Mistral.SDK

Mistral.SDK is an unofficial C# client designed for interacting with the Mistral API. This powerful interface simplifies the integration of Mistral AI into your C# applications. It targets netstandard2.0, .net6.0 and .net8.0.

Table of Contents

• Installation
• API Keys
• HttpClient
• Usage
• Examples
  • Non-Streaming Call
  • Streaming Call
  • IChatClient
  • List Models
  • Embeddings
  • Function Calling
• Contributing
• License

Installation

Install Mistral.SDK via the NuGet package manager:

PM> Install-Package Mistral.SDK

API Keys

You can load the API Key from an environment variable named MISTRAL_API_KEY by default. Alternatively, you can supply it as a string to the MistralClient constructor.

HttpClient

The MistralClient can optionally take a custom HttpClient in the MistralClient constructor, which allows you to control elements such as retries and timeouts. Note: If you provide your own HttpClient, you are responsible for disposal of that client.

Usage

There are three ways to start using the MistralClient. The first is to simply new up an instance of the MistralClient and start using it, the second is to use the messaging/Embedding client with the new Microsoft.Extensions.AI.Abstractions builder. The third is to use the Completions client with Microsoft.SemanticKernel. Brief examples of each are below.

Option 1:

var client = new MistralClient();

Option 2:

//chat client
IChatClient client = new MistralClient().Completions;

//embeddings generator
IEmbeddingGenerator<string, Embedding<float>> client = new MistralClient().Embeddings;

Option 3:

using Microsoft.SemanticKernel;

var skChatService =
    new ChatClientBuilder(new MistralClient().Completions)
        .UseFunctionInvocation()
        .Build()
        .AsChatCompletionService();


var sk = Kernel.CreateBuilder();
sk.Plugins.AddFromType<SkPlugins>("Weather");
sk.Services.AddSingleton<IChatCompletionService>(skChatService);

See integration tests for a more complete example.

All support all the core features of the MistralClient's Messaging and Embedding capabilities, but the latter will be fully featured in .NET 9 and provide built in telemetry and DI and make it easier to choose which SDK you are using.

Examples

Non-Streaming Call

Here's an example of a non-streaming call to the mistral-medium completions endpoint (other options are available and documented, but omitted for brevity):

var client = new MistralClient();
var request = new ChatCompletionRequest(
    //define model - required
    ModelDefinitions.MistralMedium,
    //define messages - required
    new List<ChatMessage>()
{
    new ChatMessage(ChatMessage.RoleEnum.System, 
        "You are an expert at writing sonnets."),
    new ChatMessage(ChatMessage.RoleEnum.User, 
        "Write me a sonnet about the Statue of Liberty.")
}, 
    //optional - defaults to false
    safePrompt: true, 
    //optional - defaults to 0.7
    temperature: 0, 
    //optional - defaults to null
    maxTokens: 500, 
    //optional - defaults to 1
    topP: 1, 
    //optional - defaults to null
    randomSeed: 32);
var response = await client.Completions.GetCompletionAsync(request);
Console.WriteLine(response.Choices.First().Message.Content);

Streaming Call

The following is an example of a streaming call to the mistral-medium completions endpoint:

var client = new MistralClient();
var request = new ChatCompletionRequest(
    ModelDefinitions.MistralMedium, 
    new List<ChatMessage>()
{
    new ChatMessage(ChatMessage.RoleEnum.System, 
        "You are an expert at writing sonnets."),
    new ChatMessage(ChatMessage.RoleEnum.User, 
        "Write me a sonnet about the Statue of Liberty.")
});
var results = new List<ChatCompletionResponse>();
await foreach (var res in client.Completions.StreamCompletionAsync(request))
{
    results.Add(res);
    Console.Write(res.Choices.First().Delta.Content);
}

IChatClient

The MistralClient has support for the new IChatClient from Microsoft and offers a slightly different mechanism for using the MistralClient. Below are a few examples.

//non-streaming
IChatClient client = new MistralClient().Completions;

var response = await client.GetResponseAsync(new List<ChatMessage>()
{
    new(ChatRole.System, "You are an expert at writing sonnets."),
    new(ChatRole.User, "Write me a sonnet about the Statue of Liberty.")
}, new() { ModelId = ModelDefinitions.OpenMistral7b });

Assert.IsTrue(!string.IsNullOrEmpty(response.Message.Text));

//streaming call
IChatClient client = new MistralClient().Completions;

var sb = new StringBuilder();
await foreach (var update in client.GetStreamingResponseAsync(new List<ChatMessage>()
    {
        new(ChatRole.System, "You are an expert at writing Json."),
        new(ChatRole.User, "Write me a simple 'hello world' statement in a json object with a single 'result' key.")
    }, new() { ModelId = ModelDefinitions.MistralLarge, ResponseFormat = ChatResponseFormat.Json }))
{
    sb.Append(update);
}

//parse json
Assert.IsNotNull(JsonSerializer.Deserialize<JsonResult>(sb.ToString()));

//Embeddings call
IEmbeddingGenerator<string, Embedding<float>> = new MistralClient().Embeddings;
            var response = await client.GenerateVectorAsync("hello world", new() { ModelId = ModelDefinitions.MistralEmbed });
            Assert.IsTrue(!response.IsEmpty);

//Functions call
IChatClient client = new MistralClient().Completions
    .AsBuilder()
    .UseFunctionInvocation()
    .Build();

ChatOptions options = new()
{
    ModelId = ModelDefinitions.MistralSmall,
    MaxOutputTokens = 512,
    ToolMode = ChatToolMode.Auto,
    Tools = [AIFunctionFactory.Create((string personName) => personName switch {
        "Alice" => "25",
        _ => "40"
    }, "GetPersonAge", "Gets the age of the person whose name is specified.")]
};

var res = await client.GetResponseAsync("How old is Alice?", options);

Assert.IsTrue(
    res.Message.Text?.Contains("25") is true,
    res.Message.Text);

Please see the integration tests for even more examples.

List Models

The following is an example of a call to list the available models:

var client = new MistralClient();

var response = await client.Models.GetModelsAsync();

Embeddings

The following is an example of a call to the mistral-embed embeddings model/endpoint:

var client = new MistralClient();
var request = new EmbeddingRequest(
    ModelDefinitions.MistralEmbed, 
    new List<string>() { "Hello world" }, 
    EmbeddingRequest.EncodingFormatEnum.Float);
var response = await client.Embeddings.GetEmbeddingsAsync(request);

Function Calling

The MistralClient supports Function Calling through a variety of mechanisms. It's worth noting that currently some models seem to hallucinate function calling behavior more than others, and this is a known issue with Mistral.

public enum TempType
{
    Fahrenheit,
    Celsius
}

[Function("This function returns the weather for a given location")]
public static async Task<string> GetWeather([FunctionParameter("Location of the weather", true)] string location,
    [FunctionParameter("Unit of temperature, celsius or fahrenheit", true)] TempType tempType)
{
    await Task.Yield();
    return "72 degrees and sunny";
}

//declared globally
var client = new MistralClient();
var messages = new List<ChatMessage>()
{
    new ChatMessage(ChatMessage.RoleEnum.User, "What is the weather in San Francisco, CA in Fahrenheit?")
};
var request = new ChatCompletionRequest(ModelDefinitions.MistralSmall, messages);
request.MaxTokens = 1024;
request.Temperature = 0.0m;
request.ToolChoice = ToolChoiceType.Auto;

request.Tools = Common.Tool.GetAllAvailableTools(includeDefaults: false, forceUpdate: true, clearCache: true).ToList();

var response = await client.Completions.GetCompletionAsync(request).ConfigureAwait(false);

messages.Add(response.Choices.First().Message);

foreach (var toolCall in response.ToolCalls)
{
    var resp = await toolCall.InvokeAsync<string>();
    messages.Add(new ChatMessage(toolCall, resp));
}

var finalResult = await client.Completions.GetCompletionAsync(request).ConfigureAwait(false);

Assert.IsTrue(finalResult.Choices.First().Message.Content.Contains("72"));

//from a func
var client = new MistralClient();
var messages = new List<ChatMessage>()
{
    new ChatMessage(ChatMessage.RoleEnum.User,"How many characters are in the word Christmas, multiply by 5, add 6, subtract 2, then divide by 2.1?")
};
var request = new ChatCompletionRequest(ModelDefinitions.MistralSmall, messages);

request.ToolChoice = ToolChoiceType.Auto;

request.Tools = new List<Common.Tool>
{
    Common.Tool.FromFunc("ChristmasMathFunction",
        ([FunctionParameter("word to start with", true)]string word,
            [FunctionParameter("number to multiply word count by", true)]int multiplier,
            [FunctionParameter("amount to add to word count", true)]int addition,
            [FunctionParameter("amount to subtract from word count", true)]int subtraction,
            [FunctionParameter("amount to divide word count by", true)]double divisor) =>
        {
            return ((word.Length * multiplier + addition - subtraction) / divisor).ToString(CultureInfo.InvariantCulture);
        }, "Function that can be used to determine the number of characters