Junaid.GoogleGemini.Net 4.0.0

Junaid.GoogleGemini.Net

An open-source .NET library to use Gemini API based on Google�s largest and most capable AI model yet.

Installation of Nuget Package

.NET CLI:

> dotnet add package Junaid.GoogleGemini.Net

Package Manager:

PM > Install-Package Junaid.GoogleGemini.Net

Authentication

Get an API key from Google's AI Studio here.

Add the API key to appsettings.json like this:

  "Gemini": {
    "Credentials": {
      "ApiKey": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
    }
  }

Or pass the API key as an environment variable named "GeminiApiKey".

Configuration

Configure the GeminiHttpClientOptions first.

builder.Services.Configure<GeminiHttpClientOptions>(builder.Configuration.GetSection("Gemini"));

Then call AddGemini extension method which configures a typed http client named GeminiClient and library services.

builder.Services.AddGemini();

Services

There are five services:

1. TextService
2. VisionService
3. ChatService
4. ModelInfoService
5. EmbeddingService

Each service has an interface. Obtain service instances by using their interfaces from the DI container.

The first three services from the above list contain the GenereateContentAsync method to generate text-only content, the StreamGenereateContentAsync method to provide a stream of text-only output and the CountTokensAsync method to count tokens.

• GenereateContentAsync is used to generate content in textual form. The input parameters to this method vary from service to service, however, an optional input parameter named configuration of type GenerateContentConfiguration is common among all services. For information on its usage navigate to the configuration section of this page.

  The GenereateContentAsync method returns the GenerateContentResponse object. To just get the text string inside this object, use the method Text() as shown in the code snippets given below.

• The StreamGenereateContentAsync takes the same parameters as GenereateContentAsync in their respective service, with an additional delegate Action<string>.

• The CountTokensAsync method takes the same parameters as GenereateContentAsync in their respective service. It does not take the optional configuration parameter.

The following sections show example code snippets that highlight how to use these services.

1. TextService

TextService is used to generate content with text-only input. It has three methods.

1. The GenereateContentAsync method takes a mandatory string (text prompt) as input, an optional GenerateContentConfiguration (model parameters and safety settings) argument and returns the GenerateContentResponse response object.

   app.MapGet("/", async (ITextService service) =>
   {
       var result = await service.GenereateContentAsync("Say hello to me.");
       return result.Text();
   });
   

2. The StreamGenereateContentAsync method is used to generate the stream of text-only content.

   ......
   Action<string> handleStreamData = (data) =>
   {
       Console.WriteLine(data);
   };
   await service.StreamGenereateContentAsync("Write a story on Google AI.", handleStreamData);
   

3. The CountTokensAsync method is used to get the total tokens count. When using long prompts, it might be useful to count tokens before sending any content to the model.

   ......
   var result = await service.CountTokensAsync("Write a story on Google AI.");
   Console.WriteLine(result.totalTokens);
   

2. VisionService

VisionService is used to generate content with both text and image inputs. It has three methods.

1. The GenereateContentAsync method takes mandatory string (text prompt) and FileObject (file bytes and file name), an optional GenerateContentConfiguration (model parameters and safety settings) argument and returns the GenerateContentResponse response object.

   string filePath = "path/<imageName.imageExtension>";
   var fileName = Path.GetFileName(filePath);
   byte[] fileBytes = Array.Empty<byte>();
   try
   {
       using (var imageStream = new FileStream(filePath, FileMode.Open, FileAccess.Read))
       using (var memoryStream = new MemoryStream())
       {
           imageStream.CopyTo(memoryStream);
           fileBytes = memoryStream.ToArray();
       }
       Console.WriteLine($"Image loaded successfully. Byte array length: {fileBytes.Length}");
   }
   catch (Exception ex)
   {
       Console.WriteLine($"Error: {ex.Message}");
   }
   
   var service = serviceProvider.GetService<IVisionService>();
   var result = await service.GenereateContentAsync("Explain this image?", new FileObject(fileBytes, fileName));
   Console.WriteLine(result.Text());
   

2. The StreamGenereateContentAsync method is used to generate the stream of text-only content.

   ......
   Action<string> handleStreamData = (data) =>
   {
       Console.WriteLine(data);
   };
   await service.StreamGenereateContentAsync("Explain this image?", new FileObject(fileBytes, fileName), handleStreamData);
   

3. The CountTokensAsync method is used to get the total tokens count. When using long prompts, it might be useful to count tokens before sending any content to the model.

   ......
   var result = await service.CountTokensAsync("Explain this image?", new FileObject(fileBytes, fileName));
   Console.WriteLine(result.totalTokens);
   

3. ChatService

ChatService is used to generate freeform conversations across multiple turns with chat history as input. It has three methods.

1. The GenereateContentAsync method takes an array of MessageObject as an argument, an optional GenerateContentConfiguration (model parameters and safety settings) argument and returns the GenerateContentResponse response object.

   Each MessageObject contains two fields i.e. a string named role (value can be either of "model" or "user" only) and another string named text (text prompt).

   var chat = new MessageObject[]
   {
       new MessageObject( "user", "Write the first line of a story about a magic backpack." ),
       new MessageObject( "model", "In the bustling city of Meadow brook, lived a young girl named Sophie. She was a bright and curious soul with an imaginative mind." ),
       new MessageObject( "user", "Write one more line." ),
   };
   
   var service = serviceProvider.GetService<IChatService>();
   var result = await service.GenereateContentAsync(chat);
   Console.WriteLine(result.Text());
   

2. The StreamGenereateContentAsync method is used to generate the stream of text-only content.

   ......
   Action<string> handleStreamData = (data) =>
   {
       Console.WriteLine(data);
   };
   await service.StreamGenereateContentAsync(chat, handleStreamData);
   

3. The CountTokensAsync method is used to get the total tokens count. When using long prompts, it might be useful to count tokens before sending any content to the model.

   ......
   var result = await service.CountTokensAsync(chat);
   Console.WriteLine(result.totalTokens);
   

Configuration

Configuration input can be used to control the content generation by configuring model parameters and by using safety settings.

An example of setting the configuration parameter of type GenerateContentConfiguration and passing it to the GenereateContentAsync method of TextService is as follows:

var configuration = new GenerateContentConfiguration
{
    safetySettings = new []
    {
        new SafetySetting
        {
            category = CategoryConstants.DangerousContent,
            threshold = ThresholdConstants.BlockOnlyHigh
        }
    },
    generationConfig = new GenerationConfig
    {
        stopSequences = new List<string> { "Title" },
        temperature = 1.0,
        maxOutputTokens = 800,
        topP = 0.8,
        topK = 10
    }
};

var result = await service.GenereateContentAsync("Write a quote by Aristotle.", configuration);
Console.WriteLine(result.Text());

4. ModelInfoService

ModelInfoService is used to return information about the model being used to generate content. It has two methods.

1. The ListModelsAsync method lists all of the models available through the API, including both the Gemini and PaLM family models.

   app.MapGet("/", async (IModelInfoService service) =>
   {
       var result = await service.ListModelsAsync();
   });
   

2. The GetModelAsync takes string (model name) as input and returns information about that model such as version, display name, input token limit, etc.

   ......
   var result = await service.GetModelAsync("gemini-pro-vision");
   

5. EmbeddingService

EmbeddingService is used to represent information as a list of floating point numbers in an array. It has two methods.

1. EmbedContentAsync takes a string (model name) and another string (text prompt) as arguments. It returns the EmbedContentResponse object.

   app.MapGet("/", async (IEmbeddingService service) =>
   {
       var result = await service.EmbedContentAsync("embedding-001", "Write a story about a magic backpack.");
   });
   

2. BatchEmbedContentAsync takes a string (model name) and a string[] (array of text prompts) as arguments. It returns the BatchEmbedContentResponse object.

   ......
   var result = await service.BatchEmbedContentAsync("embedding-001", new[] { "Write a story about a magic backpack.", "Say Hi to me!" });
   

GeminiClient

GeminiClient is a "Typed HttpClient". A case may arise where a custom GeminiClient is needed.

For example: Using proxy

In such a scenario, a custom HttpClient object will be used to set proxy parameters. This object will then be used to initialize the GeminiClient. To do so, several steps need to be performed:

1. Created a new Typed HttpClient

   public class CustomClient : GeminiClient
   {
       public CustomClient(HttpClient httpClient) : base(httpClient)
       {
       }
   }
   

2. Add relevant configuration to the Typed HttpClient and register it with the DI container.

   builder.Services.AddHttpClient<GeminiClient, CustomClient>((sp, client) =>
   {
       var options = sp.GetRequiredService<IOptions<GeminiHttpClientOptions>>().Value;
       client.BaseAddress = options.Url;
   })
   .ConfigurePrimaryHttpMessageHandler(() =>
   {
       var proxy = new WebProxy
       {
           Address = new Uri("http://localhost:1080/")
       };
   
       var httpClientHandler = new HttpClientHandler { Proxy = proxy, UseProxy = true };
   
       //Not recommended for production
       httpClientHandler.ServerCertificateCustomValidationCallback = HttpClientHandler.DangerousAcceptAnyServerCertificateValidator;
   
       return httpClientHandler;
   })
   .AddHttpMessageHandler<GeminiAuthHandler<GeminiHttpClientOptions>>();
   

3. Register the required service:

   builder.Services.AddTransient<ITextService, TextService>();
   

Thanks for using this library.

• Library needs improvements and the contributions are highly welcomed. Please read the contributing guidelines.

• The API is being manually released on Nuget.org. The release notes file lists down the release notes.

• Feel free to contact me via email if you have any questions or suggestions.