MONx

A monster editor for OpenTibia servers — Ironcore, TheForgottenServer, TheVioletProject, Nostalrius, Canary/OTServBR, CrystalServer and BlackTek. Open a workspace, pick a monster, edit, save.

A workspace is up to four folders: the server's monster/ folder, its items/ folder, a client folder and optionally spells/. Only the monsters folder is required — the rest fill in what they can. Outfits, corpses and loot render as real sprites because the client assets are loaded alongside the monsters, from either a .spr/.dat pair or a modern 12.x+ asset bundle.

Built with Tauri 2 (Rust) and React 18 + TypeScript + Vite.

Prerequisites

• Rust (stable) — via rustup
• Bun 1.3+ — via bun.sh (the repo pins bun@1.3.14)

Arch Linux

sudo pacman -S --needed base-devel webkit2gtk-4.1 curl wget file openssl \
  gtk3 libappindicator-gtk3 librsvg

Ubuntu 22.04+ / Debian (older releases ship only webkit2gtk 4.0, which Tauri 2 does not support)

sudo apt install libwebkit2gtk-4.1-dev build-essential curl wget file \
  libxdo-dev libssl-dev libayatana-appindicator3-dev librsvg2-dev

Development

bun install
bun run tauri:dev

On Linux use ./monx.sh instead — same thing, but through XWayland with WebKitGTK's dmabuf renderer disabled, which otherwise crashes the webview under Wayland ("Error 71 Protocol error").

Release builds

On Windows:

bun run tauri:build:portable   # portable .exe only
bun run tauri:build            # NSIS installer only
bun run tauri:build:all        # both

• Portable: src-tauri/target/release/monx-portable.exe
• Installer: src-tauri/target/release/bundle/nsis/

The bundle target in tauri.conf.json is Windows NSIS, so on Linux build the plain binary instead:

bun run build                      # frontend into dist/
cd src-tauri && cargo build --release

It lands at src-tauri/target/release/monx. Build the frontend first — the release binary embeds dist/ at compile time, so a stale dist/ ships stale UI. Under Wayland, launch it the same way monx.sh does:

GDK_BACKEND=x11 WEBKIT_DISABLE_DMABUF_RENDERER=1 ./src-tauri/target/release/monx

Verifying changes

• Frontend: bun run build (runs tsc, then Vite)
• Backend compile: cargo check in src-tauri/
• Backend behaviour: from src-tauri/, cargo run --example probe_monster -- <monsters-dir> reads and rewrites the whole corpus and diffs the bytes. probe_dat, probe_assets and probe_lua do the same for sprite composition and the Lua document layer. AGENTS.md lists the flags.

Further reading

• AGENTS.md — architecture, conventions, directory map
• ENGINES.md — how the seven servers differ, and the profile system that models it
• CONTRIBUTING.md — how to get set up and send a change

Credits

MONx is a fork of SPRx, a sprite browser for the same client formats, and inherits its sprite/thing engine — spr.rs, dat.rs, the protocol image server and the virtualized browsers. SPRx in turn took part of its .spr parser from Sprite Forge by Frenvius, which is MIT-licensed; that notice is retained in LICENSE.

Legal

MONx is an unofficial, fan-made tool. It is not affiliated with, endorsed by, or sponsored by CipSoft GmbH. Tibia is a registered trademark of CipSoft GmbH.

MONx ships no game data. It reads the client and server files you already have — no client assets, item databases or monster files are distributed with it.

Sponsor

MONx is free and MIT-licensed. If it saves you time, you can support the work through GitHub Sponsors.