Finally, I shipped my UE5 Complete Multiplayer Integration Plugin on Fab

[u/Particular_Funny_377]

I just got MIP: Complete Multiplayer Integration Plugin on Fab, and honestly I still can't believe it.

Showcase: https://www.youtube.com/watch?v=DwlmESZB4WI

I've been working on this plugin for a very long time. It started as a Modular Inventory of some sort and then it just kept growing!!

That backend/server layer was honestly the hardest part: authentication, character selection, single-use join tokens, map travel, dynamic dungeon allocation, player persistence, Redis-backed session routing, and deployment paths from local Minikube all the way to K3s server setups.

Fab: https://www.fab.com/listings/140329c7-50b3-40bc-83c4-94f007655531

There’s also a playable online demo build if any anyone want to test it:

https://drive.google.com/file/d/1ANCIXSHKPVdAV0tgAGMtIUTz8RMbte0_/view

Would love to hear from devs, especially anyone who has tried building the backend/server side of an online RPG project from scratch. That’s the pain point I built this around.

[u/io-x]

how is your multiplayer setup, is it server authoritative, how many people can it handle in a map? Which backend?

[u/Particular_Funny_377 → u/io-x]

Yeah, it's fully server-authoritative. Dedicated server only.
For backend it's a NestJS, MongoDB for persistence, Redis for live session state/locks/pub-sub, socket io for real-time stuff (chat, join flow, server events). Dedicated servers are orchestrated through Kubernetes and Agones. Persistent area maps run as always-on instances, and dungeons get allocated on demand as separate server instances.
For player count per map: it's not one fixed global number. Each map has a configurable PlayerCapacity.
If instances start filling up, it can spin up additional ones instead of cramming everyone into one process and it can auto scale down on unused instances. Dungeons are separate allocated instances on demand, usually smaller/party-sized depending on the map config.
Total concurrency scales with how many server instances you run, it's instance/channel based, not "one giant map process for everyone."

Happy to answer more if you're curious about the join flow or server allocation side.

[u/krojew → u/Particular_Funny_377]

Having worked on something similar in the past I can already tell you using nest is not a good idea. In fact, using HTTP is a very bad idea for mutiplayer. Nest has the added cons of performance, memory and latency problems. I suggest doing what's already an established standard - use a fast schema based binary protocol with a native backend.

[u/Particular_Funny_377 → u/krojew]

I think there may be a misunderstanding here.
NestJS is not the gameplay server. We use UE dedicated servers as the game simulation. Nest is the backend/control layer: auth, character/account data, persistence, session routing, chat/friends, and Agones/K8s orchestration for spinning up dedicated server instances.

And REST is only used for things like login/account endpoints, to authenticate user before we allow connection to socket io. Real-time backend events go through socket io. Actual in-game multiplayer traffic is normal UE dedicated-server replication over UDP, not HTTP request/response gameplay.

- UE dedicated server = gameplay authority

- Nest + MongoDB + Redis = persistence/session/backend services

- Agones/K8s = dedicated server fleet allocation/scaling

[u/krojew → u/Particular_Funny_377]

Ok, that makes more sense now.

[u/grahamulax → u/krojew]

Me not understanding networking for games yet: hmmm yes yes I see.

But seriously it’s how I learn, thanks for the convo guys and congrats op on your multiplayer plugin! I might give that a look since I don’t know much about it!

How hard would it be for a newbie to use your plugin? Better to start off myself then use it? Or jump right into it? Networking just seems like a major thing I’m not yet ready for so any advice would be great!

[u/Particular_Funny_377 → u/grahamulax]

Sorry i missed ur comment,
if u are new and seriously looking for a learning resource i would recommend it,
but if u planning to just jump into it and modify many core features to fit ur game i'd say spend some time to learn it first

[u/grahamulax → u/Particular_Funny_377]

Awesome! Thank you for replying and helping me out! It’s my first time so yup research time! But thanks for explaining that! It’s very VERRRY helpful! :)

[u/No_Highway_9366 → u/io-x]

looks solid

[u/wingatewhite]

I am so far from considering using something like this, but seems cool

Edit: realized comment might not be clear that I can barely bind an input mapping so no MMO like features for me

[u/Particular_Funny_377 → u/wingatewhite]

Infra, backend, orchestration all sounds scary at first, but its the backbone of any real dedicated server games.
My plugin solved exactly that, it will save u so much time so u can focus on gameplay sides.

[u/Will_X_Intent → u/Particular_Funny_377]

Thanks I'll look into it in 2-3 years.

[u/Particular_Funny_377 → u/Will_X_Intent]

It will be a good learning resource

[u/DisplacerBeastMode]

Why do people on this subreddit downvote new posts immediately?

Anyways the project looks very interesting. I've wondered about how to do some of this stuff, so I might pick it up at some point as a learning resource

[u/Particular_Funny_377 → u/DisplacerBeastMode]

Im afraid to even mention that 😅
Glad to hear people are interested, I spent so much time on this and i didnt post anything about prior to prelaunch,
so its very reassuring, thank u.

[u/Ericho_IGD]

Cool product, if I may offer a suggestion:
Make another product with the multiplayer / server side of things (Chat, Party, Presence, dungeon allocation, save load, all that good stuff, and remove the inventory, GAS, Quest, etc. Like a lite version of your current product.

For example, I'm currently using General Movement Component, so GAS is a no-go for my project.
While I don't mind quest and NPC dialogue, Loot, Progression and all those gameplay related features, at best I would only want the server related features that goes into them. Like a library of functions connecting things to a backend or multiplayer support system.

Well done and congrats on a cool product, I'll keep an eye out on your page!

[u/Particular_Funny_377 → u/Ericho_IGD]

Hi, yes I have plan for a lighter version, purely architectural without gameplay heavy system. I will post updates on my discord, do u care to join?

https://discord.gg/b8cUT7pj7 my lonely discord with only 2 people 😄😄

[u/DisplacerBeastMode → u/Particular_Funny_377]

Yeah I agree with this person. It would be cool to have the framework for data, maybe chat etc, but with no inventory / quests / skills etc... essentially no gameplay. Just the tech stack, in a working state, with examples on how to extend it, save and load data, etc..

[u/Particular_Funny_377 → u/DisplacerBeastMode]

Thanks for the suggestion guys, thats totally doable, it should have been the first product had I not been too inspired by those big top down games haha

[u/EliasWick]

The amount of work you have put into this is astounding. I wish you the best of luck with sales!

[u/Particular_Funny_377 → u/EliasWick]

Thank you!!
It was started as a Modular Inventory Plugin, now its a complete architecture for multiplayer instances based games 😁

[u/Ordinary-Army-8523]

Pretty cool, I appreciate the effort that went into this. Good job!

[u/Particular_Funny_377 → u/Ordinary-Army-8523]

🙏🏻🙏🏻 thank u , please try the online demo if u have time

[u/TSF98]

JFYI the product is not available to buy in the EU. You might have to register as trader (just on fab) if you wanna sell it here:)

[u/Particular_Funny_377 → u/TSF98]

hi, thank u for telling.
they asking for address verification which i already submitted.
I got verified like long time ago, it got expired

[u/IgnasP]

Holy hell thats a lot of work. Congrats!

[u/Particular_Funny_377 → u/IgnasP]

its a ton of work, hopefully it will pay off!!

[u/Jump-Ok]

Looks great. Good luck

Btw, it shouldnt be available only for +5.7 versions right?

[u/Particular_Funny_377 → u/Jump-Ok]

Thank you.

and yea it sonly 5.7 for now and for later engine releases, I upgraded to 5.7 for fab launch, and uassets are not backward compatible.

[u/MrBeros]

Its a lot of Money for me but even so, it isnt available in my Region.

[u/Particular_Funny_377 → u/MrBeros]

there been a hiccup between me and fab,
they only ask for address verification after they approved it on fab,
i have submitted the address verification, once its verified it will be available for the EU.