Introduction

Kingdoms Connected (KCDC) puts other players into Kingdom Come: Deliverance II’s own world. Everything that makes a server yours lives in resources: folders of JavaScript or TypeScript the server loads.

	Server half	Client half
Runs on	The dedicated server	Every connected player’s game
Owns	Everything shared: players’ inventories and progression, horses, NPCs, props, quests, the clock	Nothing shared. It reads what this machine sees and draws UI
Typical jobs	Spawns, commands, game rules, economy, persistence	Menus, HUD, key binds, placement previews
Reference	Server API	Client API

Start here

Read Getting started in order:

1. Install and run a server: from nothing to standing in your own server, with a Steam, GOG or any other copy of the game.
2. Write your first resource: a command, a key bind and a server round trip.
3. Use TypeScript: autocomplete and type checking for the whole API.
4. Structure a larger resource: folders that stay easy to change.
5. Logs and debugging: find out why nothing happened.

Find it fast

Section	I want to…	Page
Players	Greet players, choose where they spawn and respawn	Join, spawn and respawn
Players	Read health, stamina, stats or skills	Read and set stats
Players	Set health, energy or nourishment and restore living characters	Set and restore stats
Players	Grant XP, levels and perks, slow down levelling, keep a character	Skills, XP and perks
Players	Teleport, kick, revive or rename a player	Teleport, kick and other actions
Players	Give, take or drop items, read equipment	Items
Players	Carry sacks, baskets or a downed player in the arms	Carrying
Players	Register custom types and personalize their inventory rows	Custom items
Players	Approve food and potions or replace their effects	Food and potions
Players	Read, move or save a player’s inventory, set item quality	Inventories
Players	Let players brew potions, refuse or reward a batch, refund an unfinished craft	Alchemy
Players	Let players forge at smitheries, teach recipes, decide what a failed workpiece costs	Smithing
Players	Change a face, hair or body; add a buff	Appearance, Buffs
Players	Add /commands or send chat messages	Chat and /commands
Players	Seat two players at a dice table, list the tables, settle what they played for	Dice matches
World	Change the time or the weather	Time of day and weather
World	Place objects, fill chests, open virtual storage, or play particle effects	Props, Stashes, Effects
World	Lock a door, open a castle gate	Lock doors, open gates
World	Mark a spot, detect players entering an area	Markers and trigger zones
World	Trace a ray, tell what it hit (door, tree, rock), find the ground, list nearby entities	Raycasts and nearby entities
World	Spawn a cart or wagon and let players drive it	Carts and wagons
World	Build a trebuchet or cannon, fire it, let players work it	Siege engines
World	Create a map offline, save blueprints and export it to a server	World Builder
World	Draw gameplay areas and invisible collision boundaries	World Builder areas
World	Let an assistant or local application control the offline editor	MCP automation
World	Align objects and organize a project with favorites and layers	Grid, favorites and layers
World	Inspect a scene at dusk or in rain	Preview light and weather
World	Find exported objects, areas and routes in a server script	World exports in scripts
World	Refill or disable a shared stew pot	Shared stew pots
World	Remove or move the level’s own walls and gates from scripts	Level edits
World	Let players pick herbs, refuse a pick, or change how fast plants regrow	Herb gathering
NPCs and animals	Spawn NPCs and make them walk, follow or patrol	Spawn NPCs, Move NPCs
NPCs and animals	Route NPCs around walls, plan paths, find the floor or a random walkable spot	Navigation mesh
NPCs and animals	Draw, preview and run named NPC patrols	Named patrol routes
NPCs and animals	Order melee and bow combat	NPC combat
NPCs and animals	Spawn predators and prey, choose population and respawn rules	Animal populations
NPCs and animals	Set corpse loot and harvest animals	Corpse loot
NPCs and animals	React when an NPC is hit, dies or is talked to	NPC events
NPCs and animals	Spawn horses or dogs	Horses, Dogs
NPCs and animals	Give a player their own horse, keep it when they leave	Horse owners
Quests, dialogue and shops	Add a quest, show dialogue choices, open a shop	Quests, Dialogue, Shops
Quests, dialogue and shops	Track a quest for a player, mark objectives on the map	Quest tracking
Core concepts	React to any game event	Events and handlers
Core concepts	Send data to a player’s client and back	Send data between server and client
Core concepts	Store a team, a score or a role on a player	Entity state bags
Core concepts	Ship my own models, textures, animations, sounds or effects, or replace the game’s	Custom assets
Client scripting	Read the local player, bind a key	Local player, Key binds
Client scripting	Let a player follow another player or an NPC guide	Following
Client scripting	Replace an item’s native inventory action	Inventory use
Client scripting	Cut or glide to a scripted view	Camera shots
Client scripting	Move the camera, fly a free camera	Camera and noclip
Client scripting	Play sounds, use voice chat, set Discord status	Sound and voice, Discord presence
Client scripting	Make the screen look drunk, hurt or dreamlike	Screen effects
Client scripting	Draw debug lines, boxes and areas in the world	Debug gizmos
User interface	Show your own books and letters in the player’s hands	Books and letters
User interface	Show an HTML menu and talk to it	Web views, Page data bridge
User interface	Show a HUD message, nametag or map blip	HUD, Map and blips
User interface	Show a “Press [key] to …” hint, let a player design their look	Action hints, Character creator
User interface	Turn off the game’s own inventory, map or journal	Native UI screens
Tutorials	Give a personalized letter and open its pages	Readable custom letter
Getting started	Try items, crafting and companions on a development server	Development playground
Tutorials	Build a complete feature end to end	/command system, NPC shop, Capture-zone mode
Tutorials	Connect a World Builder route to a guard	Village patrol
Tutorials	Call editor tools directly from PowerShell over HTTP	World Builder HTTP
Tutorials	Recreate a route and inspect a guard with an assistant	MCP patrol tutorial
Tutorials	Defend a yard drawn in World Builder	Guarded yard
Tutorials	Lead a player on an authored NPC route	Walking tour
Hosting a server	Run a dedicated server, change its settings, load world exports	Run a server, Options and overrides, server.json
Hosting a server	Run the official Docker image or a Pterodactyl egg	Docker and panels
Hosting a server	Let players connect, list the server publicly with a logo	Let players connect, Server browser listing
Resources	Look up a face, horse breed, item, buff or effect name	Game resources and catalogs

How the sidebar is organised

Group	What is in it	Runs on
Getting started	Install, first resource, TypeScript, layout, debugging	Both
Core concepts	Authority, resources, events, networking, state, positions, virtual worlds, sharing, custom assets	Both
Players	Join and spawn, stats, progression, actions, items, carrying, inventories, alchemy, smithing, appearance, buffs, chat, dice	Server
World	Clock and weather, props, stashes, doors, markers, effects, raycasts, carts, siege engines, level edits, herb gathering, World Builder exports, stew pots	Server (raycasts: both)
NPCs and animals	NPCs, combat, named patrols, animal populations, horses and their owners, dogs, navigation	Server
Quests, dialogue and shops	Journal quests and tracking, dialogue choices, vendors	Server
Client scripting	Local player, key binds, camera, placement, sound, Discord, following, screen effects, debug gizmos	Client
User interface	Web views, page bridge, HUD, map, native screens and menus, action hints, character creator	Client
Tutorials	Multi-file builds of complete features	Both
Hosting a server	Running, command-line options and overrides, connecting, listing, the official Docker image	Server operators
Resources	Every name the catalogs carry: faces, beards, horse breeds and gear, souls, items, buffs, effects, markers, blips, props	Reference

A taste

Two files are a complete resource. The server half greets people and spawns a horse on /horse:

server/main.js

Events.on("playerSpawned", (player) => {
  Chat.sendToPlayer(player, `Welcome, ${player.nickname}. Type /horse for a ride.`);
});

Events.on("playerCommand", (player, command) => {
  if (command !== "horse" || !player.ready) return;
  Horse.spawn(player.position, undefined, undefined, `${player.nickname}'s horse`);
});

The client half shows the player their health when they press F8:

client/main.js

Key.bind("f8", "down", () => {
  const me = LocalPlayer;
  if (me) Hud.showInfoText(`${Math.round(me.health)} / ${Math.round(me.maxHealth)} health`);
});

Write your first resource builds one like it step by step.

One rule explains most of the API

Each player’s own game keeps their body’s state (health, clothing, position) and is the authority for it; the server is the authority for everything shared, and for each player’s inventory and progression. So player.teleport(...) sends that game a request, and most verbs return whether the request went out, not whether it worked. See Server vs client authority.

Where the reference comes from

The API reference is generated from the runtime’s own bindings, so when a guide and the reference disagree, the reference wins. Please open an issue so the guide gets fixed.