Welcome to the AWS Security Token Service API Reference
AWS provides AWS Security Token Service (AWS STS) as a web service that enables you to request temporary, limited-privilege credentials for users. This guide describes the AWS STS API. For more information, see Temporary Security Credentials in the IAM User Guide.
Note
As an alternative to using the API, you can use one of the AWS SDKs, which consist of
libraries and sample code for various programming languages and platforms such as Java,
Ruby, .NET, iOS, Android, and others. The SDKs provide a convenient way to create
programmatic access to AWS STS. For example, the SDKs can cryptographically sign requests,
manage errors, and retry requests automatically. For information about the AWS SDKs, see
Tools to Build on AWS
For information about setting up signatures and authorization through the API, see Signing AWS API Requests in the Amazon Web Services General Reference. For general information about the Query API, see Making Query Requests in the IAM User Guide. For information about using security tokens with other AWS products, see AWS Services That Work with IAM in the IAM User Guide.
Endpoints
By default, AWS Security Token Service (AWS STS) is available as a global service, and all AWS STS requests
go to a single endpoint at https://sts.amazonaws.com. Global requests map to
the US East (N. Virginia) Region. AWS recommends using Regional AWS STS endpoints instead of
the global endpoint to reduce latency, build in redundancy, and increase session token
validity. For more information, see Managing AWS STS in an
AWS Region in the IAM User Guide.
Most AWS Regions enable operations in all AWS services by default. These Regions automatically activate for use with AWS STS. Some Regions, such as Asia Pacific (Hong Kong), must be manually enabled. To learn more about enabling and disabling AWS Regions, see Managing AWS Regions in the Amazon Web Services General Reference. When you enable these AWS Regions, they are automatically activated for use with AWS STS. You cannot activate the AWS STS endpoint for a disabled Region. Tokens that are valid in all AWS Regions include more characters than tokens that are valid in Regions enabled by default. Changing this setting might affect existing systems where you temporarily store tokens. For more information, see Managing Global Endpoint Session Tokens in the IAM User Guide.
After you activate a Region for use with AWS STS, you can direct AWS STS API calls to that
Region. AWS STS recommends you provide both the Region and endpoint when you send calls to a
Regional endpoint. You can provide the Region alone for manually enabled Regions, such as
Asia Pacific (Hong Kong). In this case, you direct the calls to the AWS STS Regional endpoint.
However, if you provide the Region alone for Regions enabled by default, AWS STS directs the
calls to the global endpoint of https://sts.amazonaws.com.
To view the list of AWS STS endpoints and if they are active by default, see Writing Code to Use AWS STS Regions in the IAM User Guide.
Recording API requests
AWS STS supports AWS CloudTrail, a service that records AWS calls for your AWS account and delivers log files to an Amazon S3 bucket. By using information collected by CloudTrail, you can determine the requests successfully sent to AWS STS, as well as who sent the request, and when it was sent. For more information about CloudTrail, including how to enable it and find your log files, see Logging IAM and AWS STS API calls with AWS CloudTrail in the IAM User Guide and the AWS CloudTrail User Guide.
