Cohere: Add CohereClient and CohereChatModel to support Chat

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/CohereChatModel.java

@@ -0,0 +1,124 @@
+package dev.langchain4j.model.cohere;
+
+import dev.langchain4j.agent.tool.ToolSpecification;
+import dev.langchain4j.data.message.*;
+import dev.langchain4j.model.chat.ChatLanguageModel;
+import dev.langchain4j.model.cohere.internal.api.CohereChatRequest;
+import dev.langchain4j.model.cohere.internal.api.CohereChatResponse;
+import dev.langchain4j.model.cohere.internal.client.CohereClient;
+import dev.langchain4j.model.output.Response;
+import lombok.Builder;
+
+import java.time.Duration;
+import java.util.List;
+
+import static dev.langchain4j.internal.RetryUtils.withRetry;
+import static dev.langchain4j.internal.Utils.getOrDefault;
+import static dev.langchain4j.internal.ValidationUtils.ensureNotEmpty;
+import static dev.langchain4j.model.cohere.internal.mapper.CohereMapper.*;
+
+/**
+ * An implementation of a ChatModel that uses
+ * <a href="https://docs.cohere.com/docs/command-r">Cohere Command R API</a>.
+ */
+public class CohereChatModel implements ChatLanguageModel {
+
+    private static final String DEFAULT_BASE_URL = "https://api.cohere.ai/v1/";
+
+    private final CohereClient client;
+    private final String modelName;
+    private final Double temperature;
+    private final Double topP;
+    private final Integer topK;
+    private final Integer maxTokens;
+    private final List<String> stopSequences;
+    private final Integer maxRetries;
+
+    /**
+     * Constructs an instance of an {@code CohereChatModel} with the specified parameters.
+     *
+     * @param baseUrl       The base URL of the Cohere API. Default: "https://api.cohere.ai/v1/"
+     * @param apiKey        The API key for authentication with the Cohere API.
+     * @param modelName     The name of the Cohere model to use. Default: command-r
+     * @param temperature   The temperature. Default: 0.3
+     * @param topP          The top-P. Defaults to 0.75. min value of 0.01, max value of 0.99.
+     * @param topK          The top-K. Defaults to 0, min value of 0, max value of 500.
+     * @param maxTokens     The maximum number of tokens the model will generate as part of the response.
+     * @param stopSequences The custom text sequences that will cause the model to stop generating
+     * @param timeout       The timeout for API requests. Default: 60 seconds
+     * @param maxRetries    The maximum number of retries for API requests. Default: 3
+     * @param logRequests   Whether to log the content of API requests using SLF4J. Default: false
+     * @param logResponses  Whether to log the content of API responses using SLF4J. Default: false
+     */
+    @Builder
+    private CohereChatModel(String baseUrl,
+                            String apiKey,
+                            String modelName,
+                            Double temperature,
+                            Double topP,
+                            Integer topK,
+                            Integer maxTokens,
+                            List<String> stopSequences,
+                            Duration timeout,
+                            Integer maxRetries,
+                            Boolean logRequests,
+                            Boolean logResponses) {
+        this.client = CohereClient.builder()
+                .baseUrl(getOrDefault(baseUrl, DEFAULT_BASE_URL))
+                .apiKey(apiKey)
+                .timeout(getOrDefault(timeout, Duration.ofSeconds(60)))
+                .logRequests(getOrDefault(logRequests, false))
+                .logResponses(getOrDefault(logResponses, false))
+                .build();
+        this.modelName = getOrDefault(modelName, "command-r");
+        this.temperature = temperature;
+        this.topP = topP;
+        this.topK = topK;
+        this.maxTokens = getOrDefault(maxTokens, 1024);
+        this.stopSequences = stopSequences;
+        this.maxRetries = getOrDefault(maxRetries, 3);
+    }
+
+    /**
+     * Creates an instance of {@code CohereChatModel} with the specified API key.
+     *
+     * @param apiKey the API key for authentication
+     * @return an {@code CohereChatModel} instance
+     */
+    public static CohereChatModel withApiKey(String apiKey) {
+        return builder().apiKey(apiKey).build();
+    }
+
+    @Override
+    public Response<AiMessage> generate(List<ChatMessage> messages) {
+        return generate(messages, (List<ToolSpecification>) null);
+    }
+
+    @Override
+    public Response<AiMessage> generate(List<ChatMessage> messages, List<ToolSpecification> tools) {
+        ensureNotEmpty(messages, "messages");
+
+        CohereChatRequest request = CohereChatRequest.builder()
+                .model(modelName)
+                .preamble(toPreamble(messages))
+                .message(toCohereMessage(messages.get(messages.size() - 1)))
+                .toolResults(toToolResults(messages))
+                .chatHistory(toChatHistory(messages.subList(0, messages.size() - 1)))
+                .maxTokens(maxTokens)
+                .stopSequences(stopSequences)
+                .stream(false)
+                .temperature(temperature)
+                .p(topP)
+                .k(topK)
+                .tools(toCohereTools(tools))
+                .build();
+
+        CohereChatResponse response = withRetry(() -> client.chat(request), maxRetries);
+
+        return Response.from(
+                toAiMessage(response),
+                toTokenUsage(response.getMeta().getBilledUnits())
+        );
+    }
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/CohereScoringModel.java

@@ -1,6 +1,10 @@
 package dev.langchain4j.model.cohere;
 
 import dev.langchain4j.data.segment.TextSegment;
+import dev.langchain4j.model.cohere.internal.api.RerankRequest;
+import dev.langchain4j.model.cohere.internal.api.RerankResponse;
+import dev.langchain4j.model.cohere.internal.api.Result;
+import dev.langchain4j.model.cohere.internal.client.CohereClient;
 import dev.langchain4j.model.output.Response;
 import dev.langchain4j.model.output.TokenUsage;
 import dev.langchain4j.model.scoring.ScoringModel;

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/internal/api/BilledUnits.java

@@ -0,0 +1,15 @@
+package dev.langchain4j.model.cohere.internal.api;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+@Getter
+@AllArgsConstructor
+public class BilledUnits {
+
+    private Integer searchUnits;
+
+    private Integer inputTokens;
+
+    private Integer outputTokens;
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/internal/api/ChatHistory.java

@@ -0,0 +1,15 @@
+package dev.langchain4j.model.cohere.internal.api;
+
+import lombok.Builder;
+import lombok.NonNull;
+
+@Builder
+public class ChatHistory {
+
+    @NonNull
+    CohereRole role;
+
+    @NonNull
+    String message;
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/internal/api/Citation.java

@@ -0,0 +1,19 @@
+package dev.langchain4j.model.cohere.internal.api;
+
+import lombok.Getter;
+import lombok.ToString;
+
+import java.util.List;
+
+
+@Getter
+@ToString
+public class Citation {
+    Integer start;
+
+    Integer end;
+
+    String text;
+
+    List<String> documentIds;
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/CohereApi.java → langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/internal/api/CohereApi.java

@@ -1,12 +1,16 @@
-package dev.langchain4j.model.cohere;
+package dev.langchain4j.model.cohere.internal.api;
 
 import retrofit2.Call;
 import retrofit2.http.Body;
 import retrofit2.http.Header;
 import retrofit2.http.Headers;
 import retrofit2.http.POST;
 
-interface CohereApi {
+public interface CohereApi {
+
+    @POST("chat")
+    @Headers({"Content-Type: application/json"})
+    Call<CohereChatResponse> chat(@Body CohereChatRequest request, @Header("Authorization") String authorizationHeader);
 
     @POST("rerank")
     @Headers({"Content-Type: application/json"})

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/internal/api/CohereChatRequest.java

@@ -0,0 +1,53 @@
+package dev.langchain4j.model.cohere.internal.api;
+
+import lombok.Builder;
+import lombok.NonNull;
+
+import java.util.List;
+import java.util.Map;
+
+@Builder
+public class CohereChatRequest {
+
+    @NonNull
+    String message;
+
+    String model;
+
+    Boolean stream;
+
+    String preamble;
+
+    List<ChatHistory> chatHistory;
+
+    String conversationId;
+
+    String promptTruncation;
+
+    List<Connector> connectors;
+
+    Boolean searchQueriesOnly;
+
+    List<Map<String, String>> documents;
+
+    Double temperature;
+
+    Integer maxTokens;
+
+    Integer k;
+
+    Double p;
+
+    Double seed;
+
+    List<String> stopSequences;
+
+    Double frequencyPenalty;
+
+    Double presencePenalty;
+
+    List<Tool> tools;
+
+    List<ToolResult> toolResults;
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/internal/api/CohereChatResponse.java

@@ -0,0 +1,34 @@
+package dev.langchain4j.model.cohere.internal.api;
+
+import lombok.Getter;
+
+import java.util.List;
+import java.util.Map;
+
+
+@Getter
+public class CohereChatResponse {
+
+    String text;
+
+    String generationId;
+
+    List<Citation> citations;
+
+    List<Map<String, String>> documents;
+
+    Boolean isSearchRequired;
+
+    List<SearchQuery> searchQueries;
+
+    List<SearchResult> searchResults;
+
+    String finishReason;
+
+    List<ToolCall> toolCalls;
+
+    List<ChatHistory> chatHistory;
+
+    Meta meta;
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/internal/api/CohereRole.java

@@ -0,0 +1,11 @@
+package dev.langchain4j.model.cohere.internal.api;
+
+public enum CohereRole {
+
+    CHATBOX,
+
+    SYSTEM,
+
+    USER
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/internal/api/Connector.java

@@ -0,0 +1,20 @@
+package dev.langchain4j.model.cohere.internal.api;
+
+import lombok.Builder;
+import lombok.NonNull;
+
+import java.util.Map;
+
+@Builder
+public class Connector {
+
+    @NonNull
+    String id;
+
+    String userAccessToken;
+
+    Boolean continueOnFailure;
+
+    Map<String, String> options;
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/Meta.java → langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/internal/api/Meta.java

@@ -1,9 +1,10 @@
-package dev.langchain4j.model.cohere;
+package dev.langchain4j.model.cohere.internal.api;
 
 import lombok.Getter;
 
+
 @Getter
-class Meta {
+public class Meta {
 
     private BilledUnits billedUnits;
 }

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/internal/api/ParameterDefinition.java

@@ -0,0 +1,15 @@
+package dev.langchain4j.model.cohere.internal.api;
+
+import lombok.Builder;
+import lombok.NonNull;
+
+@Builder
+public class ParameterDefinition {
+
+    String description;
+
+    @NonNull
+    String type;
+
+    Boolean required;
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/RerankRequest.java → langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/internal/api/RerankRequest.java

@@ -1,11 +1,10 @@
-package dev.langchain4j.model.cohere;
+package dev.langchain4j.model.cohere.internal.api;
 
 import lombok.Builder;
 
 import java.util.List;
-
 @Builder
-class RerankRequest {
+public class RerankRequest {
 
     private String model;
     private String query;

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/RerankResponse.java → langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/internal/api/RerankResponse.java

@@ -1,11 +1,13 @@
-package dev.langchain4j.model.cohere;
+package dev.langchain4j.model.cohere.internal.api;
+
 
 import lombok.Getter;
 
 import java.util.List;
 
+
 @Getter
-class RerankResponse {
+public class RerankResponse {
 
     private List<Result> results;
     private Meta meta;