What kind of errors can or should be handled by the user facing code?

So, lately I have been thinking about API design and this is one of things I can’t really put my finger on it. For the sake of clarity, when I talk about “error” in this post I mean zig errors. Lets say (a hypothetical scenario) in the API there is a function called veryImportantFunction and it can return variety of errors: const VeryImportantFunctionError = error{ OutOfMemory (ofc), InvalidParameter, LostSomethingImportantWhileTheFunctionWasExecuting, SomethingWentWrongWithThe...