feat: added Amazon Bedrock Cohere R plus and Cohere R models (#285)

fix: fixed small issues

src/Providers/Amazon.Bedrock/src/Chat/CohereCommandRModel.cs

@@ -0,0 +1,105 @@
+using System.Diagnostics;
+using System.Text;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+using Amazon.BedrockRuntime.Model;
+using LangChain.Providers.Amazon.Bedrock.Internal;
+
+// ReSharper disable once CheckNamespace
+namespace LangChain.Providers.Amazon.Bedrock;
+
+public abstract class CohereCommandRModel(
+    BedrockProvider provider,
+    string id)
+    : ChatModel(id)
+{
+    /// <summary>
+    /// Generates a chat response based on the provided `ChatRequest`.
+    /// </summary>
+    /// <param name="request">The `ChatRequest` containing the input messages and other parameters.</param>
+    /// <param name="settings">Optional `ChatSettings` to override the model's default settings.</param>
+    /// <param name="cancellationToken">A cancellation token to cancel the operation.</param>
+    /// <returns>A `ChatResponse` containing the generated messages and usage information.</returns>
+    public override async Task<ChatResponse> GenerateAsync(
+        ChatRequest request,
+        ChatSettings? settings = null,
+        CancellationToken cancellationToken = default)
+    {
+        request = request ?? throw new ArgumentNullException(nameof(request));
+
+        var watch = Stopwatch.StartNew();
+        var prompt = request.Messages.ToSimplePrompt();
+        var messages = request.Messages.ToList();
+
+        var stringBuilder = new StringBuilder();
+
+        var usedSettings = CohereCommandChatSettings.Calculate(
+            requestSettings: settings,
+            modelSettings: Settings,
+            providerSettings: provider.ChatSettings);
+
+        var bodyJson = CreateBodyJson(prompt, usedSettings);
+
+        if (usedSettings.UseStreaming == true)
+        {
+            var streamRequest = BedrockModelRequest.CreateStreamRequest(Id, bodyJson);
+            var response = await provider.Api.InvokeModelWithResponseStreamAsync(streamRequest, cancellationToken).ConfigureAwait(false);
+
+            foreach (var payloadPart in response.Body)
+            {
+                var streamEvent = (PayloadPart)payloadPart;
+                var chunk = await JsonSerializer.DeserializeAsync<JsonObject>(streamEvent.Bytes, cancellationToken: cancellationToken)
+                    .ConfigureAwait(false);
+                var delta = chunk?["text"]?.GetValue<string>() ?? string.Empty;
+
+                OnPartialResponseGenerated(delta);
+                stringBuilder.Append(delta);
+
+                var finished = chunk?["finish_reason"]?.GetValue<string>() ?? string.Empty;
+                if (string.Equals(finished.ToUpperInvariant(), "COMPLETE", StringComparison.Ordinal))
+                {
+                    OnCompletedResponseGenerated(stringBuilder.ToString());
+                }
+            }
+        }
+        else
+        {
+            var response = await provider.Api.InvokeModelAsync(Id, bodyJson, cancellationToken)
+                .ConfigureAwait(false);
+
+            var generatedText = response?["text"]?.GetValue<string>() ?? string.Empty;
+
+            messages.Add(generatedText.AsAiMessage());
+            OnCompletedResponseGenerated(generatedText);
+        }
+
+        var usage = Usage.Empty with
+        {
+            Time = watch.Elapsed,
+        };
+        AddUsage(usage);
+        provider.AddUsage(usage);
+
+        return new ChatResponse
+        {
+            Messages = messages,
+            UsedSettings = usedSettings,
+            Usage = usage,
+        };
+    }
+
+    /// <summary>
+    /// Creates the request body JSON for the Cohere model based on the provided prompt and settings.
+    /// </summary>
+    /// <param name="prompt">The input prompt for the model.</param>
+    /// <param name="usedSettings">The settings to use for the request.</param>
+    /// <returns>A `JsonObject` representing the request body.</returns>
+    private static JsonObject CreateBodyJson(string prompt, CohereCommandChatSettings usedSettings)
+    {
+        var bodyJson = new JsonObject
+        {
+            ["message"] = prompt,
+        };
+        return bodyJson;
+    }
+}

src/Providers/Amazon.Bedrock/src/Chat/Settings/MetaLlama2ChatSettings.cs

@@ -9,7 +9,7 @@ public class MetaLlama2ChatSettings : BedrockChatSettings
         User = ChatSettings.Default.User,
         UseStreaming = false,
         Temperature = 0.5,
-        MaxTokens = 4000,
+        MaxTokens = 2048,
         TopP = 0.9,
         TopK = 0.0
     };

src/Providers/Amazon.Bedrock/src/Embedding/AmazonTitanEmbeddingV2Model.cs

@@ -0,0 +1,88 @@
+using System.Diagnostics;
+using System.Text.Json.Nodes;
+using LangChain.Providers.Amazon.Bedrock.Internal;
+
+// ReSharper disable once CheckNamespace
+namespace LangChain.Providers.Amazon.Bedrock;
+
+public abstract class AmazonTitanEmbeddingV2Model(
+    BedrockProvider provider,
+    string id)
+    : Model<EmbeddingSettings>(id), IEmbeddingModel
+{
+
+    /// <summary>
+    /// Creates embeddings for the input strings using the Amazon model.
+    /// </summary>
+    /// <param name="request">The `EmbeddingRequest` containing the input strings.</param>
+    /// <param name="settings">Optional `EmbeddingSettings` to override the model's default settings.</param>
+    /// <param name="cancellationToken">A cancellation token to cancel the operation.</param>
+    /// <returns>An `EmbeddingResponse` containing the generated embeddings and usage information.</returns>
+
+    public async Task<EmbeddingResponse> CreateEmbeddingsAsync(
+        EmbeddingRequest request,
+        EmbeddingSettings? settings = null,
+        CancellationToken cancellationToken = default)
+    {
+        request = request ?? throw new ArgumentNullException(nameof(request));
+
+        var watch = Stopwatch.StartNew();
+
+        var usedSettings = AmazonV2EmbeddingSettings.Calculate(
+            requestSettings: settings,
+            modelSettings: Settings,
+            providerSettings: provider.EmbeddingSettings);
+
+        var embeddings = new List<float[]>(capacity: request.Strings.Count);
+
+        var tasks = request.Strings.Select(text =>
+        {
+            var bodyJson = CreateBodyJson(text, usedSettings);
+            return provider.Api.InvokeModelAsync(Id, bodyJson,
+                cancellationToken);
+        })
+        .ToList();
+        var results = await Task.WhenAll(tasks).ConfigureAwait(false);
+
+        foreach (var response in results)
+        {
+            var embedding = response?["embedding"]?.AsArray();
+            if (embedding == null) continue;
+
+            var f = new float[(int)usedSettings.Dimensions!];
+            for (var i = 0; i < embedding.Count; i++)
+            {
+                f[i] = (float)embedding[(Index)i]?.AsValue()!;
+            }
+
+            embeddings.Add(f);
+        }
+
+        var usage = Usage.Empty with
+        {
+            Time = watch.Elapsed,
+        };
+        AddUsage(usage);
+        provider.AddUsage(usage);
+
+        return new EmbeddingResponse
+        {
+            Values = embeddings.ToArray(),
+            Usage = Usage.Empty,
+            UsedSettings = usedSettings,
+            Dimensions = embeddings.FirstOrDefault()?.Length ?? 0,
+        };
+    }
+
+    private static JsonObject CreateBodyJson(string? prompt, AmazonV2EmbeddingSettings usedSettings)
+    {
+        var bodyJson = new JsonObject
+        {
+            ["inputText"] = prompt,
+            ["dimensions"] = usedSettings.Dimensions,
+            ["normalize"] = usedSettings.Normalize
+        };
+
+        return bodyJson;
+    }
+}

src/Providers/Amazon.Bedrock/src/Embedding/Settings/AmazonV2EmbeddingSettings.cs

@@ -0,0 +1,55 @@
+// ReSharper disable once CheckNamespace
+namespace LangChain.Providers.Amazon.Bedrock;
+
+public class AmazonV2EmbeddingSettings : BedrockEmbeddingSettings
+{
+    public new static AmazonV2EmbeddingSettings Default { get; } = new()
+    {
+        Dimensions = 1024,
+        MaximumInputLength = 10_000,
+        Normalize = true
+    };
+
+    public bool Normalize { get; set; }
+
+    /// <summary>
+    /// Calculate the settings to use for the request.
+    /// </summary>
+    /// <param name="requestSettings"></param>
+    /// <param name="modelSettings"></param>
+    /// <param name="providerSettings"></param>
+    /// <returns></returns>
+    /// <exception cref="InvalidOperationException"></exception>
+    public new static AmazonV2EmbeddingSettings Calculate(
+        EmbeddingSettings? requestSettings,
+        EmbeddingSettings? modelSettings,
+        EmbeddingSettings? providerSettings)
+    {
+        var requestSettingsCasted = requestSettings as AmazonV2EmbeddingSettings;
+        var modelSettingsCasted = modelSettings as AmazonV2EmbeddingSettings;
+        var providerSettingsCasted = providerSettings as AmazonV2EmbeddingSettings;
+
+        return new AmazonV2EmbeddingSettings
+        {
+            Dimensions =
+                requestSettingsCasted?.Dimensions ??
+                modelSettingsCasted?.Dimensions ??
+                providerSettingsCasted?.Dimensions ??
+                Default.Dimensions ??
+                throw new InvalidOperationException("Default Dimensions is not set."),
+
+            MaximumInputLength =
+                requestSettingsCasted?.MaximumInputLength ??
+                modelSettingsCasted?.MaximumInputLength ??
+                providerSettingsCasted?.MaximumInputLength ??
+                Default.MaximumInputLength ??
+                throw new InvalidOperationException("Default MaximumInputLength is not set."),
+
+            Normalize =
+                requestSettingsCasted?.Normalize ??
+                modelSettingsCasted?.Normalize ??
+                providerSettingsCasted?.Normalize ??
+                Default.Normalize,
+        };
+    }
+}

src/Providers/Amazon.Bedrock/src/Predefined/Amazon.cs

@@ -13,6 +13,10 @@ public class TitanTextLiteV1Model(BedrockProvider provider)
 public class TitanEmbedTextV1Model(BedrockProvider provider)
     : AmazonTitanEmbeddingModel(provider, id: "amazon.titan-embed-text-v1");
 
+/// <inheritdoc />
+public class TitanEmbedTextV2Model(BedrockProvider provider)
+    : AmazonTitanEmbeddingV2Model(provider, id: "amazon.titan-embed-text-v2:0");
+
 /// <inheritdoc />
 public class TitanEmbedImageV1Model(BedrockProvider provider)
     : AmazonTitanImageEmbeddingModel(provider, id: "amazon.titan-embed-image-v1");

src/Providers/Amazon.Bedrock/src/Predefined/Cohere.cs

@@ -16,3 +16,11 @@ public class EmbedEnglishV3Model(BedrockProvider provider)
 /// <inheritdoc />
 public class EmbedMultilingualV3Model(BedrockProvider provider)
     : CohereEmbeddingModel(provider, id: "cohere.embed-multilingual-v3");
+
+/// <inheritdoc />
+public class CommandRPlusModel(BedrockProvider provider)
+    : CohereCommandRModel(provider, id: "cohere.command-r-plus-v1:0");
+
+/// <inheritdoc />
+public class CommandRModel(BedrockProvider provider)
+    : CohereCommandRModel(provider, id: "cohere.command-r-v1:0");

src/Providers/Amazon.Bedrock/src/Predefined/Mistral.cs

@@ -7,7 +7,7 @@ public class Mistral7BInstruct(BedrockProvider provider)
 
 /// <inheritdoc />
 public class Mistral8x7BInstruct(BedrockProvider provider)
-    : MistralModel(provider, id: "mistral.mistral-8x7b-instruct-v0:1");
+    : MistralModel(provider, id: "mistral.mixtral-8x7b-instruct-v0:1");
 
 /// <inheritdoc />
 public class MistralLarge(BedrockProvider provider)

src/Providers/Amazon.Bedrock/test/BedrockTests.cs

@@ -13,11 +13,11 @@
 using LangChain.Providers.Amazon.Bedrock.Predefined.Anthropic;
 using LangChain.Providers.Amazon.Bedrock.Predefined.Cohere;
 using LangChain.Providers.Amazon.Bedrock.Predefined.Meta;
+using LangChain.Providers.Amazon.Bedrock.Predefined.Mistral;
 using LangChain.Providers.Amazon.Bedrock.Predefined.Stability;
 using LangChain.Schema;
 using LangChain.Splitters.Text;
 using static LangChain.Chains.Chain;
-using Microsoft.SemanticKernel.AI.Embeddings;
 
 namespace LangChain.Providers.Amazon.Bedrock.Tests;
 
@@ -31,7 +31,7 @@ public async Task Chains()
         //var llm = new Jurassic2MidModel(provider);
         //var llm = new ClaudeV21Model(provider);
         //var llm = new Mistral7BInstruct(provider);
-        var llm = new Claude3SonnetModel(provider);
+        var llm = new CommandRModel(provider);
 
         var template = "What is a good name for a company that makes {product}?";
         var prompt = new PromptTemplate(new PromptTemplateInput(template, new List<string>(1) { "product" }));
@@ -271,7 +271,7 @@ public async Task ClaudeImageToText()
     public async Task SimpleTest(bool useStreaming, bool useChatSettings)
     {
         var provider = new BedrockProvider();
-        var llm = new CommandLightTextV14Model(provider);
+        var llm = new CommandRModel(provider);
 
         llm.PromptSent += (_, prompt) => Console.WriteLine($"Prompt: {prompt}");
         llm.PartialResponseGenerated += (_, delta) => Console.Write(delta);
@@ -290,6 +290,7 @@ you are a comic book writer.  you will be given a question and you will answer i
         {
             var response = await llm.GenerateAsync(prompt);
             response.LastMessageContent.Should().NotBeNull();
+            Console.WriteLine(response.LastMessageContent);
         }
     }
 

src/Providers/Amazon.Bedrock/test/BedrockTextModelTests.cs

@@ -1,6 +1,7 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.CSharp;
 using System.Reflection;
+using Amazon;
 
 namespace LangChain.Providers.Amazon.Bedrock.Tests;
 
@@ -20,7 +21,7 @@ public Task TestAllTextLLMs()
 
         var derivedTypeNames = FindDerivedTypes(predefinedDir);
 
-        var provider = new BedrockProvider();
+        var provider = new BedrockProvider(RegionEndpoint.USWest2);
 
         var failedTypes = new List<string>();
         var workingTypes = new Dictionary<string, double>();
@@ -44,13 +45,20 @@ public Task TestAllTextLLMs()
 
                 Console.WriteLine($"############## {type.FullName}");
 
-                object[] args = { provider };
+                object[] args = [provider];
                 var llm = (ChatModel)Activator.CreateInstance(type, args)!;
-                var result = llm.GenerateAsync("who's your favor superhero?");
+                try
+                {
+                    var result = llm.GenerateAsync("who's your favorite superhero?");
 
-                workingTypes.Add(className, result.Result.Usage.Time.TotalSeconds);
+                    workingTypes.Add(className, result.Result.Usage.Time.TotalSeconds);
 
-                Console.WriteLine(result.Result + "\n\n\n");
+                    Console.WriteLine(result.Result + "\n\n\n");
+                }
+                catch (Exception e)
+                {
+                    Console.WriteLine($"****        ****        **** ERROR: " + e);
+                }
             }
         }
         catch (Exception e)