Possible to source environment variables via script only once? Or set up caching?

[krg-digital]

I'm currently sourcing a couple of environment variables from a script which populate those variables with values fetched via the network which works just fine, however this causes quite a delay every time a terminal command is entered and the terminal reloads. One of the variables makes use of an access token, so it does need to be periodically refreshed. I was wondering if there is some caching behavior I can configure for _.source = "./some-script.sh" so that it only sources from that script based on some given time span.

[jdx]

there's some caching support for exec() in templates, we might be able to do something similar for _.source