Use GetObjectRetention with an AWS SDK or CLI

    /// <summary>
    /// Get the retention period for an S3 object.
    /// </summary>
    /// <param name="bucketName">The bucket of the object.</param>
    /// <param name="objectKey">The object key.</param>
    /// <returns>The object retention details.</returns>
    public async Task<ObjectLockRetention> GetObjectRetention(string bucketName,
        string objectKey)
    {
        try
        {
            var request = new GetObjectRetentionRequest()
            {
                BucketName = bucketName,
                Key = objectKey
            };

            var response = await _amazonS3.GetObjectRetentionAsync(request);
            Console.WriteLine($"\tObject retention for {objectKey} in {bucketName}: " +
                              $"\n\t{response.Retention.Mode} until {response.Retention.RetainUntilDate:d}.");
            return response.Retention;
        }
        catch (AmazonS3Exception ex)
        {
            Console.WriteLine($"\tUnable to fetch object lock retention: '{ex.Message}'");
            return new ObjectLockRetention();
        }
    }

To retrieve the object retention configuration for an object

The following get-object-retention example retrieves the object retention configuration for the specified object.

aws s3api get-object-retention \
    --bucket my-bucket-with-object-lock \
    --key doc1.rtf

Output:

{
    "Retention": {
        "Mode": "GOVERNANCE",
        "RetainUntilDate": "2025-01-01T00:00:00.000Z"
    }
}

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
}



// GetObjectRetention retrieves the object retention configuration for an S3 object.
func (actor S3Actions) GetObjectRetention(ctx context.Context, bucket string, key string) (*types.ObjectLockRetention, error) {
	var retention *types.ObjectLockRetention
	input := &s3.GetObjectRetentionInput{
		Bucket: aws.String(bucket),
		Key:    aws.String(key),
	}

	output, err := actor.S3Client.GetObjectRetention(ctx, input)
	if err != nil {
		var noKey *types.NoSuchKey
		var apiErr *smithy.GenericAPIError
		if errors.As(err, &noKey) {
			log.Printf("Object %s does not exist in bucket %s.\n", key, bucket)
			err = noKey
		} else if errors.As(err, &apiErr) {
			switch apiErr.ErrorCode() {
			case "NoSuchObjectLockConfiguration":
				err = nil
			case "InvalidRequest":
				log.Printf("Bucket %s does not have locking enabled.", bucket)
				err = nil
			}
		}
	} else {
		retention = output.Retention
	}

	return retention, err
}

    // Get the retention period for an S3 object.
    public ObjectLockRetention getObjectRetention(String bucketName, String key){
        try {
            GetObjectRetentionRequest retentionRequest = GetObjectRetentionRequest.builder()
                .bucket(bucketName)
                .key(key)
                .build();

            GetObjectRetentionResponse response = getClient().getObjectRetention(retentionRequest);
            System.out.println("tObject retention for "+key +" in "+ bucketName +": " + response.retention().mode() +" until "+ response.retention().retainUntilDate() +".");
            return response.retention();

        } catch (S3Exception e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            return null;
        }
    }

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

/**
 * Log the "RetainUntilDate" for an object in an S3 bucket.
 * @param {{ bucketName: string, key: string }}
 */
export const main = async ({ bucketName, key }) => {
  const client = new S3Client({});

  try {
    const { Retention } = await client.send(
      new GetObjectRetentionCommand({
        Bucket: bucketName,
        Key: key,
      }),
    );
    console.log(
      `${key} in ${bucketName} will be retained until ${Retention.RetainUntilDate}`,
    );
  } catch (caught) {
    if (
      caught instanceof S3ServiceException &&
      caught.name === "NoSuchObjectLockConfiguration"
    ) {
      console.warn(
        `The object "${key}" in the bucket "${bucketName}" does not have an ObjectLock configuration.`,
      );
    } else if (caught instanceof S3ServiceException) {
      console.error(
        `Error from S3 while getting object retention settings for "${bucketName}".  ${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 returns the mode and date till the object would be retained.

Get-S3ObjectRetention -BucketName 'amzn-s3-demo-bucket' -Key 'testfile.txt'