How to store users' BTC wallets?

Question

API

Application for sending / receiving Bitcoin.
After registering a user, you need to create a Bitcoin wallet for him (or the user can import his own).
After that, the user will manage it through the WEB interface (send/receive transactions).
There is a deployed bitcoin node with RPC.
How is it possible to create wallets for users or import them to further create transactions?
+ it is required to unload privateKey to the user, upon request.

Answer 1

https://github.com/bitcoinjs/bitcoinjs-lib and you can implement a full-fledged wallet on the client, even without storing private keys on the server.
or implement everything on the server and on the client a stupid interface