You can't perform HTTP requests from a pure function without making it obvious in its signature that it does side effects. For example in a language like Haskell:

  add : Int -> Int -> Int
  add x y = x + y

There is no way a function like this can run a Bitcoin miner, all it can do is to return an `Int`. In order to do side effects, a function must return a special `IO` type that should then be returned from `main` (and only then these side effects would be performed).