As the name might suggest, Silksong Multiplayer (SSMP) is a multiplayer mod for the popular 2D action-adventure game Hollow Knight: Silksong. The main purpose of this mod is to allow people to host games and let others join them in their adventures. There is a dedicated Discord server for the mod where you can ask questions or generally talk about the mod. Moreover, you can leave suggestions or bug reports. The latest announcements will be posted there.
When using an installer that is compatible with Thunderstore, everything should work auto-magically.
SSMP works with the BepInExPack for Silksong found on the Silksong Thunderstore community. Follow the instructions for the BepInExPack on Thunderstore and once completed, do the following:
- Make a new directory named
SSMPin the BepInEx plugins folder found:path\to\Hollow Knight Silksong\BepInEx\plugins\ - Unzip the
SSMP.zipfile from the releases into this new directory- Make sure that all
.dllfiles are in theSSMPdirectory without any additional directories
- Make sure that all
The mod can be accessed by using the "Start Multiplayer" option in the main menu of the game. Once the multiplayer menu is opened, you will be greeted with a dashboard from which you can choose to play online or on a local network.
SSMP fully supports Steam networking. This means you can easily host a game and invite your friends through the Steam overlay without worrying about port forwarding or IP addresses.
- Hosting: To host a Steam lobby, simply select the "Steam" option in the hosting menu.
- Inviting: Once hosting, you can use the Steam overlay to invite friends, or use the
/invitecommand in-game. - Joining: Friends can join your game directly through their Friends list or by accepting your invite.
The mod includes a built-in server browser powered by our Matchmaking Service.
- Lobby Browser: You can browse public lobbies directly from the multiplayer menu.
- Hole Punching: The MMS facilitates NAT hole-punching, which allows players to connect to each other directly (P2P) without needing to port forward in most cases.
For those who prefer a traditional connection, you can still connect directly via IP address.
- Hosting: Forward the port (default
26960) on your router to your device. - LAN: Playing on the same local network works out of the box.
- VPN: Tools like Hamachi can be used to simulate a LAN over the internet.
If you start hosting or joining a server, the mod will prompt you to select a save file to use. This save file is only used locally and will not synchronise with the server.
The mod features a chat window that allows users to enter commands.
The chat input can be opened with a key-bind (Y by default), which features the following commands:
/help: Show the list of available commands./list: List the names of the currently connected players./inviteor/inv: Open Steam's invite dialog to invite friends to your lobby./addon <enable|disable|list> [addon(s)]: Enable, disable, or list client addons./set <setting name> [value]: Read or write a setting with the given name and value./skin <skin ID>: Change the currently used skin ID for the player./team <None|Moss|Hive|Grimm|Lifeblood>: Change the team that the player is on./announce <message>: Broadcast a chat message to all connected players (Admin only)./kick <auth key|username|ip address>: Kick a player (Admin only)./ban <auth key|username>: Ban a player (Admin only)./unban <auth key>: Unban a player (Admin only)./banip <auth key|username|ip address>: Ban an IP address (Admin only)./unbanip <ip address>: Unban an IP address (Admin only)./copysave <from> <to>: Copy save data from one player to another (Currently disabled)./debug: Output various debug information to the log.
Each user will locally generate an auth key for authentication and authorization. This key can be used to whitelist and authorize specific users to allow them to join the server or execute commands that require higher permission.
/whitelist [args]: Manage the whitelist with following options:on|off: Enable/disable the whitelist.add|remove [name|auth key]: Add/remove a user.clear [prelist]: Clear the whitelist.
/auth <name|auth key>: Authorize a player./deauth <name|auth key>: De-authorize a player.
It is possible to run a standalone server on Windows, Linux and Mac. The latest executable of the server can be found on the releases page. Make sure to download the correct version for your OS.
The standalone server can be run using .NET 9.0. If you are only concerned with running it, then download the latest .NET 9.0 runtime.
After installing the .NET runtime, the executable can be run from a terminal using ./SSMPServer [port].
The port argument is optional and defaults to 26960 if omitted.
The server will read/create a console settings file called consolesettings.json, which can be changed to alter the default startup settings of the server.
This includes which port to default to if omitted on the command line.
The other setting in this file (fullSynchronisation) is currently unused.
The server will also read/create a server settings file called serversettings.json, which can be changed to control the server settings as listed in the following section.
Alternatively, settings can be changed by running the settings command on the command line.
In addition to the commands described above, the standalone server also has the following commands:
exit: Will gracefully exit the server and disconnect its users.log [log level(s)]: Adjusts which log messages are output to the console.
There are a lot of configurable settings that can change how the mod functions.
The values below can be read and modified by the /set command described above.
All names for the settings are case-insensitive, but are written in case for clarity.
IsPvpEnabled: whether player vs. player damage is enabled.- Aliases:
pvp
- Aliases:
AlwaysShowMapIcons: whether player's map locations are always shared on the in-game map.- Aliases:
globalmapicons
- Aliases:
OnlyBroadcastMapIconWithWaywardCompass: whether a player's map location is only shared when they have the Wayward Compass charm equipped. Note that if map locations are always shared, this setting has no effect.- Aliases:
compassicon,compassicons,waywardicon,waywardicons
- Aliases:
DisplayNames: Whether overhead names should be displayed.- Aliases:
names
- Aliases:
TeamsEnabled: Whether player teams are enabled. Players on the same team cannot damage each other. Teams can be selected from the client settings menu.- Aliases:
teams
- Aliases:
AllowSkins: Whether player skins are allowed. If disabled, players will not be able to use a skin locally, nor will it be transmitted to other players.- Aliases:
skins
- Aliases:
The system for skins is currently not implemented entirely. While it is possible to change skin IDs using the command system, it will most likely not work correctly.
There are a few ways you can contribute to this project, which are all outlined below. Please also read and adhere to the contributing guide.
If you have any suggestions or bug reports, please leave them at the issues page. Make sure to label the issues correctly and provide a proper explanation. Suggestions or feature requests can be labeled with "Enhancement", bug reports with "Bug", etc.
If you like this project and are interested in its development, consider becoming a supporter on Patreon. You will get access to development posts, sneak peeks and early access to new features. Additionally, you'll receive a role in the Discord server with access to exclusive channels.
HKMP is a game modification for Hollow Knight that adds multiplayer.
Copyright (C) 2026 Extremelyd1
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