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.

IMPORTANT: If the requested task does not 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 does not have sufficient permissions to invoke the action, or the parameter values fall outside the specified constraints, the action fails by throwing OperationNotPermitted . For details and example IAM policies, see Using IAM to Manage Access to Amazon SWF Workflows.