♻️ Replace the LangChain with Semantic Kernel

DysonNetwork.Insight/DysonNetwork.Insight.csproj

@@ -8,11 +8,9 @@
 
   <ItemGroup>
     <PackageReference Include="EFCore.NamingConventions" Version="9.0.0" />
-    <PackageReference Include="LangChain" Version="0.17.0" />
-    <PackageReference Include="LangChain.Databases.Postgres" Version="0.17.0" />
-    <PackageReference Include="LangChain.Serve" Version="0.17.0" />
-    <PackageReference Include="LangChain.Serve.OpenAI" Version="0.17.0" />
     <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="9.0.10" />
+    <PackageReference Include="Microsoft.SemanticKernel" Version="1.66.0" />
+    <PackageReference Include="Microsoft.SemanticKernel.Connectors.Ollama" Version="1.66.0-alpha" />
     <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="9.0.4" />
     <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL.NodaTime" Version="9.0.4" />
   </ItemGroup>

DysonNetwork.Insight/Program.cs

@@ -1,9 +1,7 @@
 using DysonNetwork.Insight;
 using DysonNetwork.Insight.Startup;
 using DysonNetwork.Shared.Http;
-using LangChain.Extensions.DependencyInjection;
 using Microsoft.EntityFrameworkCore;
-using LangChain.Serve;
 
 var builder = WebApplication.CreateBuilder(args);
 
@@ -17,7 +15,6 @@ builder.Services.AddAppAuthentication();
 builder.Services.AddAppFlushHandlers();
 builder.Services.AddAppBusinessServices();
 builder.Services.AddThinkingServices(builder.Configuration);
-builder.Services.AddLangChainServe();
 
 builder.AddSwaggerManifest(
     "DysonNetwork.Insight",
@@ -38,4 +35,4 @@ app.ConfigureAppMiddleware(builder.Configuration);
 
 app.UseSwaggerManifest("DysonNetwork.Insight");
 
-app.Run();
+app.Run();

DysonNetwork.Insight/Startup/ServiceCollectionExtensions.cs

@@ -2,13 +2,7 @@ using System.Text.Json;
 using System.Text.Json.Serialization;
 using DysonNetwork.Insight.Thinking;
 using DysonNetwork.Shared.Cache;
-using LangChain.Memory;
+using Microsoft.SemanticKernel;
-using LangChain.Serve;
-using LangChain.Serve.Abstractions.Repository;
-using LangChain.Serve.OpenAI;
-using static LangChain.Chains.Chain;
-using Message = LangChain.Providers.Message;
-using MessageRole = LangChain.Providers.MessageRole;
 using NodaTime;
 using NodaTime.Serialization.SystemTextJson;
 
@@ -71,45 +65,9 @@ public static class ServiceCollectionExtensions
 
     public static IServiceCollection AddThinkingServices(this IServiceCollection services, IConfiguration configuration)
     {
-        var modelProvider = new ThinkingProvider(configuration);
+        var thinkingProvider = new ThinkingProvider(configuration);
-        services.AddSingleton(modelProvider);
+        services.AddSingleton(thinkingProvider);
-
-        services.AddCustomNameGenerator(async messages =>
-        {
-            var template =
-                @"You will be given conversation between User and Assistant. Your task is to give name to this conversation using maximum 3 words
-Conversation:
-{chat_history}
-Your name: ";
-            var conversationBufferMemory = await ConvertToConversationBuffer(messages);
-            var chain = LoadMemory(conversationBufferMemory, "chat_history")
-                        | Template(template)
-                        | LLM(modelProvider.GetModel());
-
-            return await chain.RunAsync("text") ?? string.Empty;
-        });
 
         return services;
     }
-
+}
-    private static async Task<ConversationBufferMemory> ConvertToConversationBuffer(
-        IReadOnlyCollection<StoredMessage> list
-        )
-    {
-        var conversationBufferMemory = new ConversationBufferMemory
-        {
-            Formatter =
-            {
-                HumanPrefix = "User",
-                AiPrefix = "Assistant",
-            }
-        };
-        List<Message> converted = list
-            .Select(x => new Message(x.Content, x.Author == MessageAuthor.User ? MessageRole.Human : MessageRole.Ai))
-            .ToList();
-
-        await conversationBufferMemory.ChatHistory.AddMessages(converted);
-
-        return conversationBufferMemory;
-    }
-}

DysonNetwork.Insight/Thinking/ThinkingController.cs

@@ -1,8 +1,9 @@
 using System.ComponentModel.DataAnnotations;
-using LangChain.Providers;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.SemanticKernel.ChatCompletion;
 using System.Text;
-using CSharpToJsonSchema;
+using Microsoft.SemanticKernel;
+using Microsoft.SemanticKernel.Connectors.Ollama;
 
 namespace DysonNetwork.Insight.Thinking;
 
@@ -22,74 +23,42 @@ public class ThinkingController(ThinkingProvider provider) : ControllerBase
         Response.Headers.Append("Content-Type", "text/event-stream");
         Response.StatusCode = 200;
 
-        var model = provider.GetModel();
+        var kernel = provider.Kernel;
 
-        // Build conversation history (you may load from your memory store)
+        var chatCompletionService = kernel.GetRequiredService<IChatCompletionService>();
-        var messages = new List<Message>
-        {
-            new Message
-            {
-                Role = MessageRole.System,
-                Content =
-                    "You're a helpful assistant on the Solar Network, a social network. Your name is Sn-chan, a cute sweet heart with passion for almost everything."
-            },
-            new Message
-            {
-                Role = MessageRole.Human,
-                Content = request.UserMessage
-            }
-        };
 
-        // Mock tool definitions — you will replace these with your real tool calls
+        var chatHistory = new ChatHistory(
-        Func<string, Task<string>> getUserProfileAsync = async (userId) =>
+            "You're a helpful assistant on the Solar Network, a social network.\n" +
-        {
+            "Your name is Sn-chan, a cute sweet heart with passion for almost everything.\n" +
-            // MOCK: simulate fetching user profile
+            "\n" +
-            await Task.Delay(100); // simulate async work
+            "Your aim is to helping solving questions for the users on the Solar Network.\n" +
-            return $"{{\"userId\":\"{userId}\",\"name\":\"MockUser\",\"bio\":\"Loves music and tech.\"}}";
+            "And the Solar Network is the social network platform you live on.\n" +
-        };
+            "When the user ask questions about the Solar Network (also known as SN and Solian), try use the tools you have to get latest and accurate data."
-
+        );
-        Func<string, Task<string>> getRecentPostsAsync = async (topic) =>
+        chatHistory.AddUserMessage(request.UserMessage);
-        {
-            // MOCK: simulate fetching recent posts
-            await Task.Delay(200);
-            return
-                $"[{{\"postId\":\"p1\",\"topic\":\"{topic}\",\"content\":\"Mock post content 1.\"}} , {{\"postId\":\"p2\",\"topic\":\"{topic}\",\"content\":\"Mock post content 2.\"}}]";
-        };
-
-        // You might pass these tools into your model/agent context
-        // (Assuming your LangChain .NET version supports tool-binding; adapt as needed.)
 
         // Kick off streaming generation
         var accumulatedContent = new StringBuilder();
-        await foreach (var chunk in model.GenerateAsync(
+        await foreach (var chunk in chatCompletionService.GetStreamingChatMessageContentsAsync(
-                           new ChatRequest
+                           chatHistory,
+                           new OllamaPromptExecutionSettings
                            {
-                               Messages = messages,
+                               FunctionChoiceBehavior = FunctionChoiceBehavior.Auto(
-                               Tools =
+                                   options: new FunctionChoiceBehaviorOptions()
-                               [
-                                   new Tool
                                    {
-                                       Name = "get_user_profile",
+                                       AllowParallelCalls = true,
-                                       Description = "Get a user profile from the Solar Network."
+                                       AllowConcurrentInvocation = true
-                                   },
+                                   })
-                                   new Tool
-                                   {
-                                       Name = "get_recent_posts",
-                                       Description = "Get recent posts from the Solar Network."
-                                   }
-                               ]
                            },
-                           new ChatSettings { UseStreaming = true }
+                           kernel: kernel
                        ))
         {
             // Write each chunk to the HTTP response as SSE
-            var data = chunk.LastMessageContent;
+            var data = chunk.Content ?? "";
             accumulatedContent.Append(data);
-            var sb = new StringBuilder();
+            if (string.IsNullOrEmpty(data)) continue;
-            sb.Append("data: ");
+
-            sb.AppendLine(accumulatedContent.ToString().Replace("\n", "\ndata: "));
+            var bytes = Encoding.UTF8.GetBytes(data);
-            sb.AppendLine(); // the blank line terminates the chunk
-            var bytes = Encoding.UTF8.GetBytes(sb.ToString());
             await Response.Body.WriteAsync(bytes);
             await Response.Body.FlushAsync();
         }

DysonNetwork.Insight/Thinking/ThinkingProvider.cs

@@ -1,11 +1,10 @@
-using LangChain.Providers;
+using Microsoft.SemanticKernel;
-using LangChain.Providers.Ollama;
 
 namespace DysonNetwork.Insight.Thinking;
 
 public class ThinkingProvider
 {
-    public readonly Provider Provider;
+    public readonly Kernel Kernel;
     public readonly string? ModelProviderType;
     public readonly string? ModelDefault;
 
@@ -13,25 +12,37 @@ public class ThinkingProvider
     {
         var cfg = configuration.GetSection("Thinking");
         ModelProviderType = cfg.GetValue<string>("Provider")?.ToLower();
+        ModelDefault = cfg.GetValue<string>("Model");
+        var endpoint = cfg.GetValue<string>("Endpoint");
+
+        var builder = Kernel.CreateBuilder();
+
         switch (ModelProviderType)
         {
             case "ollama":
-                var endpoint = cfg.GetValue<string>("Endpoint");
+                builder.AddOllamaChatCompletion(ModelDefault!, new Uri(endpoint ?? "http://localhost:11434/api"));
-                Provider = new OllamaProvider(endpoint ?? "http://localhost:11434/api");
                 break;
             default:
                 throw new IndexOutOfRangeException("Unknown thinking provider: " + ModelProviderType);
         }
 
-        ModelDefault = cfg.GetValue<string>("Model");
+        Kernel = builder.Build();
-    }
 
-    public ChatModel GetModel(string? name = null)
+        // Add Solar Network tools plugin
-    {
+        Kernel.ImportPluginFromFunctions("helper_functions", [
-        return ModelProviderType switch
+            KernelFunctionFactory.CreateFromMethod(async (string userId) =>
-        {
+            {
-            "ollama" => new OllamaChatModel((Provider as OllamaProvider)!, (name ?? ModelDefault)!),
+                // MOCK: simulate fetching user profile
-            _ => throw new IndexOutOfRangeException("Unknown thinking provider: " + ModelProviderType),
+                await Task.Delay(100);
-        };
+                return $"{{\"userId\":\"{userId}\",\"name\":\"MockUser\",\"bio\":\"Loves music and tech.\"}}";
+            }, "get_user_profile", "Get a user profile from the Solar Network."),
+            KernelFunctionFactory.CreateFromMethod(async (string topic) =>
+            {
+                // MOCK: simulate fetching recent posts
+                await Task.Delay(200);
+                return
+                    $"[{{\"postId\":\"p1\",\"topic\":\"{topic}\",\"content\":\"Mock post content 1.\"}}, {{\"postId\":\"p2\",\"topic\":\"{topic}\",\"content\":\"Mock post content 2.\"}}]";
+            }, "get_recent_posts", "Get recent posts from the Solar Network.")
+        ]);
     }
 }