Start asynchronous action Lambda

async_invoke.py

def async_invoke_handler(event, context):
    activity_task_response = states_client.get_activity_task(
        activityArn=ASYNC_ACTION_ACTIVITY_ARN,
        workerName=context.function_name,
    )

    if 'taskToken' not in activity_task_response:
        raise MissingScheduledActivityTaskException()

    input_for_nested_execution = {
        'task_token': activity_task_response['taskToken'],
        'state': json.loads(activity_task_response['input']),
    }

    nested_execution_response = states_client.start_execution(
        stateMachineArn=NESTED_STATE_MACHINE_ARN,
        input=json.dumps(input_for_nested_execution),
    )

    return {
        'nested_execution_arn': nested_execution_response['executionArn'],
    }