Since documents are public on Tonic, a common question is how you can safely interact with APIs or services without exposing your credentials. The answer is to use environment variables.
These work just like the shell environment variables you're used to. You set them on the settings page, and then you can access them in any notebook, like this:
var mySecret = process.env.SECRET;
Everything in your environment stays with your account. When people clone a notebook, your environment won't go with it. Be aware, however, than if you log the value of an environment variable, or return it as the output of a code cell, that will be visible to everyone.
You can have as many variables as you like, and we've also made a few handy integrations that make it easy to get set up with OAuth credentials for popular services. These credentials will never be used by us; they're entirely for you to use in your own notebooks.