A Paper plugin that adds a toggleable "Nether Portals" layer to BlueMap
BlueMapPortalMarkers
See every Nether portal on your BlueMap web map โ automatically.
BlueMapPortalMarkers adds a toggleable Nether Portals layer to BlueMap and keeps it in sync with your world. Portals appear the moment they're lit, get discovered as players explore, and disappear when broken โ and the whole layer survives server restarts. No commands to memorise, no manual marker editing, no spreadsheet of coordinates.
โจ Features
- ๐ต A live "Nether Portals" layer in BlueMap. Every portal becomes a clickable marker. Players toggle the whole layer on or off from BlueMap's marker menu.
- โก Automatic detection. Portals are picked up four ways, all merged into one clean list:
- New portals appear instantly when a frame is lit or created by nether-pairing.
- Existing portals are found by a startup sweep around spawn and online players.
- Roaming coverage quietly fills in portals as players explore new chunks.
- Broken portals are removed automatically when their blocks are destroyed.
- ๐งญ Portal linking (Overworld โ Nether). Each popup shows the predicted counterpart in the other dimension using the vanilla 8:1 rule โ and when that counterpart is already on the map, a "Go to linked portal" button flies the viewer straight to it.
- ๐ No duplicates, ever. However many times a portal is detected, it shows up as exactly one marker โ frames of any size are handled correctly.
- ๐พ Persists across restarts. Discovered portals are saved to disk and re-drawn automatically whenever BlueMap reloads.
- ๐ ๏ธ Admin commands. Force a sweep, view per-world portal counts, purge stale markers, and hot-reload settings without restarting the server.
- ๐๏ธ Highly configurable. Per-world filtering, custom marker icon and label, visibility distance, optional background sweeping, and more โ most of it applied live with
/bmportals reload. - ๐ชถ Lightweight. Detection rides on data Minecraft already tracks, so it stays cheap even on busy servers.
๐ Requirements
| Server | Paper 26.1+ (the detection API isn't available on Spigot or older Paper) |
| Java | 25+ runtime |
| Required plugin | BlueMap installed and enabled |
๐ Quick start
- Download the latest
BlueMapPortalMarkers-<version>.jar. - Drop it into your server's
plugins/folder, alongside BlueMap. - Restart the server โ a config file is created on first run.
- Open BlueMap and toggle the Nether Portals layer in the marker menu. Done!
Existing portals near spawn show up on the first sweep; the rest appear as players roam, or you can run /bmportals sweep to scan immediately.
โ๏ธ Configuration highlights
Everything lives in plugins/BlueMapPortalMarkers/config.yml. A few favourites:
markers.label/markers.iconโ rename the layer and give it a custom icon.discovery.sweep-radiusโ how far the startup sweep reaches around spawn and players.discovery.worldsโ whitelist or blacklist worlds (skip creative or minigame worlds).linking.enabledโ turn the OverworldโNether predicted-link section on or off.discovery.background-sweepโ opt-in periodic re-sweeping for always-fresh coverage.
๐ก The clickable "Go to linked portal" deep-link needs a one-time BlueMap web-app tweak (two small files BlueMap ships in the box). Everything else โ markers, popups, predicted-link text โ works with zero web setup. See the README for the 3-step guide.
๐ฎ Commands
All /bmportals subcommands require the bmportals.admin permission (ops by default).
| Command | What it does |
|---|---|
/bmportals reload |
Re-read the config and apply it live |
/bmportals sweep [radius] |
Scan around every spawn + online player |
/bmportals sweep me | <player> | <x> <z> |
Scan a specific spot |
/bmportals stats |
Total and per-world portal counts |
/bmportals purge [world] |
Clear stored portals (e.g. after WorldEdit removals) |
โ ๏ธ Good to know
- Paper 26.1.2+ only โ there's no Spigot or older-Paper fallback.
- Portals in never-touched pre-1.14 regions may not appear until those chunks are loaded by the game.
- The startup sweep covers a radius around spawn and players, not the entire world โ roaming coverage and background sweeping fill in the rest over time.
๐ Privacy
Ships with anonymous, aggregate usage stats via bStats (metrics.enabled in the config, or opt out server-wide). No personal or world data is ever collected.
๐ Open source
BlueMapPortalMarkers is free software under the GNU GPL v3.0. Source, issues, and releases live on GitHub.