Harbour Party

A Captain of Industry mod for trading goods with friends on your local network.

Everyone plays their own island. Run Harbour Party on the same LAN and you find each other automatically - no addresses, no lobbies, no accounts. Each captain lists what they need, everyone sees those lists, and you ship goods across with one click.

What it does technically

• Opens a TCP socket on port 27960 and broadcasts UDP on 27961, both LAN-only
• Nothing leaves your local network: no servers, no telemetry, no accounts
• Peers exchange only product ids and amounts
• All captains must run the same game version and the same version of this mod

Requires the Trade dock research.

Building

Needs Captain of Industry installed. The project finds it automatically in the usual Steam locations, or set COI_ROOT to the game folder.

dotnet build HarbourParty.csproj                        # build
dotnet build HarbourParty.csproj /p:DeployToGame=true   # build and install locally
dotnet build HarbourParty.csproj /p:Package=true        # build a distributable zip

The toolbar icon lives in a Unity asset bundle, rebuilt only when the art changes:

Unity.exe -batchmode -quit -projectPath UnityAssets       -executeMethod HarbourParty.EditorTools.BuildHarbourPartyBundle.Build

Unity must be the same version the game ships (6000.3.19f1) - asset bundles are serialisation-version locked.

HarbourParty.TestPeer is a headless stand-in that speaks the protocol without the game, so the network side can be exercised without launching two copies.

Licence

COI-Open 1.0. You may use, modify and redistribute this within the Captain of Industry ecosystem, provided derivatives stay under the same licence and the original author is credited.

This mod redistributes no game files. It is built against Captain of Industry's assemblies but ships none of them, and grants no rights in any MaFi Games intellectual property. See the modding policy.