# Endpoint discovery
<a name="feature-endpoint-discovery"></a>

**Note**  
For help in understanding the layout of settings pages, or in interpreting the **Support by AWS SDKs and tools** table that follows, see [Understanding the settings pages of this guide](settings-reference.md#settingsPages).

SDKs use endpoint discovery to access service endpoints (URLs to access various resources), while still maintaining flexibility for AWS to alter URLs as needed. This way, your code can automatically detect new endpoints. There are no fixed endpoints for some services. Instead, you get the available endpoints during runtime by making a request to get the endpoints first. After retrieving the available endpoints, the code then uses the endpoint to access other operations. For example, for Amazon Timestream, the SDK makes a `DescribeEndpoints` request to retrieve the available endpoints, and then uses those endpoints to complete specific operations such as `CreateDatabase` or `CreateTable`.

Configure this functionality by using the following:

**`endpoint_discovery_enabled` - shared AWS `config` file setting`AWS_ENABLE_ENDPOINT_DISCOVERY` - environment variable`aws.endpointDiscoveryEnabled` - JVM system property: Java/Kotlin onlyTo configure value directly in code, consult your specific SDK directly. **  
Turns on or off endpoint discovery for DynamoDB.   
Endpoint discovery is required in Timestream and optional in Amazon DynamoDB. This setting defaults to either `true` or `false` depending on whether the service requires endpoint discovery. Timestream requests default to `true`, and Amazon DynamoDB requests default to `false`.   
**Valid values:**  
+ **`true`** – The SDK should automatically attempt to discover an endpoint for services where endpoint discovery is optional.
+ **`false`** – The SDK should not automatically attempt to discover an endpoint for services where endpoint discovery is optional.

## Support by AWS SDKs and tools
<a name="endpoint-discovery-sdk-compat"></a>

The following SDKs support the features and settings described in this topic. Any partial exceptions are noted. Any JVM system property settings are supported by the AWS SDK for Java and the AWS SDK for Kotlin only.


| SDK | Supported | Notes or more information | 
| --- | --- | --- | 
| [AWS CLI v2](https://docs.aws.amazon.com/cli/latest/userguide/) | Yes |  | 
| [SDK for C\$1\$1](https://docs.aws.amazon.com/sdk-for-cpp/latest/developer-guide/) | Yes |  | 
| [SDK for Go V2 (1.x)](https://docs.aws.amazon.com/sdk-for-go/v2/developer-guide/) | Yes |  | 
| [SDK for Go 1.x (V1)](https://docs.aws.amazon.com/sdk-for-go/latest/developer-guide/) | Yes | To use shared config file settings, you must turn on loading from the config file; see [Sessions](https://docs.aws.amazon.com/sdk-for-go/api/aws/session/). | 
| [SDK for Java 2.x](https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/) | Yes | The SDK for Java 2.x uses AWS\$1ENDPOINT\$1DISCOVERY\$1ENABLED for the environment variable name. | 
| [SDK for Java 1.x](https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/) | Partial | JVM system property not supported. | 
| [SDK for JavaScript 3.x](https://docs.aws.amazon.com/sdk-for-javascript/latest/developer-guide/) | Yes |  | 
| [SDK for JavaScript 2.x](https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/) | Yes |  | 
| [SDK for Kotlin](https://docs.aws.amazon.com/sdk-for-kotlin/latest/developer-guide/) | Yes |  | 
| [SDK for .NET 4.x](https://docs.aws.amazon.com/sdk-for-net/latest/developer-guide/) | Yes |  | 
| [SDK for .NET 3.x](https://docs.aws.amazon.com/sdk-for-net/v3/developer-guide/) | Yes |  | 
| [SDK for PHP 3.x](https://docs.aws.amazon.com/sdk-for-php/latest/developer-guide/) | Yes |  | 
| [SDK for Python (Boto3)](https://boto3.amazonaws.com/v1/documentation/api/latest/guide/quickstart.html) | Yes |  | 
| [SDK for Ruby 3.x](https://docs.aws.amazon.com/sdk-for-ruby/latest/developer-guide/) | Yes |  | 
| [SDK for Rust](https://docs.aws.amazon.com/sdk-for-rust/latest/dg/) | Partial | Supported for Timestream only. | 
| [SDK for Swift](https://docs.aws.amazon.com/sdk-for-swift/latest/developer-guide/) | No |  | 
| [Tools for PowerShell V5](https://docs.aws.amazon.com/powershell/latest/userguide/) | Yes |  | 
| [Tools for PowerShell V4](https://docs.aws.amazon.com/powershell/v4/userguide/) | Yes |  |