You may already have this. sl_lib ships inside every ScriptLab script, and the copy you have is the one you need. This listing exists so it can be downloaded and updated on its own - there is nothing to buy.

Nine modules, one global

Callbacks, cache, locales, markers, screen blur, 3D framing, Discord logging, a levelled console and the small utilities. All of it under SL, and nothing else added to the global table.

Loaded as source, not called across

One line in your manifest and the code runs inside YOUR resource, so there is no cross-resource hop on a call you make sixty times a second - and the garbage collector cleans it up when your resource stops.

Callbacks that cannot be flooded

Server callbacks are rate limited per player, sixty a second, because the event a client uses to ask a question is an event a client can spam.

Translations without a rebuild

Every string lives in a JSON file, and the same dictionary is handed straight to the React interfaces - so nothing is ever translated twice. Adding a language is a new file.