Friends on LAN

One Pip, on the computer that runs her: her AI, her voice, her memory and her heart. Open your world to LAN and friends on the same network join on the same Minecraft version (release 1.21.1).

How it works

Friends with the mod ("light mode") see her exactly as you do: her skin, face, moods, gestures and subtitles, drawn by their own game from what yours sends. They need no AI, Python or keys. Her voice plays from the host's computer.
Friends without the mod see a stand-in the plain game can draw (a small Allay named after her that follows where she floats) and talk to her in chat the same way.
Everyone talks to her in chat, starting with her name: Pip, can you give me night vision? She answers as [Pip] ..., knows who said what, and sees them in the world. A friend's talk key opens the chat with her name already typed.

Set up a friend's Windows PC

Your friend needs Minecraft Java Edition, on the same Wi-Fi or home network as you, and two small mod files. Nothing else.

Get Minecraft 1.21.1 once. In the Minecraft Launcher: Installations → New installation → version release 1.21.1 → Create → Play, then quit the game.
Install Fabric. Download the Fabric installer for Windows from fabricmc.net, run it: tab Client, Minecraft 1.21.1, the newest loader, "Create profile" ticked, then Install. The launcher now has a fabric-loader-1.21.1 installation.
Add the two mods to the mods folder: press Win + R, type %APPDATA%\.minecraft\mods and press Enter (create the mods folder if it's missing).
- Fabric API for 1.21.1 (a file named fabric-api-0.116.x+1.21.1.jar) from Modrinth.
- The Kindred Spirit jar (the one without -sources in its name): the host can send theirs, or your friend builds it from the repository (below).
Join. The host opens their world: Esc → Open to LAN → Start LAN World. Your friend starts the fabric-loader-1.21.1 installation, goes to Multiplayer, and the world appears at the bottom as a LAN world after a few seconds. If it doesn't: Direct Connection with the host's local address and the port shown in the host's chat (for example 192.168.1.20:52143).

Building the mod on Windows

Install Java 21 (Eclipse Temurin JDK 21, the Windows .msi), clone the repository, then in PowerShell:

git pull
cd mod
.\gradlew.bat build

Copy mod\build\libs\kindred-spirit-<version>+1.21.1.jar into the mods folder. The first build downloads Gradle and Minecraft's files, so it takes a few minutes.

Staying up to date: Update Pip

A friend's Kindred jar must be the same version as the host's. Whenever the host updates, the friend updates too, with Minecraft closed. With the repository cloned, one double-click does it all: get the latest version, build the mod, replace the jar in the mods folder, and fetch Fabric API if it's missing.

Double-click scripts\update-pip-windows.cmd (a desktop shortcut to it is handy), or
in PowerShell: powershell -ExecutionPolicy Bypass -File scripts\update-pip-windows.ps1

What the host decides

Who she stays with: "Pip, stay with Robin" or /kindred follow robin; /kindred follow me brings her back.
Whether friends may ask for her powers (lanGuestPowers, on by default): gifts, effects like haste or night vision, healing, finding, leading and protecting, within her power and style. Off, they only talk with her.
"From now on, do what Robin says" lets that friend ask her to follow them or stay.
lanGuests: false turns all of it off.

A heart for each friend. She has feelings for each of them too, moved by how they treat her and kept across sessions: warm with the kind one, prickly with the one who's mean. If a friend hurts her in front of you, she notices whether you stand up for her.

When a friend hosts the world instead

Your Pip comes with you (her brain stays on your computer). If their game has the mod, it shows her to everyone, passes their "Pip, ..." chat to your Pip, and carries out her powers in their world for you. Without the mod on their side she's only with you: she talks, sees, finds and leads, but can't change their world.

Settings for friends

In %APPDATA%\.minecraft\config\kindredspirit.json (created after the first start):

Setting	What it does
`"sharedPip": "host"`	default: in a friend's world, see and share their Pip
`"sharedPip": "own"`	your own Pip instead (that needs the whole setup, AI key and all)
`"lanVisitors": true`	default: when you host, a friend's Pip may use her powers in your world. `false` says no

If something's wrong

"Incompatible" or "outdated client": you're not on 1.21.1. Start the fabric-loader-1.21.1 installation.
The game crashes at start: Fabric API is missing or for the wrong version (it must say +1.21.1), or there are mods for another version in mods.
You see a small blue Allay named Pip instead of her: your game doesn't have the mod, or not the same version as the host's. Check the mods folder, or run Update Pip.
She doesn't answer: start your message with her name ("Pip, ..."); the host's brain must be running.