The Explorer's Friend

A lightweight, fully server-side browser world map for Fabric, Quilt, NeoForge, Spigot and Paper servers.

Install one JAR on the server — players join with a completely vanilla client and open the live map in their browser. No client mod, no custom network protocol, nothing for players to install. (Putting the JAR into a client instance is harmless: singleplayer worlds get a map through the integrated server.)

Why another web map?

🎨 Mod blocks just work. On startup the mod inventories every installed mod JAR (SHA-256 content identity, nested jar-in-jar included), resolves each registered block through its blockstate → model → texture chain and computes a representative map color from the actual texture — in linear color space, alpha-aware, with outlier trimming. Everything is cached content-addressed: unchanged mods are never scanned twice, and a typical modpack re-scan after adding one mod takes milliseconds.

⚡ Minimal server impact. Nothing heavy ever runs on the server thread. Live world access is limited to hard-budgeted chunk snapshots (default ≤ 1.5 ms and ≤ 4 chunks per tick); full renders read region files from disk on worker threads without loading a single chunk. All queues are bounded with backpressure and job merging, and an MSPT-based auto-throttle pauses background rendering while the server is busy.

🗺️ Complete map features.

• Topographic tiles with relief and water-depth shading, multiple zoom levels, incremental event-driven updates (block changes → debounced re-render)
• Resumable, pausable full renders (/efmap render)
• Claims overlay: auto-detected integrations for FTB Chunks and Open Parties and Claims (official APIs, nothing bundled) plus a JSON import bridge for other systems — semi-transparent fills, team colors, hover details
• Live players with real skin heads (cached, privacy-hardened, vanish-API)
• Markers via /efmap marker ... with a built-in icon library and user-supplied custom icons, plus banner markers: rename a banner in an anvil and place it — it appears on the map with its actual pattern; breaking it removes it
• Waystones layer (Fabric/Quilt/NeoForge, with the Waystones mod): named waystones as their own toggleable layer — sharestones stay private
• Layer panel in the web UI (claims / markers / banners / waystones / players), state persists in the browser

🔒 Safe and private by default. Binds to 127.0.0.1 until you decide otherwise (reverse-proxy guide included). Strict path validation, zip/PNG-bomb limits, bounded connections. Player layer: invisible/spectator filtering, position rounding and delay, name anonymization, per-player opt-out — or turn it off entirely.

📊 Observable. Structured console summaries, /api/v1/status JSON diagnostics and an optional Prometheus /metrics endpoint.

Quick start

1. Pick the file for your platform and Minecraft version (see below) and drop it into mods/ (Fabric/Quilt/NeoForge) or plugins/ (Spigot/Paper). Fabric/Quilt additionally need Fabric API.
2. Start the server → map at http://localhost:8080/.
3. Render the already-explored world: /efmap render minecraft:overworld (Spigot/Paper: /efmap render minecraft_overworld)

On dedicated servers the first start downloads the vanilla client JAR once from Mojang's official servers (block textures are not in the server JAR; SHA-1-verified, cached, can be disabled).

Choosing your file

Every stable Minecraft version from 1.21.1 to 26.2 is covered. Install exactly one Explorer's Friend file matching your platform and version:

Loader minimums (Fabric): ≥0.16 (1.21.1–1.21.8), ≥0.17.0 (1.21.9+), ≥0.17.3 (1.21.11), ≥0.19 (26.x). Fabric API is required on Fabric/Quilt only.

Optional integrations per platform:

• Fabric/Quilt: FTB Chunks (1.21.1, 1.21.11), Open Parties and Claims (all), GOML/Common Protection API, Waystones layer, LuckPerms permission nodes
• NeoForge: FTB Chunks + Open Parties and Claims (1.21.1), OPAC (26.2), Waystones
• Spigot/Paper: GriefPrevention claims
• The JSON claim import works everywhere.

Links

• Source, issues, full documentation (configuration reference, reverse proxy, performance, API): https://github.com/CptGummiball/explorers-friend

• Spigot/Paper Version

License: MIT. Original implementation — no code or assets from other map projects.