Use CreateAlias with an AWS SDK or CLI

    using System;
    using System.Threading.Tasks;
    using Amazon.KeyManagementService;
    using Amazon.KeyManagementService.Model;

    /// <summary>
    /// Creates an alias for an AWS Key Management Service (AWS KMS) key.
    /// </summary>
    public class CreateAlias
    {
        public static async Task Main()
        {
            var client = new AmazonKeyManagementServiceClient();

            // The alias name must start with alias/ and can be
            // up to 256 alphanumeric characters long.
            var aliasName = "alias/ExampleAlias";

            // The value supplied as the TargetKeyId can be either
            // the key ID or key Amazon Resource Name (ARN) of the
            // AWS KMS key.
            var keyId = "1234abcd-12ab-34cd-56ef-1234567890ab";

            var request = new CreateAliasRequest
            {
                AliasName = aliasName,
                TargetKeyId = keyId,
            };

            var response = await client.CreateAliasAsync(request);

            if (response.HttpStatusCode == System.Net.HttpStatusCode.OK)
            {
                Console.WriteLine($"Alias, {aliasName}, successfully created.");
            }
            else
            {
                Console.WriteLine($"Could not create alias.");
            }
        }
    }

To create an alias for a KMS key

The following create-alias command creates an alias named example-alias for the KMS key identified by key ID 1234abcd-12ab-34cd-56ef-1234567890ab.

Alias names must begin with alias/. Do not use alias names that begin with alias/aws; these are reserved for use by AWS.

aws kms create-alias \
    --alias-name alias/example-alias \
    --target-key-id 1234abcd-12ab-34cd-56ef-1234567890ab

This command doesn't return any output. To see the new alias, use the list-aliases command.

For more information, see Using aliases in the AWS Key Management Service Developer Guide.

    /**
     * Creates a custom alias for the specified target key asynchronously.
     *
     * @param targetKeyId the ID of the target key for the alias
     * @param aliasName   the name of the alias to create
     * @return a {@link CompletableFuture} that completes when the alias creation operation is finished
     */
    public CompletableFuture<Void> createCustomAliasAsync(String targetKeyId, String aliasName) {
        CreateAliasRequest aliasRequest = CreateAliasRequest.builder()
            .aliasName(aliasName)
            .targetKeyId(targetKeyId)
            .build();

        CompletableFuture<CreateAliasResponse> responseFuture = getAsyncClient().createAlias(aliasRequest);
        responseFuture.whenComplete((response, exception) -> {
            if (exception == null) {
                logger.info("{} was successfully created.", aliasName);
            } else {
                if (exception instanceof ResourceExistsException) {
                    logger.info("Alias [{}] already exists. Moving on...", aliasName);
                } else if (exception instanceof KmsException kmsEx) {
                    throw new RuntimeException("KMS error occurred while creating alias: " + kmsEx.getMessage(), kmsEx);
                } else {
                    throw new RuntimeException("An unexpected error occurred while creating alias: " + exception.getMessage(), exception);
                }
            }
        });

        return responseFuture.thenApply(response -> null);
    }

suspend fun createCustomAlias(
    targetKeyIdVal: String?,
    aliasNameVal: String?,
) {
    val request =
        CreateAliasRequest {
            aliasName = aliasNameVal
            targetKeyId = targetKeyIdVal
        }

    KmsClient { region = "us-west-2" }.use { kmsClient ->
        kmsClient.createAlias(request)
        println("$aliasNameVal was successfully created")
    }
}

    /***
     * @param string $keyId
     * @param string $alias
     * @return void
     */
    public function createAlias(string $keyId, string $alias)
    {
        try{
            $this->client->createAlias([
                'TargetKeyId' => $keyId,
                'AliasName' => $alias,
            ]);
        }catch (KmsException $caught){
            if($caught->getAwsErrorMessage() == "InvalidAliasNameException"){
                echo "The request was rejected because the specified alias name is not valid.";
            }
            throw $caught;
        }
    }

class AliasManager:
    def __init__(self, kms_client):
        self.kms_client = kms_client
        self.created_key = None

    @classmethod
    def from_client(cls) -> "AliasManager":
        """
        Creates an AliasManager instance with a default KMS client.

        :return: An instance of AliasManager initialized with the default KMS client.
        """
        kms_client = boto3.client("kms")
        return cls(kms_client)


    def create_alias(self, key_id: str, alias: str) -> None:
        """
        Creates an alias for the specified key.

        :param key_id: The ARN or ID of a key to give an alias.
        :param alias: The alias to assign to the key.
        """
        try:
            self.kms_client.create_alias(AliasName=alias, TargetKeyId=key_id)
        except ClientError as err:
            if err.response["Error"]["Code"] == "AlreadyExistsException":
                logger.error(
                    "Could not create the alias %s because it already exists.", key_id
                )
            else:
                logger.error(
                    "Couldn't encrypt text. Here's why: %s",
                    err.response["Error"]["Message"],
                )
                raise