# Sample Function

The following is a sample Lambda function that receives Amazon Cognito User Pools pre-signup event as an input and writes some of the record data to CloudWatch Logs. (Note that anything written to stdout or stderr will be logged as CloudWatch Logs events.)

Please see instructions for setting up the Cognito triggers at https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-identity-pools-working-with-aws-lambda-triggers.html .

```go
package main

import (
	"fmt"

	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
)

// handler is the lambda handler invoked by the `lambda.Start` function call
func handler(event events.CognitoEventUserPoolsPreSignup) (events.CognitoEventUserPoolsPreSignup, error) {
	fmt.Printf("PreSignup of user: %s\n", event.UserName)
	event.Response.AutoConfirmUser = true
	return event, nil
}

func main() {
	lambda.Start(handler)
}
```