Community-made multiplayer is already available for Hollow Knight: Silksong through two early mods. SilklessCoop focuses on lightweight co‑op that lets players see each other in-game, with either Steam peer‑to‑peer or a small standalone server. A separate Steam‑only mod adds simple room-based sessions with a basic PvP toggle. Both are proofs of concept: expect desyncs, animation quirks, and limited combat sync.

What these mods offer today

  • See friends’ characters moving around your world while you play your own save.
  • Two connection styles with SilklessCoop: Steam P2P or a small server (VPN or port‑forwarding supported).
  • A Steam‑only option with room invites from the main menu and a basic PvP switch.

Limitations to anticipate: some attacks may look odd on remote players, disconnect/reconnect can leave temporary duplicates until you change scenes, and audio is not synchronized. Boss co‑op is not guaranteed to work reliably yet.

Before you start

  • Install the Unity mod loader BepInEx 5 (the mods were tested on 5.4.23.3). Extract into the game’s root folder.
  • Back up your saves before modding.

Option A: SilklessCoop (Steam P2P or standalone server)

SilklessCoop is an early co‑op mod that prioritizes “you can see each other” functionality. Download it from the project’s release page.

Quick start with Steam P2P (simplest)

  • Install BepInEx 5, then download and extract SilklessCoop into the Silksong root folder.
  • Optionally tune settings in BepInEx/config/SilklessCoop.cfg (mode, server details, hotkeys).
  • Launch the game, load your save, and press F5 to enable multiplayer.
  • On Steam, have one player use the platform’s friend UI to join the other player’s game (both players must have valid Steam copies).
Tip: If you don’t see each other, open BepInEx/LogOutput.txt and check for errors.

Use a standalone server (non‑Steam or mixed setups)

For players without Steam or when P2P is unreliable, SilklessCoop can relay movement through a small server. The author provides a minimal server utility on GitHub: repository.

  • Download or build the server from the repository and run it on a host machine.
  • In BepInEx/config/SilklessCoop.cfg, set mode to standalone and point server IP/port to the host.

Common hosting patterns:

  • Local host + VPN (Hamachi/Radmin): Host uses 127.0.0.1 as server IP; peers use the host’s VPN IPv4.
  • Dedicated server: Run on a separate machine with a public IP; all players set server IP to that address.
  • Local host + port forwarding: Forward the chosen port (default below) on the host’s router; peers use the host’s public IP.
Default port: 45565
Disable local “mirror” (seeing yourself): start the server with --no-mirror
Example:
  echoserver --port 45565 --no-mirror

Option B: Steam‑only multiplayer with basic PvP

A separate mod enables Steam room invites and a simple PvP toggle. Installation is straightforward and currently limited to the official Steam version of the game.

  • Extract the mod’s files into the Silksong root directory (ensure files merge into the existing folder structure, not nested inside an extra folder).
  • All players open the main menu; the host selects “Create Room” then “Invite Players.”
  • After invite confirmations, each player loads their own save to appear together.
  • Configure PvP via Hollow Knight Silksong/BepInEx/config/com.XvX.cfg.

Map sync behavior is basic: positions refresh when a player opens the map. If a marker doesn’t appear, reopen the map or keep it open briefly to update.

Troubleshooting and known issues

  • No one appears: verify BepInEx is loading (plugins listed in BepInEx/LogOutput.txt), confirm both players enabled the mod (e.g., F5 in SilklessCoop), and ensure both are on compatible versions.
  • Standalone server won’t connect: confirm the correct server IP/port in the client config, check that the port (default 45565) is open/forwarded, and test connectivity across your VPN or public IP.
  • Duplicate or frozen players after disconnects: change scenes to clear them.
  • Animations or audio feel off: this is expected at this stage; combat and sound are not perfectly synchronized.

What to expect next

SilklessCoop’s roadmap mentions incremental fixes, better sound sync, basic on‑screen indicators (e.g., arrows to other players), connection status display, and potential public servers. The Steam‑only mod is iterating on map sync and PvP toggles.

Notes on safety and saves

  • Back up your save files before testing any mod.
  • Only play with people you trust; avoid exposing open ports without basic network hygiene.
  • If something breaks, remove the mod files you added and verify game files before relaunching.