v1

latestOpenAPI 3.0.0Apache 2.0 License2026-07-1426173136.4 KB

Starts a state machine execution. If the given state machine Amazon Resource Name (ARN) is a qualified state machine ARN, it will fail with ValidationException.

A qualified state machine ARN refers to a Distributed Map state defined within a state machine. For example, the qualified state machine ARN arn:partition:states:region:account-id:stateMachine:stateMachineName/mapStateLabel refers to a Distributed Map state with a label mapStateLabel in the state machine named stateMachineName.

StartExecution is idempotent for STANDARD workflows. For a STANDARD workflow, if StartExecution is called with the same name and input as a running execution, the call will succeed and return the same response as the original request. If the execution is closed or if the input is different, it will return a 400 ExecutionAlreadyExists error. Names can be reused after 90 days.

StartExecution is not idempotent for EXPRESS workflows.

post/#X-Amz-Target=AWSStepFunctions.StartExecution

Headers

X-Amz-Target'AWSStepFunctions.StartExecution' required

Request body

stateMachineArnstring required

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

namestring
<p>The name of the execution. This name must be unique for your Amazon Web Services account, region, and state machine for 90 days. For more information, see <a href="https://docs.aws.amazon.com/step-functions/latest/dg/limits.html#service-limits-state-machine-executions"> Limits Related to State Machine Executions</a> in the <i>Step Functions Developer Guide</i>.</p> <p>A name must <i>not</i> contain:</p> <ul> <li> <p>white space</p> </li> <li> <p>brackets <code>&lt; &gt; { } [ ]</code> </p> </li> <li> <p>wildcard characters <code>? *</code> </p> </li> <li> <p>special characters <code>" # % \ ^ | ~ ` $ &amp; , ; : /</code> </p> </li> <li> <p>control characters (<code>U+0000-001F</code>, <code>U+007F-009F</code>)</p> </li> </ul> <p>To enable logging with CloudWatch Logs, the name should only contain 0-9, A-Z, a-z, - and _.</p>
inputstring password
<p>The string that contains the JSON input data for the execution, for example:</p> <p> <code>"input": "{\"first_name\" : \"test\"}"</code> </p> <note> <p>If you don't include any JSON input data, you still must include the two braces, for example: <code>"input": "{}"</code> </p> </note> <p>Length constraints apply to the payload size, and are expressed as bytes in UTF-8 encoding.</p>
traceHeaderstring

Passes the X-Ray trace header. The trace header can also be passed in the request payload.

Response

Success

executionArnstring required

The Amazon Resource Name (ARN) that identifies the execution.

startDatestring date-time required

The date the execution is started.