autogen/dotnet/website/tutorial/Chat-with-an-agent.md

This tutorial shows how to generate response using an @AutoGen.Core.IAgent by taking @AutoGen.OpenAI.OpenAIChatAgent as an example.

> [!NOTE]
> AutoGen.Net provides the following agents to connect to different LLM platforms. Generating responses using these agents is similar to the example shown below.
> - @AutoGen.OpenAI.OpenAIChatAgent
> - @AutoGen.SemanticKernel.SemanticKernelAgent
> - @AutoGen.LMStudio.LMStudioAgent
> - @AutoGen.Mistral.MistralClientAgent
> - @AutoGen.Anthropic.AnthropicClientAgent
> - @AutoGen.Ollama.OllamaAgent
> - @AutoGen.Gemini.GeminiChatAgent

> [!NOTE]
> The complete code example can be found in [Chat_With_Agent.cs](https://github.com/microsoft/autogen/blob/main/dotnet/samples/AgentChat/Autogen.Basic.Sample/GettingStart/Chat_With_Agent.cs)

## Step 1: Install AutoGen

First, install the AutoGen package using the following command:

```bash
dotnet add package AutoGen
```

## Step 2: add Using Statements

[!code-csharp[Using Statements](../../samples/AgentChat/Autogen.Basic.Sample/GettingStart/Chat_With_Agent.cs?name=Using)]

## Step 3: Create an @AutoGen.OpenAI.OpenAIChatAgent

> [!NOTE]
> The @AutoGen.OpenAI.Extension.OpenAIAgentExtension.RegisterMessageConnector* method registers an @AutoGen.OpenAI.OpenAIChatRequestMessageConnector middleware which converts OpenAI message types to AutoGen message types. This step is necessary when you want to use AutoGen built-in message types like @AutoGen.Core.TextMessage, @AutoGen.Core.ImageMessage, etc.
> For more information, see [Built-in-messages](../articles/Built-in-messages.md)

[!code-csharp[Create an OpenAIChatAgent](../../samples/AgentChat/Autogen.Basic.Sample/GettingStart/Chat_With_Agent.cs?name=Create_Agent)]

## Step 4: Generate Response
To generate response, you can use one of the overloaded method of @AutoGen.Core.AgentExtension.SendAsync* method. The following code shows how to generate response with text message:

[!code-csharp[Generate Response](../../samples/AgentChat/Autogen.Basic.Sample/GettingStart/Chat_With_Agent.cs?name=Chat_With_Agent)]

To generate response with chat history, you can pass the chat history to the @AutoGen.Core.AgentExtension.SendAsync* method:

[!code-csharp[Generate Response with Chat History](../../samples/AgentChat/Autogen.Basic.Sample/GettingStart/Chat_With_Agent.cs?name=Chat_With_History)]

To streamingly generate response, use @AutoGen.Core.IStreamingAgent.GenerateStreamingReplyAsync*

[!code-csharp[Generate Streaming Response](../../samples/AgentChat/Autogen.Basic.Sample/GettingStart/Chat_With_Agent.cs?name=Streaming_Chat)]

## Further Reading
- [Chat with google gemini](../articles/AutoGen.Gemini/Chat-with-google-gemini.md)
- [Chat with vertex gemini](../articles/AutoGen.Gemini/Chat-with-vertex-gemini.md)
- [Chat with Ollama](../articles/AutoGen.Ollama/Chat-with-llama.md)
- [Chat with Semantic Kernel Agent](../articles/AutoGen.SemanticKernel/SemanticKernelAgent-simple-chat.md)