Privacy: what the mod sends and reads

The mod runs on your computer only. It talks to two MC Planner servers, reads a few kinds of files, and sends nothing else. No analytics.

Who it talks to

Server	When	What it sends
auth.lab43.dev	When you sign in	A request for a sign-in code, with a device name like "Minecraft 26.2 · Windows" so you recognise it in your account
app.mc-planner.com	While you're signed in	Your sign-in key, and the mod and Minecraft version

What happens on app.mc-planner.com:

Your account: your name and colour, and whether you have an active plan (when you sign in, every now and then while you play, and when you open a plan file).
Your shared worlds: the list, and the plan of the one you picked. Every 10 seconds while you're in a world with the overlay or the HUD on, it asks whether anything changed. Usually the answer is "no" and nothing more is sent.
Your changes: a status you set, or a marker you add (its name and where you stand: x, y, z and the dimension). Your friends see them in the app.

Your password and email never reach the mod. It signs in with a code (see Sign in with a code) and gets its own key, which only works for the mod.

It only reads these files. It never uploads them.

Plan files (.mcplan, and older .json exports) in Documents\MC Planner and in the profile's mcplanner/plans folder.
Schematic files, to show a schematic building's blocks. To find the one that matches the plan's fingerprint, it reads the schematic files (.litematic, .schem, .nbt, .schematic) in the profile's schematics folder, your Downloads, your Desktop and Documents\MC Planner (on Windows with OneDrive, also OneDrive's Desktop and Documents\MC Planner).
Your world, as the game shows it: the height of the ground, to draw the plan on the terrain, and the blocks you've built, to hide finished ghost blocks. That's the game's own data on your computer.

File	What's in it
`.lab43/mcplanner-minecraft.json` in your user folder	Your sign-in key. Kept outside the Minecraft folder, so a shared modpack doesn't have it. (If the user folder can't be written to: `config/mcplanner-auth.json` in the profile.)
`config/mcplanner.json` in the profile	Your display settings and which plan you picked for each save and server
`mcplanner/cache/` in the profile	The last copy of each shared world's plan, so it works offline
`mcplanner/plans/` in the profile	Plan files you dropped onto the window

J → Sign out disconnects this computer and deletes the key from it.
On auth.lab43.dev/account → Connected devices you can disconnect it from anywhere.

The mod is licensed under AGPL-3.0. Its public code repository is coming with the Modrinth release. Also see MC Planner's privacy policy.