Use GetObjectRetention with an Amazon 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"
    }
}

    // 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;
        }
    }

Example 1: The command returns the mode and date till the object would be retained.

Get-S3ObjectRetention -BucketName 's3buckettesting' -Key 'testfile.txt'