diff --git a/src/Infrastructure/BotSharp.Abstraction/Agents/IAgentService.cs b/src/Infrastructure/BotSharp.Abstraction/Agents/IAgentService.cs
index 503617666..7a06cce1d 100644
--- a/src/Infrastructure/BotSharp.Abstraction/Agents/IAgentService.cs
+++ b/src/Infrastructure/BotSharp.Abstraction/Agents/IAgentService.cs
@@ -2,6 +2,7 @@
 using BotSharp.Abstraction.Coding.Models;
 using BotSharp.Abstraction.Coding.Options;
 using BotSharp.Abstraction.Functions.Models;
+using BotSharp.Abstraction.Instructs.Enums;
 using BotSharp.Abstraction.Plugins.Models;
 using BotSharp.Abstraction.Repositories.Filters;
 
@@ -83,4 +84,5 @@ Task<bool> DeleteAgentCodeScripts(string agentId, List<AgentCodeScript>? codeScr
 
     Task<CodeGenerationResult> GenerateCodeScript(string agentId, string text, CodeGenHandleOptions? options = null)
         => Task.FromResult(new CodeGenerationResult());
+    ResponseFormatType GetTemplateResponseFormat(Agent agent, string templateName);
 }
diff --git a/src/Infrastructure/BotSharp.Abstraction/Instructs/Enums/ResponseFormatType.cs b/src/Infrastructure/BotSharp.Abstraction/Instructs/Enums/ResponseFormatType.cs
new file mode 100644
index 000000000..01186b30a
--- /dev/null
+++ b/src/Infrastructure/BotSharp.Abstraction/Instructs/Enums/ResponseFormatType.cs
@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace BotSharp.Abstraction.Instructs.Enums
+{
+    public enum ResponseFormatType
+    {
+        Text = 0,
+        Json = 1
+    }
+}
diff --git a/src/Infrastructure/BotSharp.Abstraction/Instructs/IInstructService.cs b/src/Infrastructure/BotSharp.Abstraction/Instructs/IInstructService.cs
index ab457f138..1c94e681e 100644
--- a/src/Infrastructure/BotSharp.Abstraction/Instructs/IInstructService.cs
+++ b/src/Infrastructure/BotSharp.Abstraction/Instructs/IInstructService.cs
@@ -1,3 +1,4 @@
+using BotSharp.Abstraction.Instructs.Enums;
 using BotSharp.Abstraction.Instructs.Models;
 using BotSharp.Abstraction.Instructs.Options;
 
@@ -20,7 +21,8 @@ Task<InstructResult> Execute(string agentId, RoleDialogModel message,
         string? instruction = null, string? templateName = null,
         IEnumerable<InstructFileModel>? files = null,
         CodeInstructOptions? codeOptions = null,
-        FileInstructOptions? fileOptions = null);
+        FileInstructOptions? fileOptions = null,
+        ResponseFormatType? responseFormat = null);
 
     /// <summary>
     /// A generic way to execute completion by using specified instruction or template
diff --git a/src/Infrastructure/BotSharp.Abstraction/Utilities/IJsonRepairService.cs b/src/Infrastructure/BotSharp.Abstraction/Utilities/IJsonRepairService.cs
new file mode 100644
index 000000000..833cd611b
--- /dev/null
+++ b/src/Infrastructure/BotSharp.Abstraction/Utilities/IJsonRepairService.cs
@@ -0,0 +1,23 @@
+namespace BotSharp.Abstraction.Utilities;
+
+/// <summary>
+/// Service for repairing malformed JSON using LLM.
+/// </summary>
+public interface IJsonRepairService
+{
+    /// <summary>
+    /// Repair malformed JSON and deserialize to target type.
+    /// </summary>
+    /// <typeparam name="T">Target type</typeparam>
+    /// <param name="malformedJson">The malformed JSON string</param>
+    /// <returns>Deserialized object or default if repair fails</returns>
+    Task<T?> RepairAndDeserialize<T>(string malformedJson);
+
+    /// <summary>
+    /// Repair malformed JSON string.
+    /// </summary>
+    /// <param name="malformedJson">The malformed JSON string</param>
+    /// <returns>Repaired JSON string</returns>
+    Task<string> Repair(string malformedJson);
+}
+
diff --git a/src/Infrastructure/BotSharp.Abstraction/Utilities/StringExtensions.cs b/src/Infrastructure/BotSharp.Abstraction/Utilities/StringExtensions.cs
index e26f663d1..6088ca46a 100644
--- a/src/Infrastructure/BotSharp.Abstraction/Utilities/StringExtensions.cs
+++ b/src/Infrastructure/BotSharp.Abstraction/Utilities/StringExtensions.cs
@@ -1,9 +1,10 @@
+using BotSharp.Abstraction.Options;
 using System.Text.Json;
 using System.Text.RegularExpressions;
 
 namespace BotSharp.Abstraction.Utilities;
 
-public static class StringExtensions
+public static partial class StringExtensions
 {
     public static string? IfNullOrEmptyAs(this string? str, string? defaultValue)
         => string.IsNullOrEmpty(str) ? defaultValue : str;
@@ -63,6 +64,23 @@ public static string CleanStr(this string? str)
         return str.Replace(" ", "").Replace("\t", "").Replace("\n", "").Replace("\r", "");
     }
 
+    [GeneratedRegex(@"[^\u0000-\u007F]")]
+    private static partial Regex NonAsciiCharactersRegex();
+
+    public static string CleanJsonStr(this string? str)
+    {
+        if (string.IsNullOrWhiteSpace(str)) return string.Empty;
+
+        str = str.Replace("```json", string.Empty).Replace("```", string.Empty).Trim();
+
+        return NonAsciiCharactersRegex().Replace(str, "");
+    }
+
+    public static T? Json<T>(this string text)
+    {
+        return JsonSerializer.Deserialize<T>(text, BotSharpOptions.defaultJsonOptions);
+    }
+
     public static string JsonContent(this string text)
     {
         var m = Regex.Match(text, @"\{(?:[^{}]|(?<open>\{)|(?<-open>\}))+(?(open)(?!))\}");
@@ -73,15 +91,7 @@ public static string JsonContent(this string text)
     {
         text = JsonContent(text);
 
-        var options = new JsonSerializerOptions
-        {
-            PropertyNameCaseInsensitive = true,
-            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
-            WriteIndented = true,
-            AllowTrailingCommas = true
-        };
-
-        return JsonSerializer.Deserialize<T>(text, options);
+        return JsonSerializer.Deserialize<T>(text, BotSharpOptions.defaultJsonOptions);
     }
 
     public static string JsonArrayContent(this string text)
@@ -94,15 +104,7 @@ public static string JsonArrayContent(this string text)
     {
         text = JsonArrayContent(text);
 
-        var options = new JsonSerializerOptions
-        {
-            PropertyNameCaseInsensitive = true,
-            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
-            WriteIndented = true,
-            AllowTrailingCommas = true
-        };
-
-        return JsonSerializer.Deserialize<T[]>(text, options);
+        return JsonSerializer.Deserialize<T[]>(text, BotSharpOptions.defaultJsonOptions);
     }
 
     public static bool IsPrimitiveValue(this string value)
diff --git a/src/Infrastructure/BotSharp.Core/Agents/Services/AgentService.Rendering.cs b/src/Infrastructure/BotSharp.Core/Agents/Services/AgentService.Rendering.cs
index 83e83ef5a..a897c552b 100644
--- a/src/Infrastructure/BotSharp.Core/Agents/Services/AgentService.Rendering.cs
+++ b/src/Infrastructure/BotSharp.Core/Agents/Services/AgentService.Rendering.cs
@@ -1,3 +1,4 @@
+using BotSharp.Abstraction.Instructs.Enums;
 using BotSharp.Abstraction.Loggers;
 using BotSharp.Abstraction.Templating;
 using Newtonsoft.Json.Linq;
@@ -7,6 +8,8 @@ namespace BotSharp.Core.Agents.Services;
 
 public partial class AgentService
 {
+    private const string JsonFormat = "Output Format (JSON only):";
+
     public string RenderInstruction(Agent agent, IDictionary<string, object>? renderData = null)
     {
         var render = _services.GetRequiredService<ITemplateRender>();
@@ -147,6 +150,14 @@ public string RenderTemplate(Agent agent, string templateName, IDictionary<strin
         return content;
     }
 
+    public ResponseFormatType GetTemplateResponseFormat(Agent agent, string templateName)
+    { 
+        if(string.IsNullOrEmpty(templateName)) return ResponseFormatType.Text;
+
+        var template = agent.Templates.FirstOrDefault(x => x.Name == templateName)?.Content ?? string.Empty;
+        return template.Contains(JsonFormat) ? ResponseFormatType.Json : ResponseFormatType.Text;
+    }
+
     public bool RenderVisibility(string? visibilityExpression, IDictionary<string, object> dict)
     {
         if (string.IsNullOrWhiteSpace(visibilityExpression))
diff --git a/src/Infrastructure/BotSharp.Core/BotSharp.Core.csproj b/src/Infrastructure/BotSharp.Core/BotSharp.Core.csproj
index 431c063e0..7f1d2ca93 100644
--- a/src/Infrastructure/BotSharp.Core/BotSharp.Core.csproj
+++ b/src/Infrastructure/BotSharp.Core/BotSharp.Core.csproj
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>$(TargetFramework)</TargetFramework>
@@ -290,4 +290,11 @@
       <Pack>true</Pack>
     </Content>
   </ItemGroup>
+
+  <ItemGroup>
+    <None Update="data\agents\01fcc3e5-9af7-49e6-ad7a-a760bd12dc4a\templates\json_repair.liquid">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+
 </Project>
diff --git a/src/Infrastructure/BotSharp.Core/Instructs/Services/InstructService.Execute.cs b/src/Infrastructure/BotSharp.Core/Instructs/Services/InstructService.Execute.cs
index f78832f3c..13112c2ad 100644
--- a/src/Infrastructure/BotSharp.Core/Instructs/Services/InstructService.Execute.cs
+++ b/src/Infrastructure/BotSharp.Core/Instructs/Services/InstructService.Execute.cs
@@ -5,6 +5,7 @@
 using BotSharp.Abstraction.Files.Options;
 using BotSharp.Abstraction.Files.Proccessors;
 using BotSharp.Abstraction.Instructs;
+using BotSharp.Abstraction.Instructs.Enums;
 using BotSharp.Abstraction.Instructs.Models;
 using BotSharp.Abstraction.Instructs.Options;
 using BotSharp.Abstraction.MLTasks;
@@ -21,7 +22,8 @@ public async Task<InstructResult> Execute(
         string? templateName = null,
         IEnumerable<InstructFileModel>? files = null,
         CodeInstructOptions? codeOptions = null,
-        FileInstructOptions? fileOptions = null)
+        FileInstructOptions? fileOptions = null,
+        ResponseFormatType? responseFormat = null)
     {
         var agentService = _services.GetRequiredService<IAgentService>();
         var agent = await agentService.LoadAgent(agentId);
@@ -52,7 +54,8 @@ public async Task<InstructResult> Execute(
             return codeResponse;
         }
 
-        response = await RunLlm(agent, message, instruction, templateName, files, fileOptions);
+        response = await RunLlm(agent, message, instruction, templateName, files, fileOptions, responseFormat);
+        
         return response;
     }
 
@@ -205,7 +208,8 @@ private async Task<InstructResult> RunLlm(
         string? instruction,
         string? templateName,
         IEnumerable<InstructFileModel>? files = null,
-        FileInstructOptions? fileOptions = null)
+        FileInstructOptions? fileOptions = null,
+        ResponseFormatType? responseFormat = null)
     {
         var agentService = _services.GetRequiredService<IAgentService>();
         var state = _services.GetRequiredService<IConversationStateService>();
@@ -290,6 +294,13 @@ private async Task<InstructResult> RunLlm(
             {
                 result = await GetChatCompletion(chatCompleter, agent, instruction, prompt, message.MessageId, files);
             }
+            // Repair JSON format if needed
+            responseFormat = responseFormat ?? agentService.GetTemplateResponseFormat(agent, templateName);
+            if (responseFormat == ResponseFormatType.Json)
+            {
+                var jsonRepairService = _services.GetRequiredService<IJsonRepairService>();
+                result = await jsonRepairService.Repair(result);
+            }
             response.Text = result;
         }
 
diff --git a/src/Infrastructure/BotSharp.Core/JsonRepair/JsonRepairPlugin.cs b/src/Infrastructure/BotSharp.Core/JsonRepair/JsonRepairPlugin.cs
new file mode 100644
index 000000000..73157984e
--- /dev/null
+++ b/src/Infrastructure/BotSharp.Core/JsonRepair/JsonRepairPlugin.cs
@@ -0,0 +1,19 @@
+using BotSharp.Abstraction.Plugins;
+using BotSharp.Abstraction.Utilities;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace BotSharp.Core.JsonRepair;
+
+public class JsonRepairPlugin : IBotSharpPlugin
+{
+    public string Id => "b2e8f9c4-6d5a-4f28-cbe1-cf8b92e344cb";
+    public string Name => "JSON Repair";
+    public string Description => "Repair malformed JSON using LLM";
+
+    public void RegisterDI(IServiceCollection services, IConfiguration config)
+    {
+        services.AddScoped<IJsonRepairService, JsonRepairService>();
+    }
+}
+
diff --git a/src/Infrastructure/BotSharp.Core/JsonRepair/JsonRepairService.cs b/src/Infrastructure/BotSharp.Core/JsonRepair/JsonRepairService.cs
new file mode 100644
index 000000000..257267119
--- /dev/null
+++ b/src/Infrastructure/BotSharp.Core/JsonRepair/JsonRepairService.cs
@@ -0,0 +1,113 @@
+using BotSharp.Abstraction.Templating;
+
+namespace BotSharp.Core.JsonRepair;
+
+/// <summary>
+/// Service for repairing malformed JSON using LLM.
+/// </summary>
+public class JsonRepairService : IJsonRepairService
+{
+    private readonly IServiceProvider _services;
+    private readonly ILogger<JsonRepairService> _logger;
+
+    private const string ROUTER_AGENT_ID = "01fcc3e5-9af7-49e6-ad7a-a760bd12dc4a";
+    private const string TEMPLATE_NAME = "json_repair";
+
+    public JsonRepairService(
+        IServiceProvider services,
+        ILogger<JsonRepairService> logger)
+    {
+        _services = services;
+        _logger = logger;
+    }
+
+    public async Task<string> Repair(string malformedJson)
+    {
+        var json = malformedJson.CleanJsonStr();
+        if (IsValidJson(json)) return json;
+
+        var repairedJson = await RepairByLLM(json);
+        if(IsValidJson(repairedJson)) return repairedJson;
+
+        // Try repairing again if still invalid
+        repairedJson = await RepairByLLM(json);
+
+        return IsValidJson(repairedJson) ? repairedJson : json;
+    }
+
+    public async Task<T?> RepairAndDeserialize<T>(string malformedJson)
+    {        
+        var json = await Repair(malformedJson);
+
+        return json.Json<T>();
+    }
+
+
+    private static bool IsValidJson(string malformedJson)
+    {
+        if (string.IsNullOrWhiteSpace(malformedJson))
+            return false;
+
+        try
+        {
+            JsonDocument.Parse(malformedJson);
+            return true;
+        }
+        catch (JsonException)
+        {
+            return false;
+        }
+    }
+
+    private async Task<string> RepairByLLM(string malformedJson)
+    {
+        var agentService = _services.GetRequiredService<IAgentService>();
+        var router = await agentService.GetAgent(ROUTER_AGENT_ID);
+        
+        var template = router.Templates?.FirstOrDefault(x => x.Name == TEMPLATE_NAME)?.Content;
+        if (string.IsNullOrEmpty(template))
+        {
+            _logger.LogWarning($"Template '{TEMPLATE_NAME}' not found in agent '{ROUTER_AGENT_ID}'");
+            return malformedJson;
+        }
+
+        var render = _services.GetRequiredService<ITemplateRender>();
+        var prompt = render.Render(template, new Dictionary<string, object>
+        {
+            { "input", malformedJson }
+        });
+
+        try
+        {
+            var completion = CompletionProvider.GetChatCompletion(_services,
+            provider: router?.LlmConfig?.Provider,
+            model: router?.LlmConfig?.Model);
+
+            var agent = new Agent
+            {
+                Id = Guid.Empty.ToString(),
+                Name = "JsonRepair",
+                Instruction = "You are a JSON repair expert."
+            };
+
+            var dialogs = new List<RoleDialogModel>
+        {
+            new RoleDialogModel(AgentRole.User, prompt)
+            {
+                FunctionName = TEMPLATE_NAME
+            }
+        };
+
+            var response = await completion.GetChatCompletions(agent, dialogs);
+
+            _logger.LogInformation($"JSON repair result: {response.Content}");
+            return response.Content.CleanJsonStr();
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to repair and deserialize JSON");
+            return malformedJson;
+        }        
+    }
+}
+
diff --git a/src/Infrastructure/BotSharp.Core/data/agents/01fcc3e5-9af7-49e6-ad7a-a760bd12dc4a/templates/json_repair.liquid b/src/Infrastructure/BotSharp.Core/data/agents/01fcc3e5-9af7-49e6-ad7a-a760bd12dc4a/templates/json_repair.liquid
new file mode 100644
index 000000000..7027aa598
--- /dev/null
+++ b/src/Infrastructure/BotSharp.Core/data/agents/01fcc3e5-9af7-49e6-ad7a-a760bd12dc4a/templates/json_repair.liquid
@@ -0,0 +1,3 @@
+Fix the malformed JSON below and output valid JSON only.
+
+{{ input }}
\ No newline at end of file
diff --git a/src/Infrastructure/BotSharp.OpenAPI/Controllers/Instruct/InstructModeController.cs b/src/Infrastructure/BotSharp.OpenAPI/Controllers/Instruct/InstructModeController.cs
index 8e439e66e..344f0758b 100644
--- a/src/Infrastructure/BotSharp.OpenAPI/Controllers/Instruct/InstructModeController.cs
+++ b/src/Infrastructure/BotSharp.OpenAPI/Controllers/Instruct/InstructModeController.cs
@@ -40,7 +40,8 @@ public async Task<InstructResult> InstructCompletion([FromRoute] string agentId,
             templateName: input.Template,
             files: input.Files,
             codeOptions: input.CodeOptions,
-            fileOptions: input.FileOptions);
+            fileOptions: input.FileOptions,
+            responseFormat: input.ResponseFormat);
 
         result.States = state.GetStates();
         return result; 
diff --git a/src/Infrastructure/BotSharp.OpenAPI/ViewModels/Instructs/Request/InstructMessageModel.cs b/src/Infrastructure/BotSharp.OpenAPI/ViewModels/Instructs/Request/InstructMessageModel.cs
index a56e29e11..8ccedfe07 100644
--- a/src/Infrastructure/BotSharp.OpenAPI/ViewModels/Instructs/Request/InstructMessageModel.cs
+++ b/src/Infrastructure/BotSharp.OpenAPI/ViewModels/Instructs/Request/InstructMessageModel.cs
@@ -1,3 +1,4 @@
+using BotSharp.Abstraction.Instructs.Enums;
 using BotSharp.Abstraction.Instructs.Options;
 
 namespace BotSharp.OpenAPI.ViewModels.Instructs;
@@ -13,6 +14,7 @@ public class InstructMessageModel : IncomingMessageModel
     public List<InstructFileModel>? Files { get; set; }
     public CodeInstructOptions? CodeOptions { get; set; }
     public FileInstructOptions? FileOptions { get; set; }
+    public ResponseFormatType? ResponseFormat { get; set; } = null;
 }
 
 
diff --git a/tests/BotSharp.LLM.Tests/Core/TestAgentService.cs b/tests/BotSharp.LLM.Tests/Core/TestAgentService.cs
index 06780627b..5e702fea9 100644
--- a/tests/BotSharp.LLM.Tests/Core/TestAgentService.cs
+++ b/tests/BotSharp.LLM.Tests/Core/TestAgentService.cs
@@ -3,6 +3,7 @@
 using BotSharp.Abstraction.Agents.Models;
 using BotSharp.Abstraction.Agents.Options;
 using BotSharp.Abstraction.Functions.Models;
+using BotSharp.Abstraction.Instructs.Enums;
 using BotSharp.Abstraction.Models;
 using BotSharp.Abstraction.Plugins.Models;
 using BotSharp.Abstraction.Repositories.Filters;
@@ -126,5 +127,10 @@ public IDictionary<string, object> CollectRenderData(Agent agent)
         {
             return new Dictionary<string, object>();
         }
+
+        public ResponseFormatType GetTemplateResponseFormat(Agent agent, string templateName)
+        {
+            return ResponseFormatType.Text;
+        }
     }
 }
\ No newline at end of file