Nice to meet you. I am from Japan.
We have tried to implement a Direct Message that works on Bluesky using ATProtocol, using RSA and AES encryption, a unique key to the profile, a unique key and date change to the message, and the rest using Notification and it worked well.
The service code is
"out of blue".
https://bluedm.vercel.app/
The message partner must also be logged in at least once. We are 5 days in the making so there are lots of bugs, but try to use it.
Thank you.