Message Types and Session History in C#

Message Types and Session History

Welcome back! In the previous lessons, you learned how to send a simple query to DeepSeek's language model and explored various model parameters to customize the AI's responses. Now, we will delve into the concept of message types and the importance of maintaining session history . These elements are crucial for creating dynamic and context-aware interactions with the AI, allowing your personal tutor to engage in more meaningful educational conversations.

Understanding Message Types

Creating a Method to Handle Tutoring Sessions

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public class Message
{
    public string role { get; set; }
    public string content { get; set; }

    public Message(string role, string content)
    {
        this.role = role;
        this.content = content;
    }
}

// Example session history
var session = new List<Message>
{
    new Message("user", "Can you explain the theory of relativity?"),
    new Message("assistant", "Einstein's theory of relativity consists of two parts: special relativity and general relativity..."),
    new Message("user", "What practical applications does it have?"),
    new Message("assistant", "The theory of relativity has several practical applications including GPS systems, particle accelerators, and understanding astronomical phenomena.")
};

private static async Task<string> SendMessage(string endpoint, string apiKey, List<Message> conversation, string userMessage)
{
    // Append the user's message to the conversation history
    conversation.Add(new Message("user", userMessage));

    using var client = new HttpClient();
    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);

    var payload = new
    {
        model = "deepseek-ai/DeepSeek-V3",
        messages = conversation
    };

    var jsonPayload = JsonSerializer.Serialize(payload);
    using var content = new StringContent(jsonPayload, Encoding.UTF8, "application/json");
    var response = await client.PostAsync(endpoint, content);
    var body = await response.Content.ReadAsStringAsync();

    if (!response.IsSuccessStatusCode)
    {
        Console.WriteLine($"Error ({response.StatusCode}): {body}");
        return "";
    }

    using var doc = JsonDocument.Parse(body);
    var reply = doc.RootElement
                   .GetProperty("choices")[0]
                   .GetProperty("message")
                   .GetProperty("content")
                   .GetString();

    // Append the AI's response to the conversation history
    conversation.Add(new Message("assistant", reply?.Trim() ?? ""));

    return reply?.Trim() ?? "";
}

private static async Task<string> SendMessage(string endpoint, string apiKey, List<Message> conversation, string userMessage)
{
    // Append the user's message to the conversation history
    conversation.Add(new Message("user", userMessage));

    using var client = new HttpClient();
    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);

    var payload = new
    {
        model = "deepseek-ai/DeepSeek-V3",
        messages = conversation
    };

    var jsonPayload = JsonSerializer.Serialize(payload);
    using var content = new StringContent(jsonPayload, Encoding.UTF8, "application/json");
    var response = await client.PostAsync(endpoint, content);
    var body = await response.Content.ReadAsStringAsync();

    if (!response.IsSuccessStatusCode)
    {
        Console.WriteLine($"Error ({response.StatusCode}): {body}");
        return "";
    }

    using var doc = JsonDocument.Parse(body);
    var reply = doc.RootElement
                   .GetProperty("choices")[0]
                   .GetProperty("message")
                   .GetProperty("content")
                   .GetString();

    // Append the AI's response to the conversation history
    conversation.Add(new Message("assistant", reply?.Trim() ?? ""));

    return reply?.Trim() ?? "";
}

public class Program
{
    public static async Task Main(string[] args)
    {
        var apiKey = Environment.GetEnvironmentVariable("OPENAI_API_KEY");
        var baseUri = Environment.GetEnvironmentVariable("OPENAI_BASE_URL");
        if (string.IsNullOrEmpty(apiKey))
        {
            Console.WriteLine("Set your OPENAI_API_KEY.");
            return;
        }
        if (string.IsNullOrEmpty(baseUri))
        {
            Console.WriteLine("Set your OPENAI_BASE_URL (e.g. https://api.openai.com).");
            return;
        }

        var endpoint = baseUri.TrimEnd('/') + "/v1/chat/completions";

        // Start a session with an initial query
        var session = new List<Message>();

        // Get first response
        string reply = await SendMessage(endpoint, apiKey, session, "What was the most notable achievement of Albert Einstein?");
        Console.WriteLine("Answer: " + reply);

        // Add a follow-up query and get explanation with tutoring context
        string followUpReply = await SendMessage(endpoint, apiKey, session, "Can you provide three more examples?");
        Console.WriteLine("Follow-up: " + followUpReply);
    }
}

public class Program
{
    public static async Task Main(string[] args)
    {
        var apiKey = Environment.GetEnvironmentVariable("OPENAI_API_KEY");
        var baseUri = Environment.GetEnvironmentVariable("OPENAI_BASE_URL");
        if (string.IsNullOrEmpty(apiKey))
        {
            Console.WriteLine("Set your OPENAI_API_KEY.");
            return;
        }
        if (string.IsNullOrEmpty(baseUri))
        {
            Console.WriteLine("Set your OPENAI_BASE_URL (e.g. https://api.openai.com).");
            return;
        }

        var endpoint = baseUri.TrimEnd('/') + "/v1/chat/completions";

        // Start a session with an initial query
        var session = new List<Message>();

        // Get first response
        string reply = await SendMessage(endpoint, apiKey, session, "What was the most notable achievement of Albert Einstein?");
        Console.WriteLine("Answer: " + reply);

        // Add a follow-up query and get explanation with tutoring context
        string followUpReply = await SendMessage(endpoint, apiKey, session, "Can you provide three more examples?");
        Console.WriteLine("Follow-up: " + followUpReply);
    }
}

text

Answer: Albert Einstein's most notable achievement is generally considered to be his theory of relativity, particularly the general theory of relativity published in 1915...

Answer: Albert Einstein's most notable achievement is generally considered to be his theory of relativity, particularly the general theory of relativity published in 1915...

text

Follow-up: Here are three more notable achievements of Albert Einstein:

1. Photoelectric Effect: In 1905, Einstein explained the photoelectric effect, demonstrating that light consists of particles called photons...

2. Einstein's Theory of Brownian Motion: Also in 1905, Einstein provided mathematical evidence for the existence of atoms...

3. Mass-Energy Equivalence: Einstein formulated the equation E=mc²...

Follow-up: Here are three more notable achievements of Albert Einstein:

1. Photoelectric Effect: In 1905, Einstein explained the photoelectric effect, demonstrating that light consists of particles called photons...

2. Einstein's Theory of Brownian Motion: Also in 1905, Einstein provided mathematical evidence for the existence of atoms...

3. Mass-Energy Equivalence: Einstein formulated the equation E=mc²...

// Iterate over the conversation history and print each message
foreach (var message in session)
{
    Console.WriteLine($"{Capitalize(message.role)}: {message.content}");
}

// Helper method to capitalize the first letter
private static string Capitalize(string input)
{
    if (string.IsNullOrEmpty(input)) return input;
    return char.ToUpper(input[0]) + input.Substring(1);
}

// Iterate over the conversation history and print each message
foreach (var message in session)
{
    Console.WriteLine($"{Capitalize(message.role)}: {message.content}");
}

// Helper method to capitalize the first letter
private static string Capitalize(string input)
{
    if (string.IsNullOrEmpty(input)) return input;
    return char.ToUpper(input[0]) + input.Substring(1);
}

text

User: What was the most notable achievement of Albert Einstein?
Assistant: Albert Einstein's most notable achievement is generally considered to be his theory of relativity...
User: Can you provide three more examples?
Assistant: Here are three more notable achievements of Albert Einstein: 1. Photoelectric Effect... 2. Einstein's Theory of Brownian Motion... 3. Mass-Energy Equivalence...

User: What was the most notable achievement of Albert Einstein?
Assistant: Albert Einstein's most notable achievement is generally considered to be his theory of relativity...
User: Can you provide three more examples?
Assistant: Here are three more notable achievements of Albert Einstein: 1. Photoelectric Effect... 2. Einstein's Theory of Brownian Motion... 3. Mass-Energy Equivalence...

private static async Task<string> SendMessage(string endpoint, string apiKey, List<Message> conversation, string userMessage)
{
    // Append the user's message to the conversation history
    conversation.Add(new Message("user", userMessage));

    using var client = new HttpClient();
    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);

    var payload = new
    {
        model = "deepseek-ai/DeepSeek-V3",
        messages = conversation
    };

    var jsonPayload = JsonSerializer.Serialize(payload);
    using var content = new StringContent(jsonPayload, Encoding.UTF8, "application/json");
    var response = await client.PostAsync(endpoint, content);
    var body = await response.Content.ReadAsStringAsync();

    if (!response.IsSuccessStatusCode)
    {
        Console.WriteLine($"Error ({response.StatusCode}): {body}");
        return "";
    }

    using var doc = JsonDocument.Parse(body);
    var reply = doc.RootElement
                   .GetProperty("choices")[0]
                   .GetProperty("message")
                   .GetProperty("content")
                   .GetString();

    // Append the AI's response to the conversation history
    conversation.Add(new Message("assistant", reply?.Trim() ?? ""));

    return reply?.Trim() ?? "";
}

public class Program
{
    public static async Task Main(string[] args)
    {
        var apiKey = Environment.GetEnvironmentVariable("OPENAI_API_KEY");
        var baseUri = Environment.GetEnvironmentVariable("OPENAI_BASE_URL");
        if (string.IsNullOrEmpty(apiKey))
        {
            Console.WriteLine("Set your OPENAI_API_KEY.");
            return;
        }
        if (string.IsNullOrEmpty(baseUri))
        {
            Console.WriteLine("Set your OPENAI_BASE_URL (e.g. https://api.openai.com).");
            return;
        }

        var endpoint = baseUri.TrimEnd('/') + "/v1/chat/completions";

        // Start a session with an initial query
        var session = new List<Message>();

        // Get first response
        string reply = await SendMessage(endpoint, apiKey, session, "What was the most notable achievement of Albert Einstein?");
        Console.WriteLine("Answer: " + reply);

        // Add a follow-up query and get explanation with tutoring context
        string followUpReply = await SendMessage(endpoint, apiKey, session, "Can you provide three more examples?");
        Console.WriteLine("Follow-up: " + followUpReply);
    }
}

text

Answer: Albert Einstein's most notable achievement is generally considered to be his theory of relativity, particularly the general theory of relativity published in 1915...

text

Follow-up: Here are three more notable achievements of Albert Einstein:

1. Photoelectric Effect: In 1905, Einstein explained the photoelectric effect, demonstrating that light consists of particles called photons...

2. Einstein's Theory of Brownian Motion: Also in 1905, Einstein provided mathematical evidence for the existence of atoms...

3. Mass-Energy Equivalence: Einstein formulated the equation E=mc²...

// Iterate over the conversation history and print each message
foreach (var message in session)
{
    Console.WriteLine($"{Capitalize(message.role)}: {message.content}");
}

// Helper method to capitalize the first letter
private static string Capitalize(string input)
{
    if (string.IsNullOrEmpty(input)) return input;
    return char.ToUpper(input[0]) + input.Substring(1);
}

text

User: What was the most notable achievement of Albert Einstein?
Assistant: Albert Einstein's most notable achievement is generally considered to be his theory of relativity...
User: Can you provide three more examples?
Assistant: Here are three more notable achievements of Albert Einstein: 1. Photoelectric Effect... 2. Einstein's Theory of Brownian Motion... 3. Mass-Energy Equivalence...

Message Types and Session History

Understanding Message Types

Creating a Method to Handle Tutoring Sessions

Join the 1M+ learners on CodeSignal

Building and Managing Session History

Visualizing the Session History

Summary and Preparation for Practice