# Setting up the IAM policy for asynchronous synthesis
<a name="asynchronous-iam"></a>

In order to use the asynchronous synthesis functionality, you will need an IAM policy that allows the following: 
+ use of new Amazon Polly operations
+ writing to the output S3 bucket
+ publishing to the status SNS topic [optional] 

The following policy grants only the necessary permissions required for asynchronous synthesis and can be attached to the IAM user.