Switchy

Switchy allows players to create and switch between player profiles, which save part of their player data.

This is both data-driven and player-customizable. Here's a profile with Styled Nicknames and Fabric Tailor (+SCH):
Support is also built-in (via data) for Lampblack Pronouns, Trinkets/Accessories, Pehkui (width/height), and Origins.

You can even fluently chat using the display names of other profiles, just like PluralKit:
This is fully compatible with well-behaved chat bridges, like our cantilever fork!

Usage

Disclaimer: All mods that manipulate player data have a save corruption risk!
Always take backups of your worlds, especially when updating mods.

Just run /switchy and follow the hints! This covers renaming, toggling components, and making new profiles.

After this, you can freely switch profiles via /switch <name> or by clicking <switch> in the profile list.
Switching into a profile restores component data to the state it was in was when the profile was last used.
So to change e.g. a fabric tailor skin for a profile, switch into the profile first, set the skin, and switch out.

You can use /switchy say to send a chat message as if you were switched into a specific profile.
Use /switchy edit <name> tag <prefix>text<suffix> to match regular chat messages based on a pattern.
Display names look slightly different to styled nicknames/chat, so just adjust their configs to match.

Profiles are per-world, so speed things up by running /switchy export to get your name/skin data to save to a .json file.
To import, upload the file (e.g. to tmpfiles.org) and paste the link into /switchy import all <url>.
You can also import from PK (and import from / export to Utter) - use /switchy import <member/group> to filter imports.

Compatibility

Note: If Switchy crashes your 1.20 modpack, set fastSingleplayerReconnect to false in config/switchy.toml

For compatibility with new mods, components are defined like so:

// data/minecraft/switchy_components/inventory/ender_chest.json (minecraft:inventory/ender_chest)
{
  "enabled": true, // whether to load the component at all. use this instead of deleting default files, as they'll regenerate.
  "codec": "inventory", // which codec (from the registry in SwitchyComponentTypes) to use to deserialize the data. defaults to "nbt" (passthrough)
  "path": "EnderItems", // NBT path targeting the part of player.dat to load from / modify to
  "preview": "inventory", // which text previewer (from the registry in SwitchyComponentTypes) to use in chat. null = toString(), use "trunc" for long data. Start with $ to use an NBT path for passthrough components.
  "prefix": "👁 ", // a prefix to add to the text preview, for glanceability
  "emptyChecker": "inventory", // which empty checker (from the registry in SwitchyComponentTypes) to use to prevent profile deletion for precious data. Start with $ to use an NBT path for passthrough components.
  "group": "inventory", // components with a matching group ID will be previewed and toggled as if they're one component
  "default": [], // default value. JSON serialized. set to "$copy" to copy the value from previous. set to null or omit to delete the key from player data as the initial value.
  "hidden": false // hides the component preview in the profiles list (still shown in the components list)
}

Feel free to PR components (and previewers/etc with no dependencies) into the main mod - see existing examples.

Switching data outside player NBT requires an addon. API TBD - Interested addon devs can hit up the issues page.

Afterword

If you're a plural system (or a friend to one) and appreciate our work, please consider reading and sharing sys.guide, our plurality handbook.

Switchy was our first original minecraft mod, made during the mod jam ModFest: Singularity.
Since making it, the minecraft modding community has given us friendship, mentorship,
endless favours, an outlet for self-expression, and reinforced our passion for software as an art.
Everyone who's been a part of that - and you should know who you are - thank you.