You write a function. As an example, here's one way to check if you have a valid AWS credential

``` async function main(component: Input): Promise < Output > { const authCheck = await siExec.waitUntilEnd("aws", [ "sts", "get-caller-identity", "--region", "us-east-1" ]);

    if (authCheck.exitCode === 0) {
        return {
            result: "success",
            message: 'Credentials are Valid'
        };
    }

    return {
        result: "failure",
        message: 'Credentials are invalid. Please check the credentials set on the secret/credentials prop!'
    };

} ```