ServerConfigSync

Make every player on your Valheim server use the server's settings for any mod, even mods that have no server sync of their own.

Many mods read their settings from a BepInEx .cfg file on each player's PC. Without a sync system, every player can have different values: stack sizes, arrow speed, crafting rules, and so on. Some mod authors add sync support (ServerSync, Jötunn), many don't. ServerConfigSync does it for all of them, with nothing to change in the mods themselves.

How it works

• The server is the source of truth. When a player joins, the server sends the values from its own BepInEx config files.
• The player's game applies them in memory only. The player's .cfg files are never overwritten, and their own values come back as soon as they disconnect. Playing on several servers, or single player, is unaffected.
• Mods are notified through the normal BepInEx SettingChanged event, so mods that react to setting changes pick up the server's values immediately.
• If the admin edits a .cfg file while the server is running, the new values are pushed to connected players (can be turned off).

Installation

Install it on the server and on every player's game (with r2modman, Gale or Thunderstore Mod Manager, or by copying ServerConfigSync.dll into BepInEx/plugins).

Players without the mod can still join, they just keep their own settings, unless the server sets RequireClientMod = true.

Configuration

The settings are in BepInEx/config/Manke.ServerConfigSync.cfg. The server only reads the Server section and players only read the Client section.

Server

Setting	Default	Description
Enabled	true	Send the server's settings to players who join.
SyncMode	All	All: every mod. Whitelist: only the mods in PluginList. Blacklist: every mod except those in PluginList.
PluginList	(empty)	Comma-separated plugin GUIDs for Whitelist/Blacklist. A mod's GUID is written at the top of its .cfg file.
ExcludedEntries	(empty)	Comma-separated entries that are never synced: GUID, GUID:Section or GUID:Section:Key, with * as a wildcard. Example: ishid4.mods.betterarchery:Bow Zoom:*
SyncKeybinds	false	When off, hotkeys and keyboard shortcuts stay as each player set them.
SkipSelfSyncingMods	true	Skip mods that already sync their settings (with ServerSync, or with their own sync code when it can be recognized) and Jötunn entries marked admin-only.
AllowedSecretEntries	(empty)	Entries that look like secrets are never sent (see below). List here, in the ExcludedEntries format, the ones you really want to send.
RequireClientMod	false	Refuse players who don't have ServerConfigSync.
LiveUpdates	true	Reload a .cfg file edited while the server runs and push the new values to connected players.

When the server starts, its log says how many entries from how many mods will be sent, and which ones were skipped and why.

Client

Setting	Default	Description
AcceptServerConfig	true	Apply the server's settings while connected.
ShowStartupWarning	false	Also show in game which mods might only read their settings at startup (see Limitations). It's a guess, so by default it only goes to the log.
ListAffectedMods	true	Name those mods in that message.

Debug

Setting	Default	Description
VerboseLogging	false	Log every synced entry (old and new value).

What is sent, and what is not

Only config values are sent. No files and no code, nothing else from the server.

Never sent:

• BepInEx.cfg and ServerConfigSync's own settings.
• Entries that look like secrets: a section or key mentioning a webhook, token, password, secret, API key, auth, credential, URL, URI, endpoint or connection string, and any value that is a URL. A Discord webhook in a server-side mod's config never leaves the server. If you really want one of these to be sent, list it in AllowedSecretEntries.
• Keybinds, unless SyncKeybinds is on.
• Mods and entries the admin excluded.

Security on the player's side

• Data is accepted only from the server the player is connected to.
• Only existing entries of mods that are loaded are changed. Nothing is created.
• Transfers are size-limited (compressed and uncompressed), and malformed data is rejected.
• Server values are never written to disk, and nothing is ever executed. If a mod saves its config while you're connected, your own values are what get written.
• If you change a synced setting while connected (for example in a config manager), it's saved as your value, and the server's value stays active until you leave.

Limitations

• Mods that only read their settings at startup (for example, ones that set up items or recipes once when the game loads) won't see values that arrive when you join. ServerConfigSync can't detect this with certainty. It writes in the log which mods with changed values don't listen for setting changes, but many of those work fine anyway because they read the value every time they use it.
• Only the main config file of each mod (<GUID>.cfg) is synced. Extra .cfg files a mod creates itself, and YAML/JSON configs, are not.
• Entries a mod creates only later in the game (after you join) are not synced.
• Some mods sync their settings with their own code that can't always be recognized. Syncing them twice is harmless; to skip one, use SyncMode = Blacklist.

License

MIT. Source code: https://github.com/peppeaiello/ServerConfigSync