Use PutObjectRetention with an AWS SDK or CLI

    /// <summary>
    /// Set or modify a retention period on an object in an S3 bucket.
    /// </summary>
    /// <param name="bucketName">The bucket of the object.</param>
    /// <param name="objectKey">The key of the object.</param>
    /// <param name="retention">The retention mode.</param>
    /// <param name="retainUntilDate">The date retention expires.</param>
    /// <returns>True if successful.</returns>
    public async Task<bool> ModifyObjectRetentionPeriod(string bucketName,
        string objectKey, ObjectLockRetentionMode retention, DateTime retainUntilDate)
    {
        try
        {
            var request = new PutObjectRetentionRequest()
            {
                BucketName = bucketName,
                Key = objectKey,
                Retention = new ObjectLockRetention()
                {
                    Mode = retention,
                    RetainUntilDate = retainUntilDate
                }
            };

            var response = await _amazonS3.PutObjectRetentionAsync(request);
            Console.WriteLine($"\tSet retention for {objectKey} in {bucketName} until {retainUntilDate:d}.");
            return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
        }
        catch (AmazonS3Exception ex)
        {
            Console.WriteLine($"\tError modifying retention period: '{ex.Message}'");
            return false;
        }
    }

To set an object retention configuration for an object

The following put-object-retention example sets an object retention configuration for the specified object until 2025-01-01.

aws s3api put-object-retention \
    --bucket my-bucket-with-object-lock \
    --key doc1.rtf \
    --retention '{ "Mode": "GOVERNANCE", "RetainUntilDate": "2025-01-01T00:00:00" }'

This command produces no output.

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"log"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/feature/s3/manager"
	"github.com/aws/aws-sdk-go-v2/service/s3"
	"github.com/aws/aws-sdk-go-v2/service/s3/types"
	"github.com/aws/smithy-go"
)

// S3Actions wraps S3 service actions.
type S3Actions struct {
	S3Client  *s3.Client
	S3Manager *manager.Uploader
}



// PutObjectRetention sets the object retention configuration for an S3 object.
func (actor S3Actions) PutObjectRetention(ctx context.Context, bucket string, key string, retentionMode types.ObjectLockRetentionMode, retentionPeriodDays int32) error {
	input := &s3.PutObjectRetentionInput{
		Bucket: aws.String(bucket),
		Key:    aws.String(key),
		Retention: &types.ObjectLockRetention{
			Mode:            retentionMode,
			RetainUntilDate: aws.Time(time.Now().AddDate(0, 0, int(retentionPeriodDays))),
		},
		BypassGovernanceRetention: aws.Bool(true),
	}

	_, err := actor.S3Client.PutObjectRetention(ctx, input)
	if err != nil {
		var noKey *types.NoSuchKey
		if errors.As(err, &noKey) {
			log.Printf("Object %s does not exist in bucket %s.\n", key, bucket)
			err = noKey
		}
	}

	return err
}

    // Set or modify a retention period on an object in an S3 bucket.
    public void modifyObjectRetentionPeriod(String bucketName, String objectKey) {
        // Calculate the instant one day from now.
        Instant futureInstant = Instant.now().plus(1, ChronoUnit.DAYS);

        // Convert the Instant to a ZonedDateTime object with a specific time zone.
        ZonedDateTime zonedDateTime = futureInstant.atZone(ZoneId.systemDefault());

        // Define a formatter for human-readable output.
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");

        // Format the ZonedDateTime object to a human-readable date string.
        String humanReadableDate = formatter.format(zonedDateTime);

        // Print the formatted date string.
        System.out.println("Formatted Date: " + humanReadableDate);
        ObjectLockRetention retention = ObjectLockRetention.builder()
            .mode(ObjectLockRetentionMode.GOVERNANCE)
            .retainUntilDate(futureInstant)
            .build();

        PutObjectRetentionRequest retentionRequest = PutObjectRetentionRequest.builder()
            .bucket(bucketName)
            .key(objectKey)
            .retention(retention)
            .build();

        getClient().putObjectRetention(retentionRequest);
        System.out.println("Set retention for "+objectKey +" in " +bucketName +" until "+ humanReadableDate +".");
    }

import {
  PutObjectRetentionCommand,
  S3Client,
  S3ServiceException,
} from "@aws-sdk/client-s3";

/**
 * Place a 24-hour retention period on an object in an Amazon S3 bucket.
 * @param {{ bucketName: string, key: string }}
 */
export const main = async ({ bucketName, key }) => {
  const client = new S3Client({});
  const command = new PutObjectRetentionCommand({
    Bucket: bucketName,
    Key: key,
    BypassGovernanceRetention: false,
    Retention: {
      // In governance mode, users can't overwrite or delete an object version
      // or alter its lock settings unless they have special permissions. With
      // governance mode, you protect objects against being deleted by most users,
      // but you can still grant some users permission to alter the retention settings
      // or delete the objects if necessary.
      Mode: "GOVERNANCE",
      RetainUntilDate: new Date(new Date().getTime() + 24 * 60 * 60 * 1000),
    },
  });

  try {
    await client.send(command);
    console.log("Object Retention settings updated.");
  } catch (caught) {
    if (
      caught instanceof S3ServiceException &&
      caught.name === "NoSuchBucket"
    ) {
      console.error(
        `Error from S3 while modifying the governance mode and retention period on an object. The bucket doesn't exist.`,
      );
    } else if (caught instanceof S3ServiceException) {
      console.error(
        `Error from S3 while modifying the governance mode and retention period on an object. ${caught.name}: ${caught.message}`,
      );
    } else {
      throw caught;
    }
  }
};

// Call function if run directly
import { parseArgs } from "node:util";
import {
  isMain,
  validateArgs,
} from "@aws-doc-sdk-examples/lib/utils/util-node.js";

const loadArgs = () => {
  const options = {
    bucketName: {
      type: "string",
      required: true,
    },
    key: {
      type: "string",
      required: true,
    },
  };
  const results = parseArgs({ options });
  const { errors } = validateArgs({ options }, results);
  return { errors, results };
};

if (isMain(import.meta.url)) {
  const { errors, results } = loadArgs();
  if (!errors) {
    main(results.values);
  } else {
    console.error(errors.join("\n"));
  }
}

Example 1: The command enables governance retention mode untill the date '31st Dec 2019 00:00:00' for 'testfile.txt' object in the given S3 bucket.

Write-S3ObjectRetention -BucketName 'amzn-s3-demo-bucket' -Key 'testfile.txt' -Retention_Mode GOVERNANCE -Retention_RetainUntilDate "2019-12-31T00:00:00"

Put an object retention.

            s3_client.put_object_retention(
                Bucket=bucket,
                Key=key,
                VersionId=version_id,
                Retention={"Mode": "GOVERNANCE", "RetainUntilDate": far_future_date},
                BypassGovernanceRetention=True,
            )