Serve example

examples/LangChain.Samples.Serve/LangChain.Samples.Serve.csproj

@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.5.0" />
+    <PackageReference Include="Swashbuckle.AspNetCore.Swagger" Version="6.5.0" />
+    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerGen" Version="6.5.0" />
+    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerUI" Version="6.5.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\libs\LangChain.Core\LangChain.Core.csproj" />
+    <ProjectReference Include="..\..\src\libs\Providers\LangChain.Providers.Ollama\LangChain.Providers.Ollama.csproj" />
+    <ProjectReference Include="..\..\src\libs\Utilities\LangChain.Serve\LangChain.Serve.csproj" />
+  </ItemGroup>
+
+</Project>

examples/LangChain.Samples.Serve/Program.cs

@@ -0,0 +1,92 @@
+using LangChain.Memory;
+using LangChain.Providers;
+using LangChain.Providers.Ollama;
+using LangChain.Serve;
+using LangChain.Utilities.Classes.Repository;
+using static LangChain.Chains.Chain;
+using Message = LangChain.Providers.Message;
+
+
+var builder = WebApplication.CreateBuilder();
+
+
+
+// 1. Add LangChainServe
+builder.Services.AddLangChainServe();
+
+// 2. Create a model
+var model = new OllamaChatModel(new OllamaProvider(options:new OllamaOptions()
+{
+    Temperature = 0,
+    Stop = new[] { "User:" },
+}),"mistral:latest");
+
+
+// 3. Optional. Add custom name generator
+// After initiating conversation, this will generate a name for it
+// If skipped, the conversation will be stored with current datetime as a name
+builder.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(model);
+    return await chain.Run("text");
+
+});
+
+// 4. Optional. Add swagger to be able to test the API
+builder.Services.AddEndpointsApiExplorer();
+builder.Services.AddSwaggerGen();
+
+var app = builder.Build();
+
+// 5. Configure LangChainServe
+app.UseLangChainServe(options =>
+{
+    // Register a model. Can be called multiple times to register multiple models
+    // this will receive entire conversation and should return a response
+    options.RegisterModel("Test model", async (messages) =>
+    {
+        var template = @"You are helpful assistant. Keep your answers short.
+{chat_history}
+Assistant:";
+        // Convert messages to use with conversation buffer memory
+        var conversationBufferMemory = await ConvertToConversationBuffer(messages);
+        var chain = LoadMemory(conversationBufferMemory, "chat_history")
+                    | Template(template)
+                    | LLM(model);
+
+        // get response and send it as AI answer
+        var response = await chain.Run("text");
+        return new StoredMessage()
+        {
+            Author = MessageAuthor.AI,
+            Content = response
+        };
+    });
+});
+
+// 6. Optional. Add swagger middleware
+app.UseSwagger();
+app.UseSwaggerUI(c =>
+{
+    c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1");
+});
+app.Run();
+
+async Task<ConversationBufferMemory> ConvertToConversationBuffer(List<StoredMessage> list)
+{
+    var conversationBufferMemory = new ConversationBufferMemory();
+    conversationBufferMemory.Formatter.HumanPrefix = "User";
+    conversationBufferMemory.Formatter.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;
+}

examples/LangChain.Samples.Serve/Properties/launchSettings.json

@@ -0,0 +1,29 @@
+{
+  "$schema": "http://json.schemastore.org/launchsettings.json",
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:26462",
+      "sslPort": 0
+    }
+  },
+  "profiles": {
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "applicationUrl": "http://localhost:5000",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}

examples/LangChain.Samples.Serve/appsettings.Development.json

@@ -0,0 +1,8 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

examples/LangChain.Samples.Serve/appsettings.json

@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*"
+}