## Sample commands necessary setup cross-account permissions for AWS Lambda and Amazon SNS Topic 

Command 1: Run this command in Source AWS Account. Grant permission to Target AWS Account to subscribe to the topic:

	aws sns add-permission --label lambda-access --aws-account-id TargetAccount \
	--topic-arn arn:aws:sns:us-east-1:SourceAccount:SchemaDistributionSNSTopic \
	--action-name Subscribe ListSubscriptionsByTopic Receive

Command 2: Run this command in Target AWS Account. Add Lambda permissions to allow invocation from Amazon SNS Topic in Source Account.

	aws lambda add-permission --function-name ImportLambda \
	--source-arn arn:aws:sns:us-east-1:SourceAccount:SchemaDistributionSNSTopic \
	--statement-id sns-x-account --action "lambda:InvokeFunction" \
	--principal sns.amazonaws.com

Command 3: Subscribe Lambda function to the Amazon SNS Topic in Source Account.

	aws sns subscribe --protocol lambda \
	--topic-arn arn:aws:sns:us-east-1:SourceAccount:SchemaDistributionSNSTopic \
	--notification-endpoint arn:aws:lambda:us-east-1:TargetAccount:function:ImportLambda
	
For more detailed explanation, refer AWS documentation at: https://docs.aws.amazon.com/lambda/latest/dg/with-sns-example.html#with-sns-create-x-account-permissions