UpdateStateMachineAlias - AWS Step Functions


Updates the configuration of an existing state machine alias by modifying its description or routingConfiguration.

You must specify at least one of the description or routingConfiguration parameters to update a state machine alias.


UpdateStateMachineAlias is an idempotent API. Step Functions bases the idempotency check on the stateMachineAliasArn, description, and routingConfiguration parameters. Requests with the same parameters return an idempotent response.


This operation is eventually consistent. All StartExecution requests made within a few seconds use the latest alias configuration. Executions started immediately after calling UpdateStateMachineAlias may use the previous routing configuration.

Related operations:

Request Syntax

{ "description": "string", "routingConfiguration": [ { "stateMachineVersionArn": "string", "weight": number } ], "stateMachineAliasArn": "string" }

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

The request accepts the following data in JSON format.


A description of the state machine alias.

Type: String

Length Constraints: Maximum length of 256.

Required: No


The routing configuration of the state machine alias.

An array of RoutingConfig objects that specifies up to two state machine versions that the alias starts executions for.

Type: Array of RoutingConfigurationListItem objects

Array Members: Minimum number of 1 item. Maximum number of 2 items.

Required: No


The Amazon Resource Name (ARN) of the state machine alias.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 256.

Required: Yes

Response Syntax

{ "updateDate": number }

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.


The date and time the state machine alias was updated.

Type: Timestamp


For information about the errors that are common to all actions, see Common Errors.


Updating or deleting a resource can cause an inconsistent state. This error occurs when there're concurrent requests for DeleteStateMachineVersion, PublishStateMachineVersion, or UpdateStateMachine with the publish parameter set to true.

HTTP Status Code: 409

HTTP Status Code: 400


The provided Amazon Resource Name (ARN) is not valid.

HTTP Status Code: 400


Could not find the referenced resource.

HTTP Status Code: 400


The specified state machine is being deleted.

HTTP Status Code: 400


The input does not satisfy the constraints specified by an AWS service.

HTTP Status Code: 400

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: