It is primarily used to help your RustDesk clients to find each other.
Once this is done, it helps you try and get a direct connection between them.
If this fails and your client and controlled devices cannot talk directly to each other, the relay part of side the server will be used to handle the connection.

I only use RustDesk for a few devices on my local network with no Internet connectivity... Can I still use RustDesk with direct ip access?

Yes, you can!

By default this is turned off for security, however if wish to allow this you can do so by doing steps below:

On the device you wish to control
Go into the Menu and select Enable direct IP...
On the client you are connecting from you can now input the Local IP address or host name the address box and click connect.
the connection is unecrypted, please do not send us issue about this.

hbbs -c, the configuration file format

Supper simple format just a=b on each line, a is the name of the option you see from the --help. e.g. e.g.

port=123456

You can also put them in .env file under the same directory of hbbs/hbbr. hbbs/hbbr reads .env file no matter if you specify -c.

Web client

https://rustdesk.com/docs/en/dev/build/web/

http://web.rustdesk.com/ no https for the time being

Change id, addressbook/api/login and web console?

https://github.com/rustdesk/rustdesk-server/issues/22

https://github.com/rustdesk/rustdesk/discussions/570

https://github.com/rustdesk/rustdesk/issues/509

Hardware requirement for RustDesk server.

The hardware requirements are very low, the minimum configuration of the cloud server is enough, and the CPU and memory requirements are the minimum. Regarding the network size, if the TCP hole punching direct connection fails, the relay traffic will be consumed. The traffic of a relay connection is between 30k-3M/s (1920x1080 screen), depending on the resolution settings and screen update. If it is only for office work demand, the traffic is around 100K/s.

Deploy RustDesk server in intranet.

If you host the server in your intranet with some type of routers, you may have network problem because of NAT hairping,

https://www.reddit.com/r/rustdesk/comments/13fkdyd/comment/jjvm6j1/?utm_source=share&utm_medium=web2x&context=3

https://github.com/rustdesk/rustdesk-server/issues/24#issuecomment-1234029480

https://github.com/rustdesk/rustdesk/issues/732#issuecomment-1300514997

https://github.com/rustdesk/rustdesk/issues/732#issuecomment-1319433120

https://www.reddit.com/r/rustdesk/comments/1174mgw/comment/j9e9avt/?context=3

https://github.com/rustdesk/rustdesk-server/issues/200#issuecomment-1543710510

https://github.com/rustdesk/rustdesk-server/issues/134#issuecomment-1303437173

https://github.com/rustdesk/rustdesk/issues/2573#issuecomment-1408672281

How to update RustDesk server?

https://github.com/techahold/rustdeskinstall/issues/30

Some RustDesk Server installer

https://github.com/techahold/rustdeskinstall

https://github.com/elico/rustdesk-ansible-installer

About self-hosting setup

Most users can make it work following the tutorial: https://rustdesk.com/docs/en/self-host/install/
This two videos should be helpful. https://www.youtube.com/watch?v=9nzHm3xGz2I and https://www.youtube.com/watch?v=EeFqj23jxMk. Another one in French: https://www.youtube.com/watch?v=J7t32K5--cM
Most questions are about Linux and network, which can be Googled and ChatGPTed.
Go to Discord, there may be some nice users help you. Or search in the discord welcome channel, there are many users who have asked similar questions. Whenever, search is your best friend.
If you host the server in your intranet with some type of routers, you may have network problem because of NAT hairping,

https://github.com/rustdesk/rustdesk-server/issues/24#issuecomment-1234029480

https://github.com/rustdesk/rustdesk/issues/732#issuecomment-1300514997

https://github.com/rustdesk/rustdesk/issues/732#issuecomment-1319433120