Fix translator.

src/Infrastructure/BotSharp.Abstraction/Agents/Settings/AgentSettings.cs

@@ -5,6 +5,7 @@ public class AgentSettings
     public string DataDir { get; set; } = string.Empty;
     public string TemplateFormat { get; set; } = "liquid";
     public string HostAgentId { get; set; } = string.Empty;
+    public bool EnableTranslator { get; set; } = false;
 
     /// <summary>
     /// This is the default LLM config for agent

src/Infrastructure/BotSharp.Abstraction/Translation/Models/TranslationOutput.cs

@@ -0,0 +1,13 @@
+namespace BotSharp.Abstraction.Translation.Models;
+
+public class TranslationOutput
+{
+    [JsonPropertyName("input_lang")]
+    public string InputLanguage { get; set; } = null!;
+
+    [JsonPropertyName("output_lang")]
+    public string OutputLanguage { get; set; } = LanguageType.ENGLISH;
+
+    [JsonPropertyName("texts")]
+    public string[] Texts { get; set; } = Array.Empty<string>();
+}

src/Infrastructure/BotSharp.Core/Routing/Handlers/RouteToAgentRoutingHandler.cs

@@ -28,10 +28,7 @@ public class RouteToAgentRoutingHandler : RoutingHandlerBase, IRoutingHandler
             required: true),
         new ParameterPropertyDef("is_new_task",
             "whether the user is requesting a new task that is different from the previous topic.", 
-            type: "boolean"),
-        new ParameterPropertyDef("language",
-            "User preferred language, considering the whole conversation. Language could be English, Spanish or Chinese.", 
-            required: true)
+            type: "boolean")
     };
 
     public RouteToAgentRoutingHandler(IServiceProvider services, ILogger<RouteToAgentRoutingHandler> logger, RoutingSettings settings) 

src/Infrastructure/BotSharp.Core/Routing/RoutingService.GetConversationContent.cs

@@ -16,7 +16,7 @@ public partial class RoutingService
                 role = agent.Name;
             }
 
-            conversation += $"{role}: {dialog.Payload ?? dialog.SecondaryContent ?? dialog.Content}\r\n";
+            conversation += $"{role}: {dialog.Payload ?? dialog.Content}\r\n";
         }
 
         return conversation;

src/Infrastructure/BotSharp.Core/Routing/RoutingService.cs

@@ -82,26 +82,29 @@ public partial class RoutingService : IRoutingService
 
         _context.Push(_router.Id);
 
+        // Handle multi-language for input
+        var agentSettings = _services.GetRequiredService<AgentSettings>();
+        if (agentSettings.EnableTranslator)
+        {
+            var translator = _services.GetRequiredService<ITranslationService>();
+
+            var language = states.GetState("language", LanguageType.UNKNOWN);
+            if (language != LanguageType.ENGLISH)
+            {
+                message.SecondaryContent = message.Content;
+                message.Content = await translator.Translate(_router, message.MessageId, message.Content,
+                    language: LanguageType.ENGLISH,
+                    clone: false);
+            }
+        }
+
         dialogs.Add(message);
+        storage.Append(convService.ConversationId, message);
 
         // Get first instruction
         _router.TemplateDict["conversation"] = await GetConversationContent(dialogs);
         var inst = await planner.GetNextInstruction(_router, message.MessageId, dialogs);
 
-        // Handle multi-language for input
-        var translator = _services.GetRequiredService<ITranslationService>();
-
-        var language = states.GetState("language", inst.Language);
-        if (language != LanguageType.UNKNOWN && language != LanguageType.ENGLISH)
-        {
-            message.SecondaryContent = message.Content;
-            message.Content = await translator.Translate(_router, message.MessageId, message.Content,
-                language: LanguageType.ENGLISH,
-                clone: false);
-        }
-
-        storage.Append(convService.ConversationId, message);
-
         int loopCount = 1;
         while (true)
         {

src/Infrastructure/BotSharp.Core/Translation/TranslationResponseHook.cs

@@ -21,6 +21,12 @@ namespace BotSharp.Logger.Hooks
         }
         public override async Task OnResponseGenerated(RoleDialogModel message)
         {
+            var agentSettings = _services.GetRequiredService<AgentSettings>();
+            if (!agentSettings.EnableTranslator)
+            {
+                return;
+            }
+                
             // Handle multi-language for output
             var agentService = _services.GetRequiredService<IAgentService>();
             var router = await agentService.LoadAgent(AIAssistant);

src/Infrastructure/BotSharp.Core/Translation/TranslationService.cs

@@ -1,6 +1,8 @@
+using BotSharp.Abstraction.Infrastructures.Enums;
 using BotSharp.Abstraction.MLTasks;
 using BotSharp.Abstraction.Options;
 using BotSharp.Abstraction.Templating;
+using BotSharp.Abstraction.Translation.Models;
 using System.Collections;
 using System.Reflection;
 
@@ -57,7 +59,13 @@ public class TranslationService : ITranslationService
 
         try
         {
-            var translatedTexts = translatedStringList.JsonArrayContent<string>();
+            // Override language if it's Unknown, it's used to output the corresponding language.
+            var states = _services.GetRequiredService<IConversationStateService>();
+            var inputLanguage = string.IsNullOrEmpty(translatedStringList.InputLanguage) ? LanguageType.ENGLISH : translatedStringList.InputLanguage;
+            var languageState = states.GetState("language", inputLanguage);
+            states.SetState("language", languageState, activeRounds: 1);
+
+            var translatedTexts = translatedStringList.Texts;
             var map = new Dictionary<string, string>();
 
             for (var i = 0; i < texts.Length; i++)
@@ -283,7 +291,7 @@ public class TranslationService : ITranslationService
     /// <param name="list"></param>
     /// <param name="language"></param>
     /// <returns></returns>
-    private async Task<string> InnerTranslate(string texts, string language, string template)
+    private async Task<TranslationOutput> InnerTranslate(string texts, string language, string template)
     {
         var translator = new Agent
         {
@@ -308,7 +316,7 @@ public class TranslationService : ITranslationService
             }
         };
         var response = await _completion.GetChatCompletions(translator, translationDialogs);
-        return response.Content;
+        return response.Content.JsonContent<TranslationOutput>();
     }
 
     #region Type methods

src/Infrastructure/BotSharp.Core/data/agents/01fcc3e5-9af7-49e6-ad7a-a760bd12dc4a/templates/translation_prompt.liquid

@@ -1,4 +1,5 @@
 {{ text_list }}
 
 =====
-Translate the above sentences in the list into {{ language }}, output the translated text in JSON array [""].
+Translate the above sentences in the list into {{ language }}.
+Output the translated text in JSON {"input_lang":"",  "output_lang":"{{ language }}", "texts":[""]}, input_lang is based on the original sentences.