> For the complete documentation index, see [llms.txt](https://docs.snyk.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.snyk.io/developer-tools/snyk-api/using-specific-snyk-apis/webhooks-apis/guides-to-webhooks/how-to-use-snyk-webhooks-to-connect-snyk-to-slack-with-aws-lambda/aws-lambda-setup-add-security-through-an-environment-variable.md).

# AWS Lambda setup: add security through an environment variable

How to secure the AWS Lambda function with an environment variable

For security reasons the script that you created uses an environment variable: `hmac_verification` with a shared secret to validate the payload is coming from Snyk and has not been tampered with.

Follow these steps to add security through an environment variable:

1. Go to the **Configuration** tab in the AWS Lambda function.
2. Click **Environment variables**.
3. Add the new environment variable.
4. Use `hmac_verification` as your key.
5. Enter your preferred secret as the key value. Store this secret somewhere safe for use again later.
6. For added security, consider using Secrets Manager or Parameter Store for the shared secret.


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