Test chat prompts (Generative AI)

Test a text prompt using a publisher chat model.

Code sample

Java

Before trying this sample, follow the Java setup instructions in the Vertex AI quickstart using client libraries. For more information, see the Vertex AI Java API reference documentation.

To authenticate to Vertex AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import com.google.cloud.aiplatform.v1beta1.EndpointName;
import com.google.cloud.aiplatform.v1beta1.PredictResponse;
import com.google.cloud.aiplatform.v1beta1.PredictionServiceClient;
import com.google.cloud.aiplatform.v1beta1.PredictionServiceSettings;
import com.google.protobuf.Value;
import com.google.protobuf.util.JsonFormat;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

// Send a Predict request to a large language model to test a chat prompt
public class PredictChatPromptSample {

  public static void main(String[] args) throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String instance =
        "{\n"
            + "   \"context\":  \"My name is Ned. You are my personal assistant. My favorite movies"
            + " are Lord of the Rings and Hobbit.\",\n"
            + "   \"examples\": [ { \n"
            + "       \"input\": {\"content\": \"Who do you work for?\"},\n"
            + "       \"output\": {\"content\": \"I work for Ned.\"}\n"
            + "    },\n"
            + "    { \n"
            + "       \"input\": {\"content\": \"What do I like?\"},\n"
            + "       \"output\": {\"content\": \"Ned likes watching movies.\"}\n"
            + "    }],\n"
            + "   \"messages\": [\n"
            + "    { \n"
            + "       \"author\": \"user\",\n"
            + "       \"content\": \"Are my favorite movies based on a book series?\"\n"
            + "    }]\n"
            + "}";
    String parameters =
        "{\n"
            + "  \"temperature\": 0.3,\n"
            + "  \"maxDecodeSteps\": 200,\n"
            + "  \"topP\": 0.8,\n"
            + "  \"topK\": 40\n"
            + "}";
    String project = "YOUR_PROJECT_ID";
    String publisher = "google";
    String model = "chat-bison@001";

    predictChatPrompt(instance, parameters, project, publisher, model);
  }

  static void predictChatPrompt(
      String instance, String parameters, String project, String publisher, String model)
      throws IOException {
    PredictionServiceSettings predictionServiceSettings =
        PredictionServiceSettings.newBuilder()
            .setEndpoint("us-central1-aiplatform.googleapis.com:443")
            .build();

    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests.
    try (PredictionServiceClient predictionServiceClient =
        PredictionServiceClient.create(predictionServiceSettings)) {
      String location = "us-central1";
      final EndpointName endpointName =
          EndpointName.ofProjectLocationPublisherModelName(project, location, publisher, model);

      Value.Builder instanceValue = Value.newBuilder();
      JsonFormat.parser().merge(instance, instanceValue);
      List<Value> instances = new ArrayList<>();
      instances.add(instanceValue.build());

      Value.Builder parameterValueBuilder = Value.newBuilder();
      JsonFormat.parser().merge(parameters, parameterValueBuilder);
      Value parameterValue = parameterValueBuilder.build();

      PredictResponse predictResponse =
          predictionServiceClient.predict(endpointName, instances, parameterValue);
      System.out.println("Predict Response");
    }
  }
}

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