Amazon Simple Workflow Service
API Reference (API Version 2012-01-25)


Used by workers to tell the service that the ActivityTask identified by the taskToken completed successfully with a result (if provided). The result appears in the ActivityTaskCompleted event in the workflow history.


If the requested task doesn't complete successfully, use RespondActivityTaskFailed instead. If the worker finds that the task is canceled through the canceled flag returned by RecordActivityTaskHeartbeat, it should cancel the task, clean up and then call RespondActivityTaskCanceled.

A task is considered open from the time that it is scheduled until it is closed. Therefore a task is reported as open while a worker is processing it. A task is closed after it has been specified in a call to RespondActivityTaskCompleted, RespondActivityTaskCanceled, RespondActivityTaskFailed, or the task has timed out.

Access Control

You can use IAM policies to control this action's access to Amazon SWF resources as follows:

  • Use a Resource element with the domain name to limit the action to only specified domains.

  • Use an Action element to allow or deny permission to call this action.

  • You cannot use an IAM policy to constrain this action's parameters.

If the caller doesn't have sufficient permissions to invoke the action, or the parameter values fall outside the specified constraints, the action fails. The associated event attribute's cause parameter is set to OPERATION_NOT_PERMITTED. For details and example IAM policies, see Using IAM to Manage Access to Amazon SWF Workflows in the Amazon SWF Developer Guide.

Request Syntax

   "result": "string",
   "taskToken": "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.


The result of the activity task. It is a free form string that is implementation specific.

Type: String

Length Constraints: Maximum length of 32768.

Required: No


The taskToken of the ActivityTask.


taskToken is generated by the service and should be treated as an opaque value. If the task is passed to another process, its taskToken must also be passed. This enables it to provide its progress and respond with results.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 1024.

Required: Yes

Response Elements

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


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


Returned when the caller doesn't have sufficient permissions to invoke the action.

HTTP Status Code: 400


Returned when the named resource cannot be found with in the scope of this operation (region or domain). This could happen if the named resource was never created or is no longer available for this operation.

HTTP Status Code: 400


RespondActivityTaskCompleted Example

Sample Request

User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv: Gecko/20111212 Firefox/3.6.25 ( .NET CLR 3.5.30729; .NET4.0E)
Accept: application/json, text/javascript, */*
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive
Content-Type: application/x-amz-json-1.0
X-Requested-With: XMLHttpRequest
X-Amz-Date: Mon, 16 Jan 2012 03:56:15 GMT
X-Amz-Target: SimpleWorkflowService.RespondActivityTaskCompleted
Content-Encoding: amz-1.0
X-Amzn-Authorization: AWS3 AWSAccessKeyId=AKIAIOSFODNN7EXAMPLE,Algorithm=HmacSHA256,SignedHeaders=Host;X-Amz-Date;X-Amz-Target;Content-Encoding,Signature=M+ygHbMHSHJiVrsAQTW/BfkgHoNzLPnPD+dVywJiPXE=
Content-Length: 638
Pragma: no-cache
Cache-Control: no-cache

{"taskToken": "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",
"result": "customer credit card verified"}

Sample Response

HTTP/1.1 200 OK
Content-Length: 0
Content-Type: application/json
x-amzn-RequestId: 0976f0f4-3ff6-11e1-9a27-0760db01a4a8

See Also

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