[Release] L2J Interlude Toolkit — Headless Python Client, Geodata Scanner & Dashboard

mibanux · 02/09/2026, 17:17

L2J Interlude Toolkit

Headless Python Client · Multi-Agent Geodata Scanner · Web Dashboard · Server Management

No Windows. No Game Client. Just Python + Your L2J Server.

Hey everyone,

I've been deep in the L2J rabbit hole for a while now, building tools that I always wished existed. Today I'm releasing everything as open source. This is a complete developer toolkit for L2J Mobius C6 Interlude — and the centerpiece is something I haven't seen anyone do before:

A fully functional headless Lineage 2 client written in pure Python.

No Wine. No VM. No Windows client install. Runs on macOS, Linux, anything with Python 3. Connects to your login server, authenticates, enters the game world, creates characters, executes admin commands — all from the terminal.

━━━ What's Inside ━━━

① Headless L2 Client (Python)

The real deal — not a simple socket wrapper. Full protocol implementation:

• Complete login flow: BlowfishKey init → RSA authentication → server list → PlayOk
• GameCrypt XOR cipher (encrypt + decrypt game traffic)
• Character creation from code — pick class, name, appearance
• CreatureSay packet parsing (server → client text messages)
• Admin command execution via SendBypassBuildCmd (opcode 0x5b)
• Auto-reconnect with error handling

If you've ever wanted to automate anything on L2J without touching the game client, this is your starting point.

② Multi-Agent Terrain Scanner

Deploy 20+ headless bots simultaneously, each in its own thread with its own game connection. They scan the entire world's geodata in parallel.

• Custom AdminTerrainScan server command — queries GeoEngine directly, returns base64-encoded height + NSWE data in batches of 256 blocks per packet
• Custom AdminGeoExport — full-fidelity .l2d export using native ABlock.saveBlock() (bit-perfect output)
• All 139 regions scanned in ~2 minutes with 20 agents
• SQLite persistence — resume interrupted scans
• 9.1 million cells scanned per run

The traditional approach (teleport + read Z) doesn't work because L2J's teleToLocation does z += 5 without consulting GeoEngine. Our approach queries GeoEngine directly via custom admin commands — actual ground truth data.

③ Real-Time Web Dashboard

Flask-based web UI with Server-Sent Events for live progress:

• World map grid — 11×16 region grid, color-coded: gray=pending, blue+pulse=scanning, green=done, red=error
• Worker table — per-agent status, current region, cells/sec, errors
• Live controls — start/stop, dynamic worker count, scan mode
• Event log — scrolling real-time log with timestamps

Code:

http://localhost:5556 → Terrain Scanner Dashboard
http://localhost:5555 → Geodata Editor

④ Geodata Editor (Web UI)

Visual geodata browser and editor right in your browser:

• L2D binary format parser (flat, complex, multilayer blocks)
• Render modes: heightmap, NSWE flags, block types, combined, cell detail
• Edit individual cells, unblock paths, export renders as PNG
• World coord ↔ geo coord conversion
• CLI tool for batch operations

⑤ Server Management CLI

One script to manage everything. No more hunting through config files:

Code:

./l2j-manage.sh start           # Start MariaDB → Login → Game
./l2j-manage.sh set-rates 5     # All rates to 5x
./l2j-manage.sh gm admin        # Promote to GM
./l2j-manage.sh db-backup       # Backup database
./l2j-manage.sh rebuild         # Recompile Java + deploy JARs
./l2j-manage.sh info            # Show full server config summary

⑥ Bootstrap Automation

Mass-create accounts, characters, and promote to GM in one command:

Code:

./terrain-scanner.sh --bootstrap --num 20 --promote

Creates 20 accounts, 20 characters (Human Fighter), promotes all to GM via MariaDB. Uses AutoCreateAccounts — no manual registration needed.

━━━ How It Works ━━━

Code:

Scanner Worker                    L2J Game Server
     |                                  |
     |  SendBypassBuildCmd              |
     |  "scan_geo 20 18 0"             |
     | ---------------------------->   |
     |                                  |  GeoEngine.getHeightNearest()
     |                                  |  GeoEngine.getNsweNearest()
     |                                  |  x 256 blocks
     |  CreatureSay                     |
     |  "GEODATA|20|18|0|<base64>"     |
     | <----------------------------   |
     |                                  |
     |  (decode -> height + NSWE)       |
     |  (repeat for blockY 0..255)      |
     |  (write .l2d file)               |

Each region = 256 commands. 20 agents running in parallel = entire world scanned in ~2 minutes.

━━━ Tech Stack ━━━

Code:

Game Server      ->  Java 21, L2J Mobius C6 Interlude
Headless Client  ->  Python 3, raw sockets, Blowfish/RSA
Web Dashboards   ->  Flask, Server-Sent Events, vanilla JS
Geodata Render   ->  NumPy, Pillow
Database         ->  MariaDB
Build System     ->  Apache Ant

━━━ Looking for Contributors ━━━

This is just the beginning. Some areas where the community can help:

• Movement-based geodata probing — walk characters in all directions to detect actual walls/cliffs
• Pathnode generation — generate pathnode files from geodata for NPC pathfinding
• Client data extraction — parse official L2 client files for terrain data
• 3D terrain viewer — WebGL-based viewer for the dashboard
• More packet types — expand the headless client protocol coverage
• Other chronicles — port the headless client to High Five, Classic, etc.

Whether you're a Java dev, Python dev, or just into L2J tinkering — there's something to work on.

━━━ Quick Start ━━━

Prerequisites: Java 21, MariaDB, Python 3, Flask, Apache Ant

Code:

pip install flask numpy pillow

Step 1 — Clone and setup database

Code:

git clone https://github.com/elberacasa/l2j-interlude-toolkit.git
cd l2j-interlude-toolkit

brew services start mariadb          # or: systemctl start mariadb
./l2j-manage.sh db-reset             # creates DB + imports all schemas

Step 2 — Start your server

Code:

./l2j-manage.sh start                # starts MariaDB -> Login -> Game
./l2j-manage.sh status               # verify everything is running

Step 3 — Launch the Geodata Editor
Browse and edit geodata visually — heightmaps, NSWE walkability maps, block types. All in your browser.

Code:

./geodata-editor.sh                  # opens http://localhost:5555

• Select any of the 139 regions from the dropdown
• Switch render modes: heightmap (grayscale), NSWE (color-coded directions), block types, combined
• Click cells to edit height and NSWE flags
• Export renders as PNG for documentation or debugging

Step 4 — Run the Terrain Scanner Dashboard
Real-time web dashboard that shows 20+ headless bots scanning the world in parallel with live progress.

Code:

# First time: create 20 bot accounts + characters + promote to GM
./terrain-scanner.sh --bootstrap --num 20 --promote

# Launch the dashboard
./terrain-scanner.sh --dashboard     # opens http://localhost:5556

• Open in your browser
• You'll see the world map grid (11x16 regions), worker table, and event log
• Set worker count (default 20), pick scan mode, click "Start Scan"
• Watch regions go from gray (pending) -> blue with pulse (scanning) -> green (complete)
• Each worker shows: current region, cells scanned, cells/sec, errors
• All 139 regions complete in ~2 minutes — 9.1 million cells

Step 5 — Export geodata
Once scanned, export bit-perfect .l2d files you can drop into any fresh L2J server:

Code:

# In-game as GM:
//geo_export_all                     # exports all 139 regions
//geo_export_all /path/to/output/    # custom output directory
//geo_export 20 18                   # export a single region

Step 6 — Manage your server

Code:

./l2j-manage.sh set-rates 5          # XP/SP/Drop/Adena all at 5x
./l2j-manage.sh gm admin             # promote account to GM
./l2j-manage.sh accounts             # list all accounts
./l2j-manage.sh players              # show online characters
./l2j-manage.sh db-backup            # backup MariaDB
./l2j-manage.sh rebuild              # recompile Java + deploy JARs
./l2j-manage.sh info                 # full config summary
./l2j-manage.sh stop                 # stop everything

━━━ What You Get ━━━

Code:

TWO WEB DASHBOARDS:
  http://localhost:5555  ->  Geodata Editor (browse, render, edit .l2d files)
  http://localhost:5556  ->  Terrain Scanner (live world map, 20+ agents, real-time progress)

SERVER CLI:
  ./l2j-manage.sh        ->  start/stop, rates, GM, accounts, DB, rebuild

SCANNER CLI:
  ./terrain-scanner.sh   ->  bootstrap accounts, launch dashboard, single-agent scan

GEODATA CLI:
  ./geodata-editor.sh    ->  launch visual editor
  python3 tools/geodata/geodata_tool.py info 20_18.l2d     ->  region info
  python3 tools/geodata/geodata_tool.py render 20_18.l2d   ->  render to PNG
  python3 tools/geodata/geodata_tool.py dump 20_18.l2d     ->  dump cell data

CUSTOM ADMIN COMMANDS (in-game as GM):
  //scan_geo 20 18 0       ->  query 256 blocks of geodata
  //scan_geo_check 20 18   ->  check if geodata is loaded
  //geo_export 20 18       ->  export one region to .l2d
  //geo_export_all         ->  export all loaded regions

License: GPLv3 | Built on L2J Mobius C6 Interlude
by elbercasa (elitepvpers: mibanux)

If you find this useful, drop a star on GitHub and share it around.
PRs welcome — let's build something the L2J community has never had before.