The OpenMon Hub
Tools > MCE > OpenMon Hub, or Ctrl+Shift+H.
The Hub is the front door to the engine's editor tooling: setup, data authoring, art, importing, the online layer, and world generation, each on its own tab. Nothing here is required to ship a game — every action has a menu-item equivalent — but it is where the work is fastest, and it is the one window worth docking permanently.
Every screenshot below is a real capture of the editor, not a mockup.
Welcome — setup status and the mode switch
The first thing to read is the Project Setup bar. Green means the layers, render pipeline, build settings and player settings are all configured and you can press Play.
Underneath it are the two buttons that decide how the whole project behaves:
The blue button is the mode you are currently in. In the capture above the project is Offline, so Setup Offline is blue and carries a check. Pressing the grey one switches, and switching is not just a flag — it flips the scripting define, registers the scenes that mode needs, points the configuration at the right target, and seeds the data the mode requires. One press, no manual steps.
Online mode ships in the Pro, Source and Studio editions. In Starter and Indie the button is disabled and its tooltip says so; the rest of the tab works normally.
The rest of the tab is quick access: open the documentation, the Command Palette (Ctrl+Shift+M), play straight from the init scene, or validate the database.
Database — where your game's content lives
Two halves. The top browses and checks what exists — Database Browser to search every monster, move, ability and item; Type Chart Editor for the effectiveness matrix; Validate Database to scan for missing references, invalid stats and integrity problems.
The bottom half creates. Each button makes one asset of one kind and opens it in
the Inspector, so you can go from empty project to a species, a type, a ball, a
region, an encounter table or a quest without hunting through
Create > MCE > ... menus.
Validate Database is the one to run before every build. It is the difference between finding a broken reference now and finding it in a player's crash.
Art Studio — sprites and monster art
Three tools for getting art into the engine: Monster Creator to design and preview a monster visually, Sprite Sheet Slicer to slice a sprite sheet into animation frames, and Import Follower Spritesheets to import follower sheets for the overworld.
Importer — bringing in an existing project
The top of the tab imports Pokémon Essentials v20 / v21 / v21.1 projects (the Hub labels the section "RPG Maker Essentials Importer"). Import Wizard is the guided path; Full Reimport re-runs the pipeline over a project you have already brought in; Project Combiner merges several imported projects into one database.
Under Post-Import Setup are two tools that are easy to miss and you will want: Starting Map Picker chooses which map the player spawns on after the main menu (the step between "the import finished" and "the game is playable"), and Display Mode per Map draws each imported map in 2D or 2.5D and tunes its 2.5D camera.
Further down the same tab are the sections for the cartridge importers -- HeartGold / SoulSilver, FireRed and Black / White -- each with the buttons that import the game, apply its game profile so it can be played, and restore the demo afterwards. They have their own guide: Imported Games and Game Profiles.
Full walkthrough of the Essentials path in Import from Pokémon Essentials.
The Essentials importer ships compiled in the Indie and Pro editions, and as source in Source and Studio. The cartridge importers ship only in Studio. The Starter has no importer.
Online — the multiplayer layer and its server
Top to bottom it follows the order you actually need things in.
Connection Mode states plainly which mode the project is in and offers the
switch. Online Setup (Nakama) is first-time configuration — the wizard, the
OnlineConfig asset, and generating plus registering the addon scenes.
Species Data is a shortcut to one part of a bigger job. Species are one of eleven families of data the server needs (type chart, natures, experience, species, moves, abilities, statuses, encounter tables, trainer rosters, shop catalog and collision), and the whole job lives in its own tab — see Seeding below. The status line here reports what was last exported and whether it still matches the active database — above, 667 species.
Docker Server drives the local development server: start, stop, restart, open the admin console, tail the logs.
Setup guide: Online Setup. Seeding in detail: Species Seeding.
The online layer ships in the Pro, Source and Studio editions.
Seeding — teaching your server your game
Online play is server-authoritative: the server decides damage, captures and rewards. It cannot be the authority over content it has never seen, so before anyone plays you have to hand it your game's data. That is what this tab does, in five steps.
1. Export seed files runs every exporter and writes JSON to SeedData/. It
touches no network. What it reports is the part that matters: for each family it
shows how many rows it emitted and how many it recognised but could not
emit, with the reason. A move whose rule the server does not implement is
listed here rather than quietly dropped — your server will refuse that move by
name, which is deliberate. A server missing a rule is recoverable; a server
confident in a wrong rule is not.
2. Where it will be written reads the host and port out of your
OnlineConfig and says, before anything is sent, whether that is this machine
or somewhere else. It also names where the HTTP key came from.
The key is the server's runtime http_key — not the ServerKey your game
clients use; they are different values and mixing them up answers 401. Type it
in the field and it is stored per machine, in ProjectSettings/. It is never
written inside Assets/, so it cannot travel inside a .unitypackage, and it is
git-ignored, so it cannot reach a repository. Leave the field empty to use the
NAKAMA_HTTP_KEY environment variable instead.
3. Push to the server sends the files. Against your own machine it just goes. Against any other host the button stays disabled until you tick a box that names the host — seeding overwrites what a live server holds, and against a server other people can reach that has to be a decision, not a side effect of a click. The box clears itself if the target changes. Large catalogs are split into chunks automatically; the move catalog does not fit in one request.
4. World rules lists the options that stop being the player's choice once a server runs the world: everyone plays by the same rules. See World Options.
5. Ask the server what it has calls the server's own status RPC with the same key the push used, and reports what it says is still missing.
World Gen — generating a region
Procedural region generation. Set a seed and world size, tune how many cities, gyms and Elite Four locations to place, adjust routes and content density, then Generate World and read the result in the preview pane. PNG and JSON export sit under the button.
Add to Game turns the region into game data. It creates an empty map scene per city and per route under
Assets/GeneratedWorld/World<seed>/ (grid, layers, landing point and SceneInfo), registers each one where the game
loads, saves and finds its maps (OpenMonSceneManager, Build Settings, SavegameManager and WorldDatabase), and adds a
region whose town map is the generated image, with one location per city and route; cities are fly destinations. Paint
each map with the Map Editor and connect the maps to each other yourself (the importers bring their own map connections).
Online, the maps reach the server through the Seeding tab, like any other map.
The seed makes it reproducible: same seed and same parameters give the same region, so a layout you like can be regenerated exactly rather than saved by hand.
About — versions and links
Engine version, Unity version and render pipeline, plus links to the website, these docs, the Discord, the licence and the changelog.
Worth knowing where it is for one reason: when you report a problem, the version line here is the first thing anyone will ask for.
The three tabs not shown here
The Hub has eleven tabs: Welcome, Database, Art Studio, Importer, Online, Seeding, Build, Map Editor, World Gen, GM and About. Three are deliberately absent from this page:
- Map Editor — it is a whole workflow rather than a panel of buttons, and it has its own guide: Map Editor.
- GM — the in-editor game-master console of the online layer, covered by GM Mode.
- Build — release tooling used to produce the distributable packages themselves. It does not appear in any edition you can buy, so documenting it here would only show you buttons you do not have.
Tools > MCE > OpenMon Hub (UI Toolkit) opens an opt-in edition of the Hub built with
UI Toolkit. It lists the same eleven tabs and shares the same actions with the default
Hub, but only the Welcome and Build tabs are migrated so far; the rest route back to
the default window. Tools > MCE > OpenMon Hub (Ctrl+Shift+H) remains the one to use.
Next
- First run, screen by screen — what the engine does once you press Play.
- Your first monster — authoring content with the Database tab.