That’s what I thought at first too but apparently Handy’s external API server is still required even if you choose to host the server locally. I’ve been discussing with some other people in this thread: https://discuss.eroscripts.com/t/script-player-handy-over-bluetooth-firmware-3-much-better-expirience/31837/65
As I understand it currently, you can send an API request to HandyFeeling’s API that specifies the script location as on your local network; then it will attempt to download it from that location instead of you uploading it to their servers only for the Handy to download it again. While that works, it doesn’t solve any of the problems: you’re still reliant on their API even for local playback. The only real solution is hosting your own API server, but that won’t happen until they either make it available or someone reverse engineers it.
and
in fact, the guy of Handy Control already reverse engenering the api server, but the handy company add a crypto server validatión in firmware 3.x so even if you clone the api protocol you can not simulate be a oficial handy server. the only way today to upload a funscript to handy is by the handyfeeling api page.
If they’re wrong and you can confirm that the Handy works with a WiFi connection and no actual internet I would love to hear more about it. It would solve all my problems lol.