Journeymap Additions
If you have spent any real time underground in Minecraft, you know the pain of hunting slime chunks. You dig endless tunnels, light up cavern after cavern, and still watch the wrong mobs spawn. Journeymap Additions exists to fix exactly that problem. This lightweight companion mod plugs into the popular Journeymap minimap and overlays the chunks where slimes can actually spawn, saving you hours of guesswork. It also doubles as a reference implementation for the Journeymap API, which makes it a favorite among add-on developers.
What Journeymap Additions Actually Does
At its core, this add-on is a visual helper. Once installed alongside Journeymap, it marks every locally loaded chunk that qualifies as a slime chunk directly on your minimap and full-screen map. Instead of memorizing coordinates or running external seed tools, you get the information in real time as you explore. The overlay updates as chunks load, so the map stays accurate while you branch mine or build a farm.
The secondary purpose is just as important for the modding community. Journeymap Additions is built to demonstrate how the Journeymap API works in practice. Developers who want to create their own overlays, waypoint tools, or map layers can study this project as a working example. That makes it both a practical utility and a learning resource.
Current Features at a Glance
- Highlights slime chunks on locally loaded chunks in real time
- Integrates directly with the Journeymap minimap and full-screen map
- Serves as a sample add-on built on the Journeymap API
- Lightweight and designed to stay out of the way of your normal gameplay
Version Support and Mod Loaders
Journeymap Additions is maintained for modern Minecraft releases, with builds targeting the 1.16 through 1.20 era of the game depending on the loader. The mod is distributed for Forge and NeoForge, and Fabric support depends on the specific release you grab. Because it depends on Journeymap itself, always match the add-on version to your Journeymap version and your Minecraft version. Mismatched builds are the most common cause of crashes or missing overlays.
If you use a launcher that manages dependencies for you, this becomes far less painful. The foxygame.net launcher, for example, keeps Journeymap Additions and its parent mod in sync automatically, so you never have to manually hunt for the right build. That kind of automatic version matching removes the guesswork that usually comes with modded Minecraft setups.
Multiplayer Notes You Should Not Ignore
Here is the detail that trips up a lot of players: Journeymap Additions needs to be installed on the server if you are playing multiplayer. The slime chunk data has to come from the server side to render correctly for every player. If only the client has the mod, you may see nothing at all, or the overlay may behave inconsistently between players. On singleplayer worlds this is a non-issue, since your client is the server.
Known Issues
There is one documented visual quirk worth mentioning. The minimap can render the player arrow strangely while the add-on is active. This is a Journeymap-side issue rather than a problem with the add-on itself, and it is expected to be addressed in a future Journeymap release. It does not affect gameplay, only the appearance of the arrow on the map.
How to Install Journeymap Additions
Getting the mod running is straightforward if you follow the order of operations:
- Confirm your Minecraft version and your mod loader, then download Journeymap Additions for that exact combination.
- Install Journeymap first, since the add-on will not load without it.
- Drop both mod files into your mods folder.
- Launch the game and check that the slime chunk overlay appears on loaded chunks.
- For multiplayer, repeat the installation on the server side.
If you want to skip manual file management entirely, a launcher with a built-in add-on catalog can handle the whole process in one click. The foxygame.net launcher lists Journeymap Additions alongside compatible Journeymap builds, which means the correct versions are selected for you before anything is downloaded.
Final Thoughts
Journeymap Additions is a small mod with a very specific job, and it does that job well. For survival players, it turns the tedious search for slime chunks into a glance at the map. For developers, it offers a clean, working example of the Journeymap API in action. Just remember the two rules: match your versions, and install it on the server for multiplayer. Do that, and your minimap becomes a genuinely useful planning tool rather than just a pretty overlay.