I would like to offer the cooperation mode in my game.
To do this, a few game instances would have to connect.
The first player is the game master, who invites and has a control unit. A kind of chat connection should be enough.
I don’t want to build a game server that handles the game logic. Actually, I didn’t want to run a server at home. This is a bit dangerous in the wild internet. I’d rather use an open one.
Now I’m looking for a (free) chat server.
If I google for chat servers, I get fully professional solutions with video and such for companies. When I google how-to make (java) client, I only get do-it-yurself (server and client) pages.
Does anyone know of a chat server standing around there that I could build my own client for?
Or is the idea of abusing an (open) chat in itself stupid and would you recommend something else?
Otherwise I would have to have a server hosted. That would be a bit too expensive for programming exercises.
This sounds like an abuse of a chat server, though for some very simple non-realtime uses it could work.
Your best bet is probably IRC - it’s an old, well-established and simple protocol, and free IRC channel hosting is easy to come by. You might want to have a look at Libera Chat, for example.
There is firebase(RealTime json db & Firebase Cloud Messaging auth using google acc auth or fb auth or a custom one), you might find it good, you have a stable number of storage each month or so, & it keeps resetting afaik (w/o data delete) & they have gradle support for non-android apps too :
If your server is stateless then a 5$/Month machine on cheap cloud providers such as DigitalOcean running NodeJS with 5-10 lines of server side code using socket.IO and on the client side also a few lines of connection code to the server and you have a fully working chat machine in very small effort.
I tested it with ~80 concurrent connections and it worked fine.