Active Worlds is a live, crowdsourced list of Palia worlds and the events happening in them right now — such as Flow Trees and Palium — powered by players running the free TH.GL companion app. You can browse it at palia.th.gl/worlds.
Palia streams each zone as its own server instance, and to hop into a specific world you need its 4-character join code. On the tracker you can request a code for any active world.
"A player wants to join your world" prompt: when someone requests a code for the world you're currently in, the app shows you a prompt. Sharing is opt-in and explicit — nothing happens unless you open the game menu (Esc → World Code). When you do, the app reads the code the game displays and posts it to the tracker.
What sharing does — please read: posting the code lists it publicly on the tracker, and anyone with the code can join the world you're currently in (joining costs them a teleport cooldown or a teleport potion, so it isn't instant server-hopping). Only share if you're happy for others to hop in — e.g. don't share during a private or player-hosted event. The code also expires on Palia's side, so a shared code goes stale on its own.
Don't want any of this? Turn off Settings → Palia → Join-code request notifications. That's a true opt-out: you'll stop seeing the prompts and the app will never share your world's join code while it's off. If you'd already shared a code before turning it off, the tracker drops it within a few minutes once the app stops sending it.