Railway provides the ability to seal variable values for extra security. When a variable is sealed, its value is provided to builds and deployments but is never visible in the UI nor can it be retrieved via the API. You can read more about sealed variables in the docs.

Yes, I had read the docs on them, but despite what the docs say they aren't provided to builds or deployments. Tried using them, but my validations started failing because my secrets for auth were now undefined. Do you have to access them on some special object?

Sealed variables are provided to build and deployments just like regular ones. I just tested on one of my services and everything worked correctly. I didn't have to change any of my code, so you use them just like normal env variables, thus you don't have to access them on some special object. They are only used as an extra security layer, making them invisible in the dashboard UI and irretrievable through the API, with some additional caveats to them.