LanternServer is the open-source host control service for Lantern multiplayer in Grounded 2. It coordinates save snapshots and restores, exposes the join and admin HTTP APIs, answers Source A2S query, and runs Source RCON. The host's lifecycle wrapper owns the Grounded 2 process so panel-managed and self-hosted service managers have one lifecycle owner rather than two competing restart loops.
Players join with the Lantern desktop app. A playable host also needs Lantern's in-game runtime — a ue4ss\ folder with the host mod and native runtime, plus the WARP redist — next to the LanternServer\ folder. The release zip bundles that runtime, so a downloaded server is complete. Building from this source yourself produces the control service only.
Tracks the Lantern runtime heartbeat and coordinates save operations with the host's Grounded 2 lifecycle wrapper.
Snapshots the world on every game auto-save (when SnapshotsEnabled is on) and on admin trigger. Restore swaps the save directory atomically, so a failed restore does not leave a half-written world.
Answers standard Source A2S query on the query port so server lists, monitoring tools, and bots can read server name, map, and player count.
Runs a Source-compatible RCON listener with help, status, players, ping, save snapshot, save list, say, announce, and motd.
Exposes health, info, players, mod manifest, chat, map state, and the snapshot list/download/restore/import routes. Admin routes are HMAC-signed with a key derived from the RCON password.
Loads UE4SS Lua and native mods through the Lantern runtime layout, and publishes the server's mod manifest at GET /api/v1/manifest for the launcher to install on join.
- Windows 10/11 or Windows Server, x64
- Grounded 2 game files installed on the host machine (the lifecycle wrapper launches them; Lantern does not ship the game)
- Open/forwarded ports for gameplay, query, RCON, and admin HTTP
The hosted game runs headless on the WARP software renderer, so no GPU is required. Release builds are self-contained; a separate .NET install is not needed for normal use.
SurvivalServers.com Grounded 2 hosting ships the complete Lantern server runtime already installed and handles ports, updates, and panel integration.
- Download
LanternServer-v<version>.zipfrom the latest release. - Extract it to a stable folder on the Windows host. It contains
LanternServer\(the supervisor andappsettings.json),ue4ss\(the in-game runtime),redist\(the WARP renderer and the UE4SS proxy),engine-ini\(host and client templates),host-instance.ps1, andsteam_appid.txt. - Install Grounded 2 on the host and keep Steam logged in.
- Edit
LanternServer\appsettings.json. - Open/forward the ports below. The gameplay UDP port also needs a Windows Defender inbound allow rule, or players cannot reach the listen socket.
- Launch Grounded 2 through the lifecycle wrapper, then run
LanternServer\LanternServer.exefor query, RCON, world tools, and join identity. The bundledhost-instance.ps1is the reference launch wrapper for self-hosted installs.
Players connect with the Lantern app to <host>:<GameplayPort>.
Every port is derived from the gameplay port, so a host only configures one.
| Offset | Default | Purpose | Proto |
|---|---|---|---|
| +0 | 7777 | Gameplay, the join port | UDP |
| +1 | 7778 | Control / IPC identifier, local only | — |
| +2 | 7779 | Server query (Source A2S) | UDP |
| +3 | 7780 | RCON (Source RCON) | TCP |
| +4 | 7781 | Admin HTTP API | TCP |
LanternServer reads appsettings.json next to LanternServer.exe, under the Lantern section. At minimum set InstanceId, GameplayPort, RconPassword, and ServerName. Mods settings nest under the Lantern block, not at the top level.
src/server/LanternServer— host control service, HTTP admin API, watchdogsrc/server/Lantern.Rcon— Source RCON serversrc/server/Lantern.SourceQuery— Source A2S query respondersrc/server/Lantern.Persistence— save/snapshot storagesrc/shared/Lantern.Abstractions,src/shared/Lantern.Protocol— shared contracts
dotnet build src/server/LanternServer/LanternServer.csproj -c ReleaseSee LICENSE.