There's a particular flavour of disappointment that comes with a client-hosted Core Keeper world. Four of you are finally online at the same time, which took about three weeks of scheduling, and the one person who actually owns the world has gone to bed. The base is sitting right there. Nobody can touch it. That's how co-op works when the world lives on somebody's gaming PC: it exists while they're playing, and it stops existing the second they close the game.
The quieter half of the problem is everything that doesn't happen while the world is shut. Core Keeper is built on slow processes: crops in the ground, cattle in their pens, all the little farms you've wired up to keep yourself in food and bait. None of that ticks when nobody's hosting. You come back after a week away and the world is exactly, uselessly, where you left it.
A dedicated server fixes both, and Pugstorm ships one for free. Here's what running one actually involves, and where the honest edges are.
What a dedicated server changes
The obvious win is that the world stops belonging to one person's machine. Anyone can hop in whenever they like. The friend in a different timezone isn't waiting for you to wake up before they can play.
The less obvious win is that the world keeps running. Crops grow overnight. Your cattle do their thing. If you've built any kind of farm that depends on time passing, it passes whether or not you're logged in, a genuinely different game to the stop-start rhythm of client hosting.
There's also the plain performance argument. Hosting from your own client means your PC is rendering the game and simulating the world for everyone else at the same time, and Core Keeper worlds get heavy as they sprawl. The person hosting always gets the worst experience of anyone in the group. A bit unfair, given they're the one doing everyone a favour.
Self-hosting: what you're signing up for
You can absolutely run this yourself, and I'd never talk anyone out of it if tinkering is part of the fun.
The server is a separate free download on Steam called Core Keeper Dedicated Server, App ID 1963720. It's a Tool rather than a game, so it turns up under Tools in your Steam library, not next to Core Keeper itself. If you'd rather skip the client, SteamCMD pulls it down with an anonymous login:
steamcmd +login anonymous +app_update 1963720 validate +quit
Then you hit the one decision that actually matters, and most guides skate past it. Core Keeper's server runs in two completely different networking modes, and the -port argument is the switch.
Leave -port off and the server uses Steam's relay network. No port forwarding, your home IP stays hidden, and players join with a long generated Game ID. Sounds ideal, and for a quick server on a home connection it often is. The catch is that the relay route is Steam-only, so anyone on the Epic, GOG or Microsoft Store version gets told the host doesn't allow crossplay, and there's nothing they can do from their end.
Set -port and you flip to direct connection. Now people join with a plain IP and port, crossplay across the PC storefronts works, and you're responsible for forwarding UDP on your router. That last part is where home hosting tends to fall over: CGNAT will stop you dead on a lot of consumer connections, and a dynamic IP means your friends' server address quietly breaks every time your ISP feels like it.
Past that it's the usual list. Your machine has to stay on, Windows updates have to not reboot it at 3am, and somebody has to remember to take a backup before a major patch lands.
What you get on a LOW.MS server
We run Core Keeper on bare metal, and the server sits on our network rather than yours, so:
- DDoS protection sits in front of it as standard
- Automatic backups run without you scheduling anything
- You pick your region at checkout, so the server can live near the group rather than near whoever volunteered their PC
- Instant provisioning, so it's live in a couple of minutes rather than an evening
- Full file access through the panel's File Manager, plus SFTP on port 8822 and FTP on 8821 for anything large
- Support tickets answered by people who have actually run these, 24/7
Our servers run with -port set, which is deliberate: you get direct connection mode, an IP and port to hand round, and crossplay that works for the friend who picked the game up on GOG.
Ordering one
Pick a slot count on the Core Keeper server hosting page and check out. You'll get an IP and port emailed over, and the server provisions itself while you're reading the email. If the group grows later, you can move up a tier without losing the world.
First run: what to actually click
Everything lives in the LOW.MS Control Panel. A fresh service generates its world the first time you press start. It takes a minute or two, so don't panic when it isn't instantly joinable.
The bits you'll actually use:
Service Settings is where the server's name lives. Read the next section before you change it.
Commandline Manager holds the launch arguments. Ours look like this:
-world 0 -worldname "<your server name>" -datapath "Saves" -maxplayers <your slots> -port <your port> -ip <your ip> -batchmode -logfile CoreKeeperServerLog.txt
Your slot count and port are filled in from the plan you bought, so there's nothing to set there.
File Manager is where the world lives. Because we pass -datapath "Saves", your saves sit in a Saves folder inside the server's own directory. That's worth knowing: every generic Core Keeper guide will tell you the data lives under AppData\LocalLow\Pugstorm\Core Keeper\DedicatedServer, and on our servers it doesn't.
Steam Update pulls new builds when Pugstorm ships one. Cloud Backup and Cloud Restore cover the "we've made a terrible mistake" scenarios, Scheduled Tasks will restart the server on a timer, and Current Activity & Stats shows who's on.
To join, use Core Keeper's direct connection option and give it your IP and port. That's the route on our servers, not the Game ID.
The world name field is not cosmetic
This is the one I'd flag before you touch anything: it catches people.
The server name in Service Settings feeds straight into -worldname. Core Keeper uses that name to pick which world in the saves folder to load, so it isn't a label sitting on top of your world. It's the key that selects it.
Change the name on a running world and the server won't find a save matching the new one, so it'll helpfully generate a fresh world and drop you in an empty cavern. Your original is still sitting in the Saves folder, perfectly intact. Setting the name back exactly as it was will bring it back. Exactly, though. Capitals and spaces count.
Pick a name you're happy with on day one. If you do need to rename later, take a backup first and expect to move some files around.
Mods: the honest answer
We don't offer mod installation for Core Keeper, and I'd rather say so plainly than bury it.
Two reasons. Core Keeper mods run on BepInEx, which means .dll files, and the panel blocks .dll uploads across every game and every plan we run, as an anti-malware measure. That covers File Manager, SFTP and FTP alike, so the usual "drop it in the plugins folder" workflow silently does nothing.
The other reason is that Pugstorm's own modding story is mid-rebuild. They announced a move to Steam Workshop back in December, and as of the August roadmap it's still an opt-in beta that modders have to join a Steam group to reach. Once that settles into something stable, we'll look at wiring it up properly.
If you want something specific running, open a ticket and we'll tell you honestly whether it's doable.
A few things we've learned
Read the log through File Manager. The server writes CoreKeeperServerLog.txt into its own folder. Core Keeper runs in batch mode with no interactive console, so there's no command prompt to type into, and no in-game admin commands to lean on. The log is your diagnostic.
Take a backup before a major update. That matters more than usual right now. Pugstorm published their 2026 roadmap on 13 August, and 1.3 Riders of the Underground is the first of three "Road to the Maw" updates, due later this year. There's no date yet and I wouldn't guess at one. It's bringing new ways to travel the underground, a new sub-biome, new pets, a legendary item and a rebalance of the mage and summoner playstyles, a lot of surface area for a world that's been running a while.
Your world mode is Normal. Our default command line doesn't pass -worldmode, so that's what you get. If you want Hard, ask us rather than assuming it's a toggle somewhere.
Slots are slots. -maxplayers comes from your plan, so upgrading is how you fit more people in.
Core Keeper is one of the better games to run a persistent server for, because so much of it rewards leaving things alone for a while and coming back. You log in on a Tuesday to find someone's terraformed half the clay caves, the cattle have multiplied, and there's a chest of surplus food nobody asked for. That's the good bit. If you get stuck on any of the above, open a ticket and we'll dig into it with you.