /// <summary>
     /// Expand variables in text
diff --git a/src/DemaConsulting.SpdxTool/Commands/CopyPackage.cs b/src/DemaConsulting.SpdxTool/Commands/CopyPackage.cs
index d424d54..3715bf5 100644
--- a/src/DemaConsulting.SpdxTool/Commands/CopyPackage.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/CopyPackage.cs
@@ -86,7 +86,7 @@ private CopyPackage()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         // Report an error if the number of arguments is less than 3
         if (args.Length < 3)
@@ -122,7 +122,7 @@ public override void Run(string[] args)
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
diff --git a/src/DemaConsulting.SpdxTool/Commands/Diagram.cs b/src/DemaConsulting.SpdxTool/Commands/Diagram.cs
index b707683..65832df 100644
--- a/src/DemaConsulting.SpdxTool/Commands/Diagram.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/Diagram.cs
@@ -88,7 +88,7 @@ private Diagram()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         // Report an error if the number of arguments is less than 2
         if (args.Length < 2)
@@ -110,7 +110,7 @@ public override void Run(string[] args)
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
diff --git a/src/DemaConsulting.SpdxTool/Commands/FindPackage.cs b/src/DemaConsulting.SpdxTool/Commands/FindPackage.cs
index 870014e..3cb6c19 100644
--- a/src/DemaConsulting.SpdxTool/Commands/FindPackage.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/FindPackage.cs
@@ -82,7 +82,7 @@ private FindPackage()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         // Report an error if insufficient arguments
         if (args.Length < 2)
@@ -97,11 +97,11 @@ public override void Run(string[] args)
         var packageId = FindPackageByCriteria(spdxFile, criteria).Id;
 
         // Write the package ID to the console
-        Console.WriteLine(packageId);
+        context.WriteLine(packageId);
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
diff --git a/src/DemaConsulting.SpdxTool/Commands/GetVersion.cs b/src/DemaConsulting.SpdxTool/Commands/GetVersion.cs
index a8137f5..ce6781f 100644
--- a/src/DemaConsulting.SpdxTool/Commands/GetVersion.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/GetVersion.cs
@@ -79,7 +79,7 @@ private GetVersion()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         // Report an error if insufficient arguments
         if (args.Length < 2)
@@ -94,11 +94,11 @@ public override void Run(string[] args)
         var packageVersion = FindPackage.FindPackageByCriteria(spdxFile, criteria).Version;
 
         // Print the version
-        Console.WriteLine(packageVersion);
+        context.WriteLine(packageVersion ?? "");
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
diff --git a/src/DemaConsulting.SpdxTool/Commands/Hash.cs b/src/DemaConsulting.SpdxTool/Commands/Hash.cs
index fb50389..cdee501 100644
--- a/src/DemaConsulting.SpdxTool/Commands/Hash.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/Hash.cs
@@ -69,7 +69,7 @@ private Hash()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         // Report an error if the number of arguments is not 3
         if (args.Length != 3)
@@ -79,11 +79,11 @@ public override void Run(string[] args)
         var operation = args[0];
         var algorithm = args[1];
         var file = args[2];
-        DoHashOperation(operation, algorithm, file);
+        DoHashOperation(context, operation, algorithm, file);
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
@@ -101,17 +101,18 @@ public override void Run(YamlMappingNode step, Dictionary<string, string> variab
                    throw new YamlException(step.Start, step.End, "'hash' command missing 'file' input");
 
         // Do the hash operation
-        DoHashOperation(operation, algorithm, file);
+        DoHashOperation(context, operation, algorithm, file);
     }
 
     /// <summary>
     /// Do the requested Sha256 operation
     /// </summary>
+    /// <param name="context">Program context</param>
     /// <param name="operation">Operation to perform (generate or verify)</param>
     /// <param name="algorithm">Hash algorithm</param>
     /// <param name="file">File to perform operation on</param>
     /// <exception cref="CommandUsageException">On usage error</exception>
-    public static void DoHashOperation(string operation, string algorithm, string file)
+    public static void DoHashOperation(Context context, string operation, string algorithm, string file)
     {
         // Check the algorithm
         if (algorithm != "sha256")
@@ -125,7 +126,7 @@ public static void DoHashOperation(string operation, string algorithm, string fi
                 break;
 
             case "verify":
-                VerifySha256(file);
+                VerifySha256(context, file);
                 break;
 
             default:
@@ -149,9 +150,10 @@ public static void GenerateSha256(string file)
     /// <summary>
     /// Verify a Sha256 hash for a file
     /// </summary>
-    /// <param name="file"></param>
+    /// <param name="context">Program context</param>
+    /// <param name="file">Name of the file to verify</param>
     /// <exception cref="CommandErrorException"></exception>
-    public static void VerifySha256(string file)
+    public static void VerifySha256(Context context, string file)
     {
         // Check the hash file exists
         var hashFile = file + ".sha256";
@@ -169,7 +171,7 @@ public static void VerifySha256(string file)
             throw new CommandErrorException($"Sha256 hash mismatch for '{file}'");
 
         // Report the digest is OK
-        Console.WriteLine($"Sha256 Digest OK for '{file}'");
+        context.WriteLine($"Sha256 Digest OK for '{file}'");
     }
 
     /// <summary>
diff --git a/src/DemaConsulting.SpdxTool/Commands/Help.cs b/src/DemaConsulting.SpdxTool/Commands/Help.cs
index 1cf4613..7a4e180 100644
--- a/src/DemaConsulting.SpdxTool/Commands/Help.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/Help.cs
@@ -66,18 +66,18 @@ private Help()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         // Report an error if the number of arguments is not 1
         if (args.Length != 1)
             throw new CommandUsageException("'help' command missing arguments");
 
         // Generate the markdown
-        ShowUsage(args[0]);
+        ShowUsage(context, args[0]);
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
@@ -87,15 +87,16 @@ public override void Run(YamlMappingNode step, Dictionary<string, string> variab
                     throw new YamlException(step.Start, step.End, "'help' command missing 'about' input");
 
         // Generate the markdown
-        ShowUsage(about);
+        ShowUsage(context, about);
     }
 
     /// <summary>
     /// Show the usage for the requested command
     /// </summary>
-    /// <param name="command"></param>
+    /// <param name="context">Program context</param>
+    /// <param name="command">Command to get help on</param>
     /// <exception cref="CommandUsageException">On error</exception>
-    public static void ShowUsage(string command)
+    public static void ShowUsage(Context context, string command)
     {
         // Get the entry for the command
         if (!CommandsRegistry.Commands.TryGetValue(command, out var entry))
@@ -103,6 +104,6 @@ public static void ShowUsage(string command)
 
         // Display the command entry
         foreach (var line in entry.Details)
-            Console.WriteLine(line);
+            context.WriteLine(line);
     }
 }
\ No newline at end of file
diff --git a/src/DemaConsulting.SpdxTool/Commands/Print.cs b/src/DemaConsulting.SpdxTool/Commands/Print.cs
index 4b46c70..f233fcf 100644
--- a/src/DemaConsulting.SpdxTool/Commands/Print.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/Print.cs
@@ -68,14 +68,14 @@ private Print()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         foreach (var arg in args)
-            Console.WriteLine(arg);
+            context.WriteLine(arg);
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
@@ -88,7 +88,7 @@ public override void Run(YamlMappingNode step, Dictionary<string, string> variab
         for (var i = 0; i < text.Children.Count; i++)
         {
             var line = GetSequenceString(text, i, variables) ?? string.Empty;
-            Console.WriteLine(line);
+            context.WriteLine(line);
         }
     }
 }
\ No newline at end of file
diff --git a/src/DemaConsulting.SpdxTool/Commands/Query.cs b/src/DemaConsulting.SpdxTool/Commands/Query.cs
index aff1df8..2527d17 100644
--- a/src/DemaConsulting.SpdxTool/Commands/Query.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/Query.cs
@@ -74,7 +74,7 @@ private Query()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         // Report an error if the number of arguments is not 1
         if (args.Length < 2)
@@ -83,12 +83,12 @@ public override void Run(string[] args)
         // Generate the markdown
         var found = QueryProgramOutput(args[0], args[1], args.Skip(2).ToArray());
 
-        // Write the found value to the console
-        Console.WriteLine(found);
+        // Write the found value
+        context.WriteLine(found);
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
diff --git a/src/DemaConsulting.SpdxTool/Commands/RenameId.cs b/src/DemaConsulting.SpdxTool/Commands/RenameId.cs
index f786d57..e50768a 100644
--- a/src/DemaConsulting.SpdxTool/Commands/RenameId.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/RenameId.cs
@@ -70,7 +70,7 @@ private RenameId()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         // Report an error if the number of arguments is not 3
         if (args.Length != 3)
@@ -81,7 +81,7 @@ public override void Run(string[] args)
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
diff --git a/src/DemaConsulting.SpdxTool/Commands/RunWorkflow.cs b/src/DemaConsulting.SpdxTool/Commands/RunWorkflow.cs
index 1243a76..493bb7b 100644
--- a/src/DemaConsulting.SpdxTool/Commands/RunWorkflow.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/RunWorkflow.cs
@@ -75,7 +75,7 @@ private RunWorkflow()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         // Report an error if the number of arguments is less than 1
         if (args.Length < 1)
@@ -107,20 +107,20 @@ public override void Run(string[] args)
         }
 
         // Execute the workflow
-        var outputs = name.StartsWith("http") ? RunUrl(name, null, parameters) : RunFile(name, null, parameters);
+        var outputs = name.StartsWith("http") ? RunUrl(context, name, null, parameters) : RunFile(context, name, null, parameters);
 
         // Skip if not verbose
         if (!verbose)
             return;
 
         // Print the outputs
-        Console.WriteLine("Outputs:");
+        context.WriteLine("Outputs:");
         foreach (var (key, value) in outputs)
-            Console.WriteLine($"  {key} = {value}");
+            context.WriteLine($"  {key} = {value}");
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
@@ -144,7 +144,7 @@ public override void Run(YamlMappingNode step, Dictionary<string, string> variab
             }
 
         // Run the workflow
-        var outputs = Run(step, file, url, integrity, parameters);
+        var outputs = Run(context, step, file, url, integrity, parameters);
         
         // Save any outputs
         if (GetMapMap(inputs, "outputs") is { } outputsMap)
@@ -163,6 +163,7 @@ public override void Run(YamlMappingNode step, Dictionary<string, string> variab
     /// <summary>
     /// Execute the workflow
     /// </summary>
+    /// <param name="context">Program context</param>
     /// <param name="step">Step for reporting errors</param>
     /// <param name="file">Optional file</param>
     /// <param name="url">Optional URL</param>
@@ -170,7 +171,7 @@ public override void Run(YamlMappingNode step, Dictionary<string, string> variab
     /// <param name="parameters">Workflow parameters</param>
     /// <returns>Workflow outputs</returns>
     /// <exception cref="YamlException">on error</exception>
-    public static Dictionary<string, string> Run(YamlMappingNode step, string? file, string? url, string? integrity, Dictionary<string, string> parameters)
+    public static Dictionary<string, string> Run(Context context, YamlMappingNode step, string? file, string? url, string? integrity, Dictionary<string, string> parameters)
     {
         // Fail if no source
         if (file != null && url != null)
@@ -178,11 +179,11 @@ public static Dictionary<string, string> Run(YamlMappingNode step, string? file,
 
         // Run the file if specified
         if (file != null)
-            return RunFile(file, integrity, parameters);
+            return RunFile(context, file, integrity, parameters);
 
         // Run the URL if specified
         if (url != null)
-            return RunUrl(url, integrity, parameters);
+            return RunUrl(context, url, integrity, parameters);
 
         // No source provided
         throw new YamlException(step.Start, step.End, "'run-workflow' command must specify either 'file' or 'url' input");
@@ -191,13 +192,14 @@ public static Dictionary<string, string> Run(YamlMappingNode step, string? file,
     /// <summary>
     /// Execute the workflow
     /// </summary>
+    /// <param name="context">Program context</param>
     /// <param name="workflowFile">Workflow file</param>
     /// <param name="integrity">Optional integrity hash</param>
     /// <param name="parameters">Workflow parameters</param>
     /// <returns>Workflow outputs</returns>
     /// <exception cref="CommandUsageException">On usage error</exception>
     /// <exception cref="YamlException">On workflow error</exception>
-    public static Dictionary<string, string> RunFile(string workflowFile, string? integrity, Dictionary<string, string> parameters)
+    public static Dictionary<string, string> RunFile(Context context, string workflowFile, string? integrity, Dictionary<string, string> parameters)
     {
         // Verify the file exists
         if (!File.Exists(workflowFile))
@@ -208,18 +210,19 @@ public static Dictionary<string, string> RunFile(string workflowFile, string? in
         var bytes = File.ReadAllBytes(workflowFile);
 
         // Run the workflow
-        return RunBytes(workflowFile, bytes, integrity, parameters);
+        return RunBytes(context, workflowFile, bytes, integrity, parameters);
     }
 
     /// <summary>
     /// Run workflow from URL
     /// </summary>
+    /// <param name="context">Program context</param>
     /// <param name="url">Workflow URL</param>
     /// <param name="integrity">Optional integrity hash</param>
     /// <param name="parameters">Workflow parameters</param>
     /// <returns>Workflow outputs</returns>
     /// <exception cref="CommandErrorException">on error</exception>
-    public static Dictionary<string, string> RunUrl(string url, string? integrity, Dictionary<string, string> parameters)
+    public static Dictionary<string, string> RunUrl(Context context, string url, string? integrity, Dictionary<string, string> parameters)
     {
         // Construct the client handler to use the system proxy
         var handler = new HttpClientHandler
@@ -245,18 +248,19 @@ public static Dictionary<string, string> RunUrl(string url, string? integrity, D
         var bytes = bytesTask.Result;
 
         // Run the workflow
-        return RunBytes(url, bytes, integrity, parameters);
+        return RunBytes(context, url, bytes, integrity, parameters);
     }
 
     /// <summary>
     /// Execute the workflow from Yaml bytes (from file, url, etc.)
     /// </summary>
+    /// <param name="context">Program context</param>
     /// <param name="source">Yaml source</param>
     /// <param name="bytes">Yaml bytes</param>
     /// <param name="integrity">Optional integrity hash</param>
     /// <param name="parameters">Parameters</param>
     /// <returns>Workflow outputs</returns>
-    public static Dictionary<string, string> RunBytes(string source, byte[] bytes, string? integrity, Dictionary<string, string> parameters)
+    public static Dictionary<string, string> RunBytes(Context context, string source, byte[] bytes, string? integrity, Dictionary<string, string> parameters)
     {
         // Optionally check the integrity before running
         if (integrity != null)
@@ -319,7 +323,7 @@ public static Dictionary<string, string> RunBytes(string source, byte[] bytes, s
                 // Check for a displayName
                 var displayName = GetMapString(step, "displayName", variables);
                 if (displayName != null)
-                    Console.WriteLine(displayName);
+                    context.WriteLine(displayName);
 
                 // Execute the step
                 if (!CommandsRegistry.Commands.TryGetValue(command, out var entry))
@@ -327,7 +331,7 @@ public static Dictionary<string, string> RunBytes(string source, byte[] bytes, s
                         $"Unknown command: '{command}'");
 
                 // Run the command
-                entry.Instance.Run(step, variables);
+                entry.Instance.Run(context, step, variables);
             }
 
             // Return our variables as the output
diff --git a/src/DemaConsulting.SpdxTool/Commands/SetVariable.cs b/src/DemaConsulting.SpdxTool/Commands/SetVariable.cs
index a54e077..b8e11c7 100644
--- a/src/DemaConsulting.SpdxTool/Commands/SetVariable.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/SetVariable.cs
@@ -63,13 +63,13 @@ private SetVariable()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         throw new CommandUsageException("'set-variable' command is only valid in a workflow");
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
diff --git a/src/DemaConsulting.SpdxTool/Commands/ToMarkdown.cs b/src/DemaConsulting.SpdxTool/Commands/ToMarkdown.cs
index 04ff285..d3d8c6d 100644
--- a/src/DemaConsulting.SpdxTool/Commands/ToMarkdown.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/ToMarkdown.cs
@@ -72,7 +72,7 @@ private ToMarkdown()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         // Report an error if the number of arguments is less than 2
         if (args.Length < 2)
@@ -97,7 +97,7 @@ public override void Run(string[] args)
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
diff --git a/src/DemaConsulting.SpdxTool/Commands/UpdatePackage.cs b/src/DemaConsulting.SpdxTool/Commands/UpdatePackage.cs
index a8e22e3..8a95e55 100644
--- a/src/DemaConsulting.SpdxTool/Commands/UpdatePackage.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/UpdatePackage.cs
@@ -76,13 +76,13 @@ private UpdatePackage()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         throw new CommandUsageException("'update-package' command is only valid in a workflow");
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
diff --git a/src/DemaConsulting.SpdxTool/Commands/Validate.cs b/src/DemaConsulting.SpdxTool/Commands/Validate.cs
index 0b65514..d44318c 100644
--- a/src/DemaConsulting.SpdxTool/Commands/Validate.cs
+++ b/src/DemaConsulting.SpdxTool/Commands/Validate.cs
@@ -68,7 +68,7 @@ private Validate()
     }
 
     /// <inheritdoc />
-    public override void Run(string[] args)
+    public override void Run(Context context, string[] args)
     {
         // Report an error if for missing arguments
         if (args.Length == 0)
@@ -79,11 +79,11 @@ public override void Run(string[] args)
         var ntia = args.Skip(1).Any(a => a == "ntia");
         
         // Perform validation
-        DoValidate(spdxFile, ntia);
+        DoValidate(context, spdxFile, ntia);
     }
 
     /// <inheritdoc />
-    public override void Run(YamlMappingNode step, Dictionary<string, string> variables)
+    public override void Run(Context context, YamlMappingNode step, Dictionary<string, string> variables)
     {
         // Get the step inputs
         var inputs = GetMapMap(step, "inputs");
@@ -97,16 +97,17 @@ public override void Run(YamlMappingNode step, Dictionary<string, string> variab
         var ntia = ntiaValue?.ToLowerInvariant() == "true";
 
         // Perform validation
-        DoValidate(spdxFile, ntia);
+        DoValidate(context, spdxFile, ntia);
     }
 
     /// <summary>
     /// Validate SPDX document for issues
     /// </summary>
+    /// <param name="context">Program context</param>
     /// <param name="spdxFile">SPDX document file name</param>
     /// <param name="ntia">NTIA flag</param>
     /// <exception cref="CommandErrorException">on issues</exception>
-    public static void DoValidate(string spdxFile, bool ntia)
+    public static void DoValidate(Context context, string spdxFile, bool ntia)
     {
         // Load the SPDX document
         var doc = SpdxHelpers.LoadJsonDocument(spdxFile);
@@ -119,12 +120,10 @@ public static void DoValidate(string spdxFile, bool ntia)
         if (issues.Count == 0)
             return;
 
-        // Report issues to console
-        Console.ForegroundColor = ConsoleColor.DarkYellow;
+        // Report issues
         foreach (var issue in issues)
-            Console.WriteLine(issue);
-        Console.ResetColor();
-        Console.WriteLine();
+            context.WriteWarning(issue);
+        context.WriteLine("");
         
         // Throw error
         throw new CommandErrorException($"Found {issues.Count} Issues in {spdxFile}");
diff --git a/src/DemaConsulting.SpdxTool/Context.cs b/src/DemaConsulting.SpdxTool/Context.cs
new file mode 100644
index 0000000..2a5c90b
--- /dev/null
+++ b/src/DemaConsulting.SpdxTool/Context.cs
@@ -0,0 +1,193 @@
+// Copyright (c) 2024 DEMA Consulting
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+namespace DemaConsulting.SpdxTool;
+
+/// <summary>
+///     Program Context class
+/// </summary>
+public sealed class Context : IDisposable
+{
+    /// <summary>
+    ///     Output log-file writer (when logging output to file)
+    /// </summary>
+    private readonly StreamWriter? _log;
+
+    /// <summary>
+    ///     Initializes a new instance of the Context class
+    /// </summary>
+    /// <param name="log">Optional log-file writer</param>
+    /// <param name="args">Program arguments</param>
+    private Context(StreamWriter? log, IReadOnlyCollection<string> args)
+    {
+        _log = log;
+        Arguments = args;
+    }
+
+    /// <summary>
+    ///     Gets a value indicating the version has been requested
+    /// </summary>
+    public bool Version { get; private init; }
+
+    /// <summary>
+    ///     Gets a value indicating help has been requested
+    /// </summary>
+    public bool Help { get; private init; }
+
+    /// <summary>
+    ///     Gets a value indicating silent-output has been requested
+    /// </summary>
+    public bool Silent { get; private init; }
+
+    /// <summary>
+    ///     Gets the arguments
+    /// </summary>
+    public IReadOnlyCollection<string> Arguments { get; private init; }
+
+    /// <summary>
+    ///     Gets the number of errors reported
+    /// </summary>
+    public int Errors { get; private set; }
+
+    /// <summary>
+    ///     Dispose of this context
+    /// </summary>
+    public void Dispose()
+    {
+        _log?.Dispose();
+    }
+
+    /// <summary>
+    ///     Write text to output
+    /// </summary>
+    /// <param name="text">Text to write</param>
+    public void WriteLine(string text)
+    {
+        // Write to the console unless silent
+        if (!Silent)
+            Console.WriteLine(text);
+
+        // Write to the log if specified
+        _log?.WriteLine(text);
+    }
+
+    /// <summary>
+    ///     Write warning message to output
+    /// </summary>
+    /// <param name="message">Warning message to write</param>
+    public void WriteWarning(string message)
+    {
+        // Write to the console unless silent
+        if (!Silent)
+        {
+            Console.ForegroundColor = ConsoleColor.DarkYellow;
+            Console.WriteLine(message);
+            Console.ResetColor();
+        }
+
+        // Write to the log if specified
+        _log?.WriteLine(message);
+    }
+
+    /// <summary>
+    ///     Write an error message to output
+    /// </summary>
+    /// <param name="message">Error message to write</param>
+    public void WriteError(string message)
+    {
+        // Write to the console unless silent
+        if (!Silent)
+        {
+            Console.ForegroundColor = ConsoleColor.Red;
+            Console.WriteLine(message);
+            Console.ResetColor();
+        }
+
+        // Write to the log if specified
+        _log?.WriteLine(message);
+
+        // Increment the number of errors
+        Errors++;
+    }
+
+    /// <summary>
+    ///     Create a program context
+    /// </summary>
+    /// <param name="args">Program arguments</param>
+    /// <returns>Program context</returns>
+    /// <exception cref="InvalidOperationException">Thrown on invalid arguments</exception>
+    public static Context Create(string[] args)
+    {
+        // Process arguments
+        var version = false;
+        var help = false;
+        var silent = false;
+        string? logFile = null;
+        var extra = new List<string>();
+        using var arg = args.AsEnumerable().GetEnumerator();
+        while (arg.MoveNext())
+        {
+            switch (arg.Current)
+            {
+                case "-v":
+                case "--version":
+                    // Handle version query
+                    version = true;
+                    break;
+
+                case "-h":
+                case "-?":
+                case "--help":
+                    // Handle help query
+                    help = true;
+                    break;
+
+                case "-s":
+                case "--silent":
+                    silent = true;
+                    break;
+
+                case "-l":
+                case "--log":
+                    // Handle logging output
+                    if (!arg.MoveNext())
+                        throw new InvalidOperationException("Missing log output filename");
+                    logFile = arg.Current;
+                    break;
+
+                default:
+                    // Handle unknown argument as start of extra parameters
+                    do
+                    {
+                        extra.Add(arg.Current);
+                    } while (arg.MoveNext());
+                    break;
+            }
+        }
+
+        // Return the new context
+        return new Context(logFile != null ? new StreamWriter(logFile) : null, extra.AsReadOnly())
+        {
+            Version = version,
+            Help = help,
+            Silent = silent
+        };
+    }
+}
\ No newline at end of file
diff --git a/src/DemaConsulting.SpdxTool/DemaConsulting.SpdxTool.csproj b/src/DemaConsulting.SpdxTool/DemaConsulting.SpdxTool.csproj
index ec4f9c1..ea1c00a 100644
--- a/src/DemaConsulting.SpdxTool/DemaConsulting.SpdxTool.csproj
+++ b/src/DemaConsulting.SpdxTool/DemaConsulting.SpdxTool.csproj
@@ -52,7 +52,7 @@
 
   <ItemGroup>
     <PackageReference Include="DemaConsulting.SpdxModel" Version="2.1.0" />
-    <PackageReference Include="YamlDotNet" Version="16.1.3" />
+    <PackageReference Include="YamlDotNet" Version="16.2.1" />
   </ItemGroup>
 
 </Project>
diff --git a/src/DemaConsulting.SpdxTool/Program.cs b/src/DemaConsulting.SpdxTool/Program.cs
index d7905ab..0b4ea52 100644
--- a/src/DemaConsulting.SpdxTool/Program.cs
+++ b/src/DemaConsulting.SpdxTool/Program.cs
@@ -38,97 +38,117 @@ public static class Program
             ?.InformationalVersion ?? "Unknown";
 
     /// <summary>
-    /// Application entry point
+    ///     Application entry point
     /// </summary>
     /// <param name="args">Program arguments</param>
     public static void Main(string[] args)
     {
-        // Handle querying for version
-        if (args.Length == 1 && (args[0] == "-v" || args[0] == "--version"))
+        try
+        {
+            using var context = Context.Create(args);
+            Run(context);
+            Environment.ExitCode = context.Errors > 0 ? 1 : 0;
+        }
+        catch (InvalidOperationException e)
+        {
+            // Report standard failure
+            Console.ForegroundColor = ConsoleColor.Red;
+            Console.WriteLine($"Error: {e.Message}");
+            Console.ResetColor();
+            Environment.Exit(1);
+        }
+        catch (Exception e)
+        {
+            Console.ForegroundColor = ConsoleColor.Red;
+            Console.WriteLine($"Error: {e}");
+            Console.ResetColor();
+            throw;
+        }
+    }
+
+    /// <summary>
+    ///     Run the program context
+    /// </summary>
+    /// <param name="context">Program context</param>
+    public static void Run(Context context)
+    {
+        // Handle version query
+        if (context.Version)
         {
-            Console.WriteLine(Version);
+            context.WriteLine(Version);
             return;
         }
 
         // Print version banner
-        Console.WriteLine($"DemaConsulting.SpdxTool {Version}\n");
+        context.WriteLine($"DemaConsulting.SpdxTool {Version}\n");
 
-        // Fail if no arguments specified
-        if (args.Length == 0)
+        // Handle help query
+        if (context.Help)
         {
-            ReportError("No arguments specified");
-            PrintUsage();
+            PrintUsage(context);
             return;
         }
 
-        // Handle printing usage information
-        if (args[0] == "-h" || args[0] == "--help")
+        // Handle missing arguments
+        if (context.Arguments.Count == 0)
         {
-            PrintUsage();
+            context.WriteError("Error: Missing arguments");
+            PrintUsage(context);
             return;
         }
 
         try
         {
-            if (CommandsRegistry.Commands.TryGetValue(args[0], out var entry))
+            var command = context.Arguments.First();
+            if (CommandsRegistry.Commands.TryGetValue(command, out var entry))
             {
                 // Run the command
-                entry.Instance.Run(args.Skip(1).ToArray());
+                entry.Instance.Run(context, context.Arguments.Skip(1).ToArray());
             }
             else
             {
                 // Report unknown command
-                ReportError($"Unknown command: '{args[0]}'");
-                PrintUsage();
+                context.WriteError($"Error: Unknown command '{command}'");
+                PrintUsage(context);
             }
         }
         catch (CommandUsageException ex)
         {
             // Report usage exception and usage information
-            ReportError(ex.Message);
-            PrintUsage();
+            context.WriteError($"Error: {ex.Message}");
+            PrintUsage(context);
         }
         catch (CommandErrorException ex)
         {
             // Report error exception
-            ReportError(ex.Message);
+            context.WriteError($"Error: {ex.Message}");
         }
         catch (Exception ex)
         {
             // Report unknown exception
-            ReportError(ex.ToString());
+            context.WriteError(ex.ToString());
         }
     }
 
     /// <summary>
-    /// Print usage information
+    ///     Print usage information
     /// </summary>
-    public static void PrintUsage()
+    /// <param name="context">Program context</param>
+    public static void PrintUsage(Context context)
     {
-        Console.WriteLine("Usage: spdx-tool [options] <command> [arguments]");
-        Console.WriteLine();
-        Console.WriteLine("Options:");
-        Console.WriteLine("  -h, --help                               Show this help message and exit");
-        Console.WriteLine("  -v, --version                            Show version information and exit");
-        Console.WriteLine();
-        Console.WriteLine("Commands:");
+        context.WriteLine(
+            """
+            Usage: spdx-tool [options] <command> [arguments]
+            
+            Options:
+              -h, --help                               Show this help message and exit
+              -v, --version                            Show version information and exit
+              -l, --log <log-file>                     Log output to file
+              -s, --silent                             Silence console output
+            
+            Commands:
+            """);
         foreach (var command in CommandsRegistry.Commands.Values)
-            Console.WriteLine($"  {command.CommandLine,-40} {command.Summary}");
-    }
-
-    /// <summary>
-    /// Report an error message to the console in red
-    /// </summary>
-    /// <param name="message">Error message</param>
-    private static void ReportError(string message)
-    {
-        // Write an error message to the console
-        Console.ForegroundColor = ConsoleColor.Red;
-        Console.WriteLine($"Error: {message}");
-        Console.ResetColor();
-        Console.WriteLine();
-
-        // Set the exit code to 1 as an error has occurred
-        Environment.ExitCode = 1;
+            context.WriteLine($"  {command.CommandLine,-40} {command.Summary}");
     }
 }
\ No newline at end of file
diff --git a/test/DemaConsulting.SpdxTool.Tests/DemaConsulting.SpdxTool.Tests.csproj b/test/DemaConsulting.SpdxTool.Tests/DemaConsulting.SpdxTool.Tests.csproj
index 7242e3a..ed5200d 100644
--- a/test/DemaConsulting.SpdxTool.Tests/DemaConsulting.SpdxTool.Tests.csproj
+++ b/test/DemaConsulting.SpdxTool.Tests/DemaConsulting.SpdxTool.Tests.csproj
@@ -19,9 +19,9 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
-    <PackageReference Include="MSTest.TestAdapter" Version="3.6.1" />
-    <PackageReference Include="MSTest.TestFramework" Version="3.6.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
+    <PackageReference Include="MSTest.TestAdapter" Version="3.6.3" />
+    <PackageReference Include="MSTest.TestFramework" Version="3.6.3" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/test/DemaConsulting.SpdxTool.Tests/TestLog.cs b/test/DemaConsulting.SpdxTool.Tests/TestLog.cs
new file mode 100644
index 0000000..9b3cc72
--- /dev/null
+++ b/test/DemaConsulting.SpdxTool.Tests/TestLog.cs
@@ -0,0 +1,94 @@
+// Copyright (c) 2024 DEMA Consulting
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+namespace DemaConsulting.SpdxTool.Tests;
+
+/// <summary>
+/// Tests for logging output.
+/// </summary>
+[TestClass]
+public class TestLog
+{
+    /// <summary>
+    /// Test that logging functions when '-l' is specified
+    /// </summary>
+    [TestMethod]
+    public void Log_Short()
+    {
+        try
+        {
+            // Run the command
+            var exitCode = Runner.Run(
+                out _,
+                "dotnet",
+                "DemaConsulting.SpdxTool.dll",
+                "-l", "output.log",
+                "-h");
+
+            // Verify success
+            Assert.AreEqual(0, exitCode);
+
+            // Assert log file written
+            Assert.IsTrue(File.Exists("output.log"));
+
+            // Verify the log contains the usage information
+            var log = File.ReadAllText("output.log");
+            StringAssert.Contains(log, "Usage: spdx-tool");
+        }
+        finally
+        {
+            // Delete output file
+            File.Delete("output.log");
+        }
+    }
+
+    /// <summary>
+    /// Test that logging functions when '--log' is specified
+    /// </summary>
+    [TestMethod]
+    public void Log_Long()
+    {
+        try
+        {
+            // Run the command
+            var exitCode = Runner.Run(
+                out _,
+                "dotnet",
+                "DemaConsulting.SpdxTool.dll",
+                "--log", "output.log",
+                "--help");
+
+            // Verify success
+            Assert.AreEqual(0, exitCode);
+
+            // Assert log file written
+            Assert.IsTrue(File.Exists("output.log"));
+
+            // Verify the log contains the usage information
+            var log = File.ReadAllText("output.log");
+            StringAssert.Contains(log, "Usage: spdx-tool");
+        }
+        finally
+        {
+            // Delete output file
+            File.Delete("output.log");
+        }
+    }
+}
\ No newline at end of file
diff --git a/test/DemaConsulting.SpdxTool.Tests/TestSilent.cs b/test/DemaConsulting.SpdxTool.Tests/TestSilent.cs
new file mode 100644
index 0000000..5f8c737
--- /dev/null
+++ b/test/DemaConsulting.SpdxTool.Tests/TestSilent.cs
@@ -0,0 +1,70 @@
+// Copyright (c) 2024 DEMA Consulting
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+namespace DemaConsulting.SpdxTool.Tests;
+
+/// <summary>
+/// Tests for silencing output.
+/// </summary>
+[TestClass]
+public class TestSilent
+{
+    /// <summary>
+    /// Test that silence functions when '-s' is specified
+    /// </summary>
+    [TestMethod]
+    public void Silent_Short()
+    {
+        // Run the command
+        var exitCode = Runner.Run(
+            out var output,
+            "dotnet",
+            "DemaConsulting.SpdxTool.dll",
+            "-s",
+            "-h");
+
+        // Verify success
+        Assert.AreEqual(0, exitCode);
+
+        // Verify the output is empty
+        Assert.AreEqual(0, output.Length);
+    }
+
+    /// <summary>
+    /// Test that silence functions when '--silent' is specified
+    /// </summary>
+    [TestMethod]
+    public void Silent_Long()
+    {
+        // Run the command
+        var exitCode = Runner.Run(
+            out var output,
+            "dotnet",
+            "DemaConsulting.SpdxTool.dll",
+            "--silent",
+            "--help");
+
+        // Verify success
+        Assert.AreEqual(0, exitCode);
+
+        // Verify the output is empty
+        Assert.AreEqual(0, output.Length);
+    }
+}
\ No newline at end of file
diff --git a/test/DemaConsulting.SpdxTool.Tests/TestUnknownCommand.cs b/test/DemaConsulting.SpdxTool.Tests/TestUnknownCommand.cs
index d31f6b5..04cf6e5 100644
--- a/test/DemaConsulting.SpdxTool.Tests/TestUnknownCommand.cs
+++ b/test/DemaConsulting.SpdxTool.Tests/TestUnknownCommand.cs
@@ -41,6 +41,6 @@ public void UnknownCommand()
 
         // Verify error reported
         Assert.AreEqual(1, exitCode);
-        StringAssert.Contains(output, "Unknown command: 'unknown-command'");
+        StringAssert.Contains(output, "Error: Unknown command 'unknown-command'");
     }
 }
\ No newline at end of file
diff --git a/test/DemaConsulting.SpdxTool.Tests/TestUsage.cs b/test/DemaConsulting.SpdxTool.Tests/TestUsage.cs
index d586cca..3f99d8e 100644
--- a/test/DemaConsulting.SpdxTool.Tests/TestUsage.cs
+++ b/test/DemaConsulting.SpdxTool.Tests/TestUsage.cs
@@ -42,7 +42,7 @@ public void Usage_NoArguments()
         Assert.AreEqual(1, exitCode);
 
         // Verify the output contains the usage information
-        StringAssert.Contains(output, "No arguments specified");
+        StringAssert.Contains(output, "Error: Missing arguments");
         StringAssert.Contains(output, "Usage: spdx-tool");
     }