About MushroomSync
From ThunderstoreShared server-authoritative config sync used by the other Mushroom mods. No gameplay of its own. Required by Combat Adjustments, Craftable Spawners, Haldor Expansion and Random Yggdrasil.
Mushroom Sync
Shared server-authoritative sync for the Mushroom mods. The host decides, clients follow, and nobody's local .cfg gets rewritten.
It has no gameplay of its own. It exists so the mods that need server-authoritative settings share one implementation instead of four copies of the same 300 lines.
Required by
| Mod | Uses | |---|---| | Combat Adjustments | Config sync | | Craftable Spawners | Config sync | | Haldor Expansion | Config sync | | Random Yggdrasil | Raw channel (world rotations) |
MushroomSync.dll must be installed wherever those are — on every client and on the dedicated server. The release zip ships it alongside them, so extracting MushroomMods-plugins.zip into BepInEx/ is enough.
Using it
Config sync, in a plugin's Awake, before binding settings:
[BepInPlugin(PluginGuid, PluginName, PluginVersion)]
[BepInDependency(MushroomSyncPlugin.PluginGuid)]
public class MyPlugin : BaseUnityPlugin
{
internal static ConfigSync Sync;
private void Awake()
{
Sync = ConfigSync.Create(PluginGuid, PluginVersion, Logger)
.Protecting(Config)
.OnApplied(ReapplyRuntimeState);
EnableThing = Config.Bind("General", "EnableThing", true, "...");
Sync.Register(EnableThing);
Sync.WatchForChanges(Config).Start();
}
}
After that EnableThing.Value returns the host's value on a synced client and the local one everywhere else — no call site needs changing. Where you need to know which you got, or want the local value alongside, use Sync.TryGetSyncedValue(entry, out var v).
OnApplied matters for any mod that bakes settings into game objects: the config changing is not enough, the values have to be pushed back in. It fires both when host values arrive and when they are dropped.
Settings that must stay local
Sync.Exclude(SyncConfigInMultiplayer); // the opt-out itself
Sync.Exclude(GrantTableVersion); // server-only bookkeeping
An excluded entry is never sent and never overlaid.
Opting out
Two gates, deliberately separate:
Sync.GatedBy(() => LockConfiguration.Value); // host: publish, or stay quiet
Sync.AcceptedWhen(() => SyncEnabled.Value); // client: follow a host, or not
GatedBy is a host-side switch — it decides whether this machine publishes when it is the server. Haldor Expansion uses only this: a client with LockConfiguration off still follows a host that has it on.
AcceptedWhen is a client-side opt-out. Combat Adjustments passes the same predicate to both, because its SyncConfigInMultiplayer means "do not sync at all".
Conflating the two is a bug worth naming: a host-side switch that also refused incoming values would stop a client following a server merely because that client would not have shared its own settings when hosting.
Pushing your own data
For anything that is not a config entry, use the channel directly — this is what Random Yggdrasil does for world rotations:
var channel = SyncChannel.Create("MyMod.Thing", PluginVersion, Logger);
channel.WritePayload = pkg => { /* server writes */ };
channel.ReadPayload = pkg => { /* client reads */ };
channel.Cleared = reason => { /* fall back to local */ };
channel.Start();
channel.Broadcast(); // after the server changes something
SyncChannel.ReadCount(pkg) reads a length prefix with a sanity bound, so a corrupt packet cannot make you allocate without limit.
Design
See docs/DESIGN.md for why it is built this way — the layering, why it does not wrap login sockets the way ServerSync did, and why the value overlay is read-only.
Highlights
From source dataLoaders
Runs on BepInEx.
Footprint
Rated a light load on a server.
Last update
Its author last shipped an update 50d ago.
MushroomSync on Nxeon
From our catalogue- One-click install
- Supported on Nxeon Valheim servers, for BepInEx servers. We download it from Thunderstore, place it, and restart the server.
- Server side
- Optional on the server
- Server type needed
- BepInEx
- Server load
- light
- Smallest plan we suggest
- Valheim — 4 GB (4 GB RAM). This follows our own load rating above, not a benchmark.
- Latest build
- 1.0.0, released 2026-09-15
Game versions by loader
| Loader | Game versions | Newest |
|---|---|---|
| BepInEx |
From 1 recorded build of MushroomSync.
Dependencies
- Required: BepInExPack Valheim
Declared by the newest build that lists any. Required ones are installed with it on one-click installs.
Run MushroomSync on a Valheim server
Pick a server or deploy a new one above; it is installed in one click.
What kind of mod it is
From the catalogLibraries & compatibility
Foundations and fixes other mods build on. Usually installed because something else needs it.
Works on a server
From source side supportThunderstore lists server-side support for MushroomSync as optional: it can run on a server, but isn’t required there.
Compatibility
- Game
- Valheim
- Loaders
- BepInEx
- Runs on
- Serveroptional on the server
- Requires
- One-click install needs a BepInEx server.
Verified at the source
- ✓ThunderstoreOfficial listing, checked 2026-10-01Open ↗
- ✓AuthorMushroom_Vikings, as published on Thunderstore
- ✓LicenseNot published by the sourceFree



