Keep a copy🙂 We're doing quite a few changes around this API at the moment. We're currently migrating our own components to incorporate those changes before we make the API changes public. Ultimately, we're aiming for Swipeable to live in Foundation and it's unlikely we will open the API in the meantime. No timelines on it except for "near future".
In the meantime, we recommend keeping your own copy though 🙂
May I ask what your use case is?