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Google Vertex AI PaLM 2

Get started​

To get started follow the steps outlined in the Get started section of Vertex AI Gemini integration tutorial to create a Google Cloud Platform account and establish a new project with access to Vertex AI API.

Add dependencies​

Add the following dependencies to your project's pom.xml:

<dependency>
  <groupId>dev.langchain4j</groupId>
  <artifactId>langchain4j-vertex-ai</artifactId>
  <version>0.36.2</version>
</dependency>

or project's build.gradle:

implementation 'dev.langchain4j:langchain4j-vertex-ai:0.36.2'

Try out an example code:​

An example of using Vertex AI Embedding Model

The PROJECT_ID field represents the variable you set when creating a new Google Cloud project.

import dev.langchain4j.data.message.AiMessage;
import dev.langchain4j.data.message.UserMessage;
import dev.langchain4j.model.chat.ChatLanguageModel;
import dev.langchain4j.model.output.Response;
import dev.langchain4j.model.vertexai.VertexAiChatModel;

public class ChatLanguageModel {

    private static final String PROJECT_ID = "YOUR-PROJECT-ID";
    // `chat-bison` means PaLM2 general purpose chat model
    private static final String MODEL_NAME = "chat-bison";

    public static void main(String[] args) {
        ChatLanguageModel model = VertexAiChatModel.builder()
            .endpoint("us-central1-aiplatform.googleapis.com:443")
            .location("us-central1")
            .publisher("google")
            .project(PROJECT_ID)
            .modelName(MODEL_NAME)
            .temperature(0.0)
            .build();

        Response<AiMessage> response = model.generate(
            UserMessage.from(
                "Describe in several sentences what language model you are: \n" +
                "Describe in several sentences what is your code name: "
            )
        );
        System.out.println(response.content().text());

        // I am a large language model, trained by Google. 
        // I am a transformer-based language model that has been trained 
        //     on a massive dataset of text and code. 
        // I am able to understand and generate human language, 
        //     and I can also write code in a variety of programming languages.
        //
        // My code name is PaLM 2, which stands for Pathways Language Model 2.

    }

}

Available chat models​

Chat models are optimized for multi-turn chat, where the model keeps track of previous messages in the chat and uses it as context for generating new responses.

Model nameDescriptionProperties
chat-bisonFine-tuned for multi-turn conversation use cases.Maximum input tokens: 8192. Maximum output tokens: 2048
chat-bison-32kFine-tuned for multi-turn conversation use cases.Max tokens (input + output): 32,768. Max output tokens: 8,192
codechat-bisonA model fine-tuned for chatbot conversations that help with code-related questions.Maximum input tokens: 6144. Maximum output tokens: 1024
codechat-bison-32kA model fine-tuned for chatbot conversations that help with code-related questions.Max tokens (input + output): 32,768. Max output tokens: 8,192

You can use bare model name e.g. chat-bison or specify a stable version, like chat-bison@002.

Available text models​

Text models are optimized for performing natural language tasks, such as classification, summarization, extraction, content creation, and ideation.

Use the VertexAiLanguageModel class for text models such as text-bison, text-bison-32k, and text-unicorn.

Reference​

Google Codelab on Vertex AI PaLM 2 Model

PaLM2 generation models

Model naming explanation

Available PalM stable versions

Examples​