API to create/register device

Hi, is there an API which would allow me to create the device? I have several sensors connected to several ESPs in my house (everything on local network). The idea is, I would like to simplify configuration of those ESPs. I woud configure only WiFi network and the blynk server IP. The device would register itself automatically (without a password) for the “default” user and then I could continue in the mobile app.

One possible way, how to implement that is to run a “proxy”. ESP would register to that proxy, the proxy would create a new device on the blynk server and reply by the token and the blynk server IP.