Add --log-for human|machine flag for LLM/agent-friendly output

DevProxy.Abstractions/Proxy/IProxyConfiguration.cs

@@ -18,6 +18,14 @@ public enum ReleaseType
     Beta
 }
 
+public enum LogFor
+{
+    [EnumMember(Value = "human")]
+    Human,
+    [EnumMember(Value = "machine")]
+    Machine
+}
+
 public interface IProxyConfiguration
 {
     int ApiPort { get; set; }
@@ -29,6 +37,7 @@ public interface IProxyConfiguration
     IEnumerable<MockRequestHeader>? FilterByHeaders { get; }
     bool InstallCert { get; set; }
     string? IPAddress { get; set; }
+    LogFor LogFor { get; set; }
     LogLevel LogLevel { get; }
     ReleaseType NewVersionNotification { get; }
     bool NoFirstRun { get; set; }

DevProxy.Plugins/SharePoint/CsomParser.cs

@@ -80,7 +80,7 @@ public static (IEnumerable<string> Actions, IEnumerable<string> Errors) GetActio
         }
         catch (Exception ex)
         {
-            Console.WriteLine($"Error parsing XML: {ex.Message}");
+            errors.Add($"Error parsing XML: {ex.Message}");
         }
 
         return (actions, errors);

DevProxy/Commands/DevProxyCommand.cs

@@ -37,6 +37,7 @@ sealed class DevProxyCommand : RootCommand
     internal const string TimeoutOptionName = "--timeout";
     internal const string DiscoverOptionName = "--discover";
     internal const string EnvOptionName = "--env";
+    internal const string LogForOptionName = "--log-for";
 
     private static readonly string[] globalOptions = ["--version"];
     private static readonly string[] helpOptions = ["--help", "-h", "/h", "-?", "/?"];
@@ -396,6 +397,24 @@ private void ConfigureCommand()
             }
         });
 
+        var logForOption = new Option<LogFor?>(LogForOptionName)
+        {
+            Description = $"Target audience for log output. Allowed values: {string.Join(", ", Enum.GetNames<LogFor>())}",
+            HelpName = "log-for",
+            Recursive = true
+        };
+        logForOption.Validators.Add(input =>
+        {
+            if (input.Tokens.Count == 0)
+            {
+                return;
+            }
+            if (!Enum.TryParse<LogFor>(input.Tokens[0].Value, true, out _))
+            {
+                input.AddError($"{input.Tokens[0].Value} is not a valid log-for value. Allowed values are: {string.Join(", ", Enum.GetNames<LogFor>())}");
+            }
+        });
+
         var options = new List<Option>
         {
             apiPortOption,
@@ -405,6 +424,7 @@ private void ConfigureCommand()
             envOption,
             installCertOption,
             ipAddressOption,
+            logForOption,
             logLevelOption,
             noFirstRunOption,
             portOption,
@@ -505,6 +525,11 @@ private void ConfigureFromOptions(ParseResult parseResult)
                     : new KeyValuePair<string, string>(parts[0], parts[1]);
             }).ToDictionary(kvp => kvp.Key, kvp => kvp.Value);
         }
+        var logFor = parseResult.GetValueOrDefault<LogFor?>(LogForOptionName);
+        if (logFor is not null)
+        {
+            _proxyConfiguration.LogFor = logFor.Value;
+        }
     }
 
     private async Task CheckForNewVersionAsync()

DevProxy/Commands/DevProxyConfigOptions.cs

@@ -1,3 +1,4 @@
+using DevProxy.Abstractions.Proxy;
 using DevProxy.Abstractions.Utils;
 using System.CommandLine;
 using System.CommandLine.Parsing;
@@ -20,6 +21,7 @@ public string? ConfigFile
     public int? ApiPort => _parseResult?.GetValueOrDefault<int?>(DevProxyCommand.ApiPortOptionName);
     public bool Discover => _parseResult?.GetValueOrDefault<bool?>(DevProxyCommand.DiscoverOptionName) ?? false;
     public string? IPAddress => _parseResult?.GetValueOrDefault<string?>(DevProxyCommand.IpAddressOptionName);
+    public LogFor? LogFor => _parseResult?.GetValueOrDefault<LogFor?>(DevProxyCommand.LogForOptionName);
     public LogLevel? LogLevel => _parseResult?.GetValueOrDefault<LogLevel?>(DevProxyCommand.LogLevelOptionName);
 
     public List<string>? UrlsToWatch
@@ -114,6 +116,25 @@ public DevProxyConfigOptions()
                 }
             }
         };
+
+        var logForOption = new Option<LogFor?>(DevProxyCommand.LogForOptionName)
+        {
+            CustomParser = result =>
+            {
+                if (!result.Tokens.Any())
+                {
+                    return null;
+                }
+
+                if (Enum.TryParse<LogFor>(result.Tokens[0].Value, true, out var logFor))
+                {
+                    return logFor;
+                }
+
+                return null;
+            }
+        };
+
         var apiPortOption = new Option<int?>(DevProxyCommand.ApiPortOptionName);
 
         var discoverOption = new Option<bool>(DevProxyCommand.DiscoverOptionName, "--discover")
@@ -127,6 +148,7 @@ public DevProxyConfigOptions()
             ipAddressOption,
             configFileOption,
             urlsToWatchOption,
+            logForOption,
             logLevelOption,
             discoverOption
         };

DevProxy/Extensions/ILoggingBuilderExtensions.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using DevProxy.Abstractions.Proxy;
 using DevProxy.Commands;
 using DevProxy.Logging;
 
@@ -26,6 +27,10 @@ public static ILoggingBuilder ConfigureDevProxyLogging(
         var configuredLogLevel = options.LogLevel ??
             configuration.GetValue("logLevel", LogLevel.Information);
 
+        // Determine the log target audience (human or machine)
+        var configuredLogFor = options.LogFor ??
+            configuration.GetValue("logFor", LogFor.Human);
+
         // For stdio command, log to file instead of console to avoid interfering with proxied streams
         if (DevProxyCommand.IsStdioCommand)
         {
@@ -48,6 +53,14 @@ public static ILoggingBuilder ConfigureDevProxyLogging(
             return builder;
         }
 
+        var showSkipMessages = configuration.GetValue("showSkipMessages", true);
+        var showTimestamps = configuration.GetValue("showTimestamps", true);
+
+        // Select the appropriate formatter based on logFor setting
+        var formatterName = configuredLogFor == LogFor.Machine
+            ? MachineConsoleFormatter.FormatterName
+            : ProxyConsoleFormatter.DefaultCategoryName;
+
         // For root command (proxy itself), use rich logging
         if (DevProxyCommand.IsRootCommand)
         {
@@ -60,17 +73,24 @@ public static ILoggingBuilder ConfigureDevProxyLogging(
                 .AddFilter("DevProxy.Plugins.*", level =>
                     level >= configuredLogLevel &&
                     !DevProxyCommand.HasGlobalOptions)
-                .AddConsole(options =>
+                .AddConsole(consoleOptions =>
                     {
-                        options.FormatterName = ProxyConsoleFormatter.DefaultCategoryName;
-                        options.LogToStandardErrorThreshold = LogLevel.Warning;
+                        consoleOptions.FormatterName = formatterName;
+                        consoleOptions.LogToStandardErrorThreshold = LogLevel.Warning;
                     }
                 )
-                .AddConsoleFormatter<ProxyConsoleFormatter, ProxyConsoleFormatterOptions>(options =>
+                .AddConsoleFormatter<ProxyConsoleFormatter, ProxyConsoleFormatterOptions>(formatterOptions =>
                     {
-                        options.IncludeScopes = true;
-                        options.ShowSkipMessages = configuration.GetValue("showSkipMessages", true);
-                        options.ShowTimestamps = configuration.GetValue("showTimestamps", true);
+                        formatterOptions.IncludeScopes = true;
+                        formatterOptions.ShowSkipMessages = showSkipMessages;
+                        formatterOptions.ShowTimestamps = showTimestamps;
+                    }
+                )
+                .AddConsoleFormatter<MachineConsoleFormatter, ProxyConsoleFormatterOptions>(formatterOptions =>
+                    {
+                        formatterOptions.IncludeScopes = true;
+                        formatterOptions.ShowSkipMessages = showSkipMessages;
+                        formatterOptions.ShowTimestamps = showTimestamps;
                     }
                 )
                 .AddRequestLogger()
@@ -86,17 +106,24 @@ public static ILoggingBuilder ConfigureDevProxyLogging(
             .AddFilter("Microsoft.Extensions.*", LogLevel.Error)
             .AddFilter("System.*", LogLevel.Error)
             .AddFilter("DevProxy.Plugins.*", LogLevel.None)
-            .AddConsole(options =>
+            .AddConsole(consoleOptions =>
+                {
+                    consoleOptions.FormatterName = formatterName;
+                    consoleOptions.LogToStandardErrorThreshold = LogLevel.Warning;
+                }
+            )
+            .AddConsoleFormatter<ProxyConsoleFormatter, ProxyConsoleFormatterOptions>(formatterOptions =>
                 {
-                    options.FormatterName = ProxyConsoleFormatter.DefaultCategoryName;
-                    options.LogToStandardErrorThreshold = LogLevel.Warning;
+                    formatterOptions.IncludeScopes = true;
+                    formatterOptions.ShowSkipMessages = showSkipMessages;
+                    formatterOptions.ShowTimestamps = showTimestamps;
                 }
             )
-            .AddConsoleFormatter<ProxyConsoleFormatter, ProxyConsoleFormatterOptions>(options =>
+            .AddConsoleFormatter<MachineConsoleFormatter, ProxyConsoleFormatterOptions>(formatterOptions =>
                 {
-                    options.IncludeScopes = true;
-                    options.ShowSkipMessages = configuration.GetValue("showSkipMessages", true);
-                    options.ShowTimestamps = configuration.GetValue("showTimestamps", true);
+                    formatterOptions.IncludeScopes = true;
+                    formatterOptions.ShowSkipMessages = showSkipMessages;
+                    formatterOptions.ShowTimestamps = showTimestamps;
                 }
             )
             .SetMinimumLevel(configuredLogLevel);