Batch text prediction with Gemini model using Google Cloud Storage

Perform batch text prediction using Gemini model and returns the output location.

Explore further

For detailed documentation that includes this code sample, see the following:

• Batch inference from Cloud Storage
• Get batch predictions for Gemini

Code sample

Go

Before trying this sample, follow the Go setup instructions in the Vertex AI quickstart using client libraries. For more information, see the Vertex AI Go 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 (
	"context"
	"fmt"
	"io"
	"time"

	"google.golang.org/genai"
)

// generateBatchPredict runs a batch prediction job using GCS input/output.
func generateBatchPredict(w io.Writer, outputURI string) error {
	// outputURI = "gs://your-bucket/your-prefix"
	ctx := context.Background()

	client, err := genai.NewClient(ctx, &genai.ClientConfig{
		HTTPOptions: genai.HTTPOptions{APIVersion: "v1"},
	})
	if err != nil {
		return fmt.Errorf("failed to create genai client: %w", err)
	}

	// Source file with prompts for prediction
	src := &genai.BatchJobSource{
		Format: "jsonl",
		// Source link: https://storage.cloud.google.com/cloud-samples-data/batch/prompt_for_batch_gemini_predict.jsonl
		GCSURI: []string{"gs://cloud-samples-data/batch/prompt_for_batch_gemini_predict.jsonl"},
	}

	// Batch job config with output GCS location
	config := &genai.CreateBatchJobConfig{
		Dest: &genai.BatchJobDestination{
			Format: "jsonl",
			GCSURI: outputURI,
		},
	}
	// To use a tuned model, set the model param to your tuned model using the following format:
	//  modelName:= "projects/{PROJECT_ID}/locations/{LOCATION}/models/{MODEL_ID}
	modelName := "gemini-2.5-flash"
	// See the documentation: https://pkg.go.dev/google.golang.org/genai#Batches.Create
	job, err := client.Batches.Create(ctx, modelName, src, config)
	if err != nil {
		return fmt.Errorf("failed to create batch job: %w", err)
	}

	fmt.Fprintf(w, "Job name: %s\n", job.Name)
	fmt.Fprintf(w, "Job state: %s\n", job.State)
	// Example response:
	//   Job name: projects/{PROJECT_ID}/locations/us-central1/batchPredictionJobs/9876453210000000000
	//   Job state: JOB_STATE_PENDING

	// See the documentation: https://pkg.go.dev/google.golang.org/genai#BatchJob
	completedStates := map[genai.JobState]bool{
		genai.JobStateSucceeded: true,
		genai.JobStateFailed:    true,
		genai.JobStateCancelled: true,
		genai.JobStatePaused:    true,
	}

	for !completedStates[job.State] {
		time.Sleep(30 * time.Second)

		job, err = client.Batches.Get(ctx, job.Name, nil)
		if err != nil {
			return fmt.Errorf("failed to get batch job: %w", err)
		}

		fmt.Fprintf(w, "Job state: %s\n", job.State)
	}

	// Example response:
	//  Job state: JOB_STATE_PENDING
	//  Job state: JOB_STATE_RUNNING
	//  Job state: JOB_STATE_RUNNING
	//  ...
	//  Job state: JOB_STATE_SUCCEEDED

	return nil
}

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 static com.google.genai.types.JobState.Known.JOB_STATE_CANCELLED;
import static com.google.genai.types.JobState.Known.JOB_STATE_FAILED;
import static com.google.genai.types.JobState.Known.JOB_STATE_PAUSED;
import static com.google.genai.types.JobState.Known.JOB_STATE_SUCCEEDED;

import com.google.genai.Client;
import com.google.genai.types.BatchJob;
import com.google.genai.types.BatchJobDestination;
import com.google.genai.types.BatchJobSource;
import com.google.genai.types.CreateBatchJobConfig;
import com.google.genai.types.GetBatchJobConfig;
import com.google.genai.types.HttpOptions;
import com.google.genai.types.JobState;
import java.util.EnumSet;
import java.util.Optional;
import java.util.Set;
import java.util.concurrent.TimeUnit;

public class BatchPredictionWithGcs {

  public static void main(String[] args) throws InterruptedException {
    // TODO(developer): Replace these variables before running the sample.
    // To use a tuned model, set the model param to your tuned model using the following format:
    // modelId = "projects/{PROJECT_ID}/locations/{LOCATION}/models/{MODEL_ID}
    String modelId = "gemini-2.5-flash";
    String outputGcsUri = "gs://your-bucket/your-prefix";
    createBatchJob(modelId, outputGcsUri);
  }

  // Creates a batch prediction job with Google Cloud Storage.
  public static JobState createBatchJob(String modelId, String outputGcsUri)
      throws InterruptedException {
    // Client Initialization. Once created, it can be reused for multiple requests.
    try (Client client =
        Client.builder()
            .location("global")
            .vertexAI(true)
            .httpOptions(HttpOptions.builder().apiVersion("v1").build())
            .build()) {
      // See the documentation:
      // https://googleapis.github.io/java-genai/javadoc/com/google/genai/Batches.html
      BatchJobSource batchJobSource =
          BatchJobSource.builder()
              // Source link:
              // https://storage.cloud.google.com/cloud-samples-data/batch/prompt_for_batch_gemini_predict.jsonl
              .gcsUri("gs://cloud-samples-data/batch/prompt_for_batch_gemini_predict.jsonl")
              .format("jsonl")
              .build();

      CreateBatchJobConfig batchJobConfig =
          CreateBatchJobConfig.builder()
              .displayName("your-display-name")
              .dest(BatchJobDestination.builder().gcsUri(outputGcsUri).format("jsonl").build())
              .build();

      BatchJob batchJob = client.batches.create(modelId, batchJobSource, batchJobConfig);

      String jobName =
          batchJob.name().orElseThrow(() -> new IllegalStateException("Missing job name"));
      JobState jobState =
          batchJob.state().orElseThrow(() -> new IllegalStateException("Missing job state"));
      System.out.println("Job name: " + jobName);
      System.out.println("Job state: " + jobState);
      // Job name: projects/.../locations/.../batchPredictionJobs/6205497615459549184
      // Job state: JOB_STATE_PENDING

      // See the documentation:
      // https://googleapis.github.io/java-genai/javadoc/com/google/genai/types/BatchJob.html
      Set<JobState.Known> completedStates =
          EnumSet.of(JOB_STATE_SUCCEEDED, JOB_STATE_FAILED, JOB_STATE_CANCELLED, JOB_STATE_PAUSED);

      while (!completedStates.contains(jobState.knownEnum())) {
        TimeUnit.SECONDS.sleep(30);
        batchJob = client.batches.get(jobName, GetBatchJobConfig.builder().build());
        jobState =
            batchJob
                .state()
                .orElseThrow(() -> new IllegalStateException("Missing job state during polling"));
        System.out.println("Job state: " + jobState);
      }
      // Example response:
      // Job state: JOB_STATE_QUEUED
      // Job state: JOB_STATE_RUNNING
      // Job state: JOB_STATE_RUNNING
      // ...
      // Job state: JOB_STATE_SUCCEEDED
      return jobState;
    }
  }
}

Node.js

Before trying this sample, follow the Node.js setup instructions in the Vertex AI quickstart using client libraries. For more information, see the Vertex AI Node.js 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.

const {GoogleGenAI} = require('@google/genai');

const GOOGLE_CLOUD_PROJECT = process.env.GOOGLE_CLOUD_PROJECT;
const GOOGLE_CLOUD_LOCATION =
  process.env.GOOGLE_CLOUD_LOCATION || 'us-central1';
const OUTPUT_URI = 'gs://your-bucket/your-prefix';

async function runBatchPredictionJob(
  outputUri = OUTPUT_URI,
  projectId = GOOGLE_CLOUD_PROJECT,
  location = GOOGLE_CLOUD_LOCATION
) {
  const client = new GoogleGenAI({
    vertexai: true,
    project: projectId,
    location: location,
    httpOptions: {
      apiVersion: 'v1',
    },
  });

  // See the documentation: https://googleapis.github.io/js-genai/release_docs/classes/batches.Batches.html
  let job = await client.batches.create({
    // To use a tuned model, set the model param to your tuned model using the following format:
    // model="projects/{PROJECT_ID}/locations/{LOCATION}/models/{MODEL_ID}"
    model: 'gemini-2.5-flash',
    // Source link: https://storage.cloud.google.com/cloud-samples-data/batch/prompt_for_batch_gemini_predict.jsonl
    src: 'gs://cloud-samples-data/batch/prompt_for_batch_gemini_predict.jsonl',
    config: {
      dest: outputUri,
    },
  });

  console.log(`Job name: ${job.name}`);
  console.log(`Job state: ${job.state}`);

  // Example response:
  //  Job name: projects/%PROJECT_ID%/locations/us-central1/batchPredictionJobs/9876453210000000000
  //  Job state: JOB_STATE_PENDING

  const completedStates = new Set([
    'JOB_STATE_SUCCEEDED',
    'JOB_STATE_FAILED',
    'JOB_STATE_CANCELLED',
    'JOB_STATE_PAUSED',
  ]);

  while (!completedStates.has(job.state)) {
    await new Promise(resolve => setTimeout(resolve, 30000));
    job = await client.batches.get({name: job.name});
    console.log(`Job state: ${job.state}`);
  }

  // Example response:
  //  Job state: JOB_STATE_PENDING
  //  Job state: JOB_STATE_RUNNING
  //  Job state: JOB_STATE_RUNNING
  //  ...
  //  Job state: JOB_STATE_SUCCEEDED

  return job.state;
}

Python

Before trying this sample, follow the Python setup instructions in the Vertex AI quickstart using client libraries. For more information, see the Vertex AI Python 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 time

from google import genai
from google.genai.types import CreateBatchJobConfig, JobState, HttpOptions

client = genai.Client(http_options=HttpOptions(api_version="v1"))
# TODO(developer): Update and un-comment below line
# output_uri = "gs://your-bucket/your-prefix"

# See the documentation: https://googleapis.github.io/python-genai/genai.html#genai.batches.Batches.create
job = client.batches.create(
    # To use a tuned model, set the model param to your tuned model using the following format:
    # model="projects/{PROJECT_ID}/locations/{LOCATION}/models/{MODEL_ID}
    model="gemini-2.5-flash",
    # Source link: https://storage.cloud.google.com/cloud-samples-data/batch/prompt_for_batch_gemini_predict.jsonl
    src="gs://cloud-samples-data/batch/prompt_for_batch_gemini_predict.jsonl",
    config=CreateBatchJobConfig(dest=output_uri),
)
print(f"Job name: {job.name}")
print(f"Job state: {job.state}")
# Example response:
# Job name: projects/.../locations/.../batchPredictionJobs/9876453210000000000
# Job state: JOB_STATE_PENDING

# See the documentation: https://googleapis.github.io/python-genai/genai.html#genai.types.BatchJob
completed_states = {
    JobState.JOB_STATE_SUCCEEDED,
    JobState.JOB_STATE_FAILED,
    JobState.JOB_STATE_CANCELLED,
    JobState.JOB_STATE_PAUSED,
}

while job.state not in completed_states:
    time.sleep(30)
    job = client.batches.get(name=job.name)
    print(f"Job state: {job.state}")
# Example response:
# Job state: JOB_STATE_PENDING
# Job state: JOB_STATE_RUNNING
# Job state: JOB_STATE_RUNNING
# ...
# Job state: JOB_STATE_SUCCEEDED

What's next

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