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v1

latestOpenAPI 3.0.0Apache 2.0 License2026-07-1737274251.5 KB

Starts a Synchronous Express state machine execution. StartSyncExecution is not available for STANDARD workflows.

StartSyncExecution will return a 200 OK response, even if your execution fails, because the status code in the API response doesn't reflect function errors. Error codes are reserved for errors that prevent your execution from running, such as permissions errors, limit errors, or issues with your state machine code and configuration.

This API action isn't logged in CloudTrail.

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

Headers

X-Amz-Target'AWSStepFunctions.StartSyncExecution' required

Request body

stateMachineArnstring required

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

namestring

The name of the execution.

inputstring password
<p>The string that contains the JSON input data for the execution, for example:</p> <p> <code>"{\"first_name\" : \"Alejandro\"}"</code> </p> <note> <p>If you don't include any JSON input data, you still must include the two braces, for example: <code>"{}"</code> </p> </note> <p>Length constraints apply to the payload size, and are expressed as bytes in UTF-8 encoding.</p>
traceHeaderstring
<p>Passes the X-Ray trace header. The trace header can also be passed in the request payload.</p> <note> <p> For X-Ray traces, all Amazon Web Services services use the <code>X-Amzn-Trace-Id</code> header from the HTTP request. Using the header is the preferred mechanism to identify a trace. <code>StartExecution</code> and <code>StartSyncExecution</code> API operations can also use <code>traceHeader</code> from the body of the request payload. If <b>both</b> sources are provided, Step Functions will use the <b>header value</b> (preferred) over the value in the request body. </p> </note>
includedData'ALL_DATA' | 'METADATA_ONLY'

If your state machine definition is encrypted with a KMS key, callers must have <code>kms:Decrypt</code> permission to decrypt the definition. Alternatively, you can call the API with <code>includedData = METADATA_ONLY</code> to get a successful response without the encrypted definition.

Response

Success

executionArnstring required

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

stateMachineArnstring

The Amazon Resource Name (ARN) that identifies the state machine.

namestring

The name of the execution.

startDatestring date-time required

The date the execution is started.

stopDatestring date-time required

If the execution has already ended, the date the execution stopped.

status'SUCCEEDED' | 'FAILED' | 'TIMED_OUT' required

The current status of the execution.

errorstring password

The error code of the failure.

causestring password

A more detailed explanation of the cause of the failure.

inputstring password

The string that contains the JSON input data of the execution. Length constraints apply to the payload size, and are expressed as bytes in UTF-8 encoding.

outputstring password
<p>The JSON output data of the execution. Length constraints apply to the payload size, and are expressed as bytes in UTF-8 encoding.</p> <note> <p>This field is set only if the execution succeeds. If the execution fails, this field is null.</p> </note>
traceHeaderstring
<p>The X-Ray trace header that was passed to the execution.</p> <note> <p> For X-Ray traces, all Amazon Web Services services use the <code>X-Amzn-Trace-Id</code> header from the HTTP request. Using the header is the preferred mechanism to identify a trace. <code>StartExecution</code> and <code>StartSyncExecution</code> API operations can also use <code>traceHeader</code> from the body of the request payload. If <b>both</b> sources are provided, Step Functions will use the <b>header value</b> (preferred) over the value in the request body. </p> </note>