Making API requests Identity Providers Conventions DNS and Endpoints

AWS Transfer Family API Reference

The complete API Reference guide for Transfer Family is available at AWS Transfer Family API Reference.

AWS Transfer Family is a secure transfer service that you can use to transfer files into and out of Amazon Simple Storage Service (Amazon S3) storage over the following protocols:

Secure Shell (SSH) File Transfer Protocol (SFTP)
File Transfer Protocol Secure (FTPS)
File Transfer Protocol (FTP)
Applicability Statement 2 (AS2)

Servers, users, and roles are all identified by their Amazon Resource Name (ARN). You can assign tags, which are key-value pairs, to entities with an ARN. Tags are metadata that can be used to group or search for these entities. One example where tags are useful is for accounting purposes.

The following conventions are observed in AWS Transfer Family ID formats:

ServerId values take the form s-01234567890abcdef.
SshPublicKeyId values take the form key-01234567890abcdef.

Amazon Resource Name (ARN) formats take the following form:

For servers, ARNs take the form arn:aws:transfer:region:account-id:server/server-id.

An example of a server ARN is: arn:aws:transfer:us-east-1:123456789012:server/s-01234567890abcdef.
For users, ARNs take the form arn:aws:transfer:region:account-id:user/server-id/username.

An example is arn:aws:transfer:us-east-1:123456789012:user/s-01234567890abcdef/user1.

DNS entries (endpoints) in use are as follows:

API endpoints take the form transfer.region.amazonaws.com.
Server endpoints take the form server-id.server.transfer.region.amazonaws.com.

This API interface reference for AWS Transfer Family contains documentation for a programming interface that you can use to manage AWS Transfer Family. The reference structure is as follows:

For the alphabetical list of API actions, see Actions.
For the alphabetical list of data types, see Types.
For a list of common query parameters, see Common Parameters.
For descriptions of the error codes, see Common Errors.

Tip

Rather than actually running a command, you can use the --generate-cli-skeleton parameter with any API call to generate and display a parameter template. You can then use the generated template to customize and use as input on a later command. For details, see Generate and use a parameter skeleton file.

Making API requests

In addition to using the console, you can use the AWS Transfer Family API to programmatically configure and manage your servers. This section describes the AWS Transfer Family operations, request signing for authentication and the error handling. For information about the regions and endpoints available for Transfer Family, see AWS Transfer Family endpoints and quotas in the AWS General Reference

Note

You can also use the AWS SDKs when developing applications with Transfer Family;. The AWS SDKs for Java, .NET, and PHP wrap the underlying Transfer Family API, simplifying your programming tasks. For information about downloading the SDK libraries, see Sample code libraries.

Transfer Family required request headers

This section describes the required headers that you must send with every POST request to AWS Transfer Family. You include HTTP headers to identify key information about the request including the operation you want to invoke, the date of the request, and information that indicates the authorization of you as the sender of the request. Headers are case insensitive and the order of the headers is not important.

The following example shows headers that are used in the ListServers operation.


POST / HTTP/1.1
Host: transfer.us-east-1.amazonaws.com
x-amz-target: TransferService.ListServers
x-amz-date: 20220507T012034Z
Authorization: AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20220507/us-east-1/transfer/aws4_request,
    SignedHeaders=content-type;host;x-amz-date;x-amz-target,
    Signature=13550350a8681c84c861aac2e5b440161c2b33a3e4f302ac680ca5b686de48de
Content-Type: application/x-amz-json-1.1
Content-Length: 17

{"MaxResults":10}

The following are the headers that must include with your POST requests to Transfer Family. Headers shown below that begin with "x-amz" are specific for AWS. All other headers listed are common header used in HTTP transactions.

Transfer Family request inputs and signing

All request inputs must be sent as part of JSON payload in request body. For Actions in which all request fields are optional, for example ListServers, you still need to provide an empty JSON object in the request body, such as {}. The structure of Transfer Family payload request/response is documented in existing the API reference, for example DescribeServer.

Transfer Family supports authentication using AWS Signature Version 4. For details, see Signing AWS API requests.

Error responses

When there is an error, the response header information contains:

Content-Type: application/x-amz-json-1.1
An appropriate 4xx or 5xx HTTP status code

The body of an error response contains information about the error that occurred. The following sample error response shows the output syntax of response elements common to all error responses.


{
    "__type": "String",
    "Message": "String", <!-- Message is lowercase in some instances -->
    "Resource": "String",
    "ResourceType": "String",
    "RetryAfterSeconds": "String"
}

The following table explains the JSON error response fields shown in the preceding syntax.

__type

One of the exceptions from a Transfer Family API call.

Type: String

Message or message

One of the operation error code messages.

Note

Some exceptions use message, and others use Message. You can check the code for your interface to determine the proper case. Alternatively, you can test each option to see which works.

Type: String

Resource

The resource for which the error is invoked. For example, if you try to create a user that already exists, the Resource is the username for the existing user.

Type: String

ResourceType

The resource type for which the error is invoked. For example, if you try to create a user that already exists, the ResourceType is User.

Type: String

RetryAfterSeconds

The number of seconds to wait before retrying the command.

Type: String

Error response examples

The following JSON body is returned if you call the DescribeServer API and specify a server that does not exist.


{
  "__type": "ResourceNotFoundException",
  "Message": "Unknown server",
  "Resource": "s-11112222333344444",
  "ResourceType": "Server"
}

The following JSON body is returned if executing an API causes throttling to occur.


{
   "__type":"ThrottlingException",
   "RetryAfterSeconds":"1"
}

The following JSON body is returned if you use the CreateServer API and you do not have sufficient permissions to create a Transfer Family server.


{
  "__type": "AccessDeniedException",
  "Message": "You do not have sufficient access to perform this action."
}

The following JSON body is returned if you use the CreateUser API and specify a user that already exists.


{
  "__type": "ResourceExistsException",
  "Message": "User already exists",
  "Resource": "Alejandro-Rosalez",
  "ResourceType": "User"
}

Available libraries

AWS provides libraries, sample code, tutorials, and other resources for software developers who prefer to build applications using language-specific APIs instead of the command-line tools and Query API. These libraries provide basic functions (not included in the APIs), such as request authentication, request retries, and error handling so that it is easier to get started. See Tools to build on AWS

For libraries and sample code in all languages, see Sample code & libraries.

Identity Providers

AWS Transfer Family supports multiple identity provider types to authenticate and manage users. Each server can use only one authentication method, which must be selected when the server is created.

Service Managed

With the SERVICE_MANAGED authentication method, user credentials are stored and managed within AWS Transfer Family. Users are authenticated using SSH public keys that are associated with their username on the server.

Each user can have one or more SSH public keys stored in the service. When a client requests a file operation, it provides the username and SSH private key, which is authenticated against the stored public key.

Directory Service

The AWS_DIRECTORY_SERVICE authentication method allows you to integrate with AWS Directory Service for Microsoft Active Directory (AWS Directory Service for Microsoft Active Directory).

This option enables you to manage user authentication and access through your existing Active Directory groups. Users can authenticate using their Active Directory credentials.

There is a default limit of 100 Active Directory groups per server, which can be increased to a maximum of 150 groups through a service limit increase.

Lambda

The AWS_LAMBDA authentication method allows you to connect to a custom identity provider using AWS Lambda.

This option provides flexibility to integrate with your existing identity management systems. The Lambda function is responsible for authenticating users and returning the appropriate access policies.

Custom (API Gateway)

The API_GATEWAY authentication method (displayed as Custom in the console) allows you to use a custom authentication method that provides both user authentication and access control.

This method relies on the Amazon API Gateway to use your API call from your identity provider to validate user requests. You might use this custom method to authenticate users against a directory service, a database name/password pair, or some other mechanism.

For all authentication methods, users are assigned policies that define their access to Amazon S3 buckets or Amazon Elastic File System file systems. The server inherits the trust relationship from the user through an IAM role with an AssumeRole action, allowing it to perform file operations on behalf of the user.

Naming Conventions

AWS Transfer Family uses standardized formats for resource identifiers and Amazon Resource Names (ARNs). Understanding these conventions is important when working with the AWS Transfer Family API.

ID Formats

The following conventions are observed in AWS Transfer Family ID formats:

Server IDs: ServerId values take the form s-01234567890abcdef.
SSH Public Key IDs: SshPublicKeyId values take the form key-01234567890abcdef.
Connector IDs: ConnectorId values take the form c-01234567890abcdef.
Workflow IDs: WorkflowId values take the form w-01234567890abcdef.
Profile IDs: ProfileId values take the form p-01234567890abcdef.
WebApp IDs: WebAppId values take the form webapp-01234567890abcdef.

ARN Formats

Amazon Resource Name (ARN) formats take the following form:

Server ARNs

For servers, ARNs take the form arn:aws:transfer:region:account-id:server/server-id.

Example: arn:aws:transfer:us-east-1:123456789012:server/s-01234567890abcdef.

User ARNs

For users, ARNs take the form arn:aws:transfer:region:account-id:user/server-id/username.

Example: arn:aws:transfer:us-east-1:123456789012:user/s-01234567890abcdef/user1.

Connector ARNs

For connectors, ARNs take the form arn:aws:transfer:region:account-id:connector/connector-id.

Example: arn:aws:transfer:us-east-1:123456789012:connector/c-01234567890abcdef.

Workflow ARNs

For workflows, ARNs take the form arn:aws:transfer:region:account-id:workflow/workflow-id.

Example: arn:aws:transfer:us-east-1:123456789012:workflow/w-01234567890abcdef.

WebApp ARNs

For web applications, ARNs take the form arn:aws:transfer:region:account-id:webapp/webapp-id.

Example: arn:aws:transfer:us-east-1:123456789012:webapp/webapp-01234567890abcdef.

You can assign tags, which are key-value pairs, to entities with an ARN. Tags are metadata that can be used to group or search for these entities. One example where tags are useful is for accounting purposes.

DNS and Endpoints

AWS Transfer Family uses standardized DNS naming conventions for both API endpoints and server endpoints. Understanding these endpoints is essential for configuring clients and making API calls.

API Endpoints

API endpoints are used for making API calls to manage AWS Transfer Family resources. These endpoints take the following forms:

Standard API Endpoints

Standard API endpoints take the form transfer.region.amazonaws.com.

Example: transfer.us-east-1.amazonaws.com

Dual-Stack API Endpoints

AWS Transfer Family offers dual-stack API endpoints that can be accessed using either IPv4 or IPv6 requests:

https://transfer.region-code.api.aws
https://transfer-fips.region-code.api.aws

Server Endpoints

Server endpoints are used by file transfer clients to connect to AWS Transfer Family servers. These endpoints take the following forms:

Standard Server Endpoints

Standard server endpoints take the form server-id.server.transfer.region.amazonaws.com.

Example: s-01234567890abcdef.server.transfer.us-east-1.amazonaws.com

Custom Hostnames

You can also configure custom hostnames for your AWS Transfer Family servers. Custom hostnames can be used to provide a more user-friendly or branded experience for your users.

To use a custom hostname, you must:

Own the domain name
Provide a valid certificate
Configure DNS records to point to your AWS Transfer Family server

For a complete list of AWS Transfer Family endpoints by AWS Region, see the AWS Transfer Family endpoints and quotas in the AWS General Reference.

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Document Conventions

AS2 issues

Document history