How to script a KCD2 multiplayer server

Write your gamemode as a KCDS resource in TypeScript or JavaScript, with server and client scripts.

1. A resource's files

A resource is a folder in the server's resources\ folder:

hello/
  package.json
  tsconfig.json
  types/            shared.d.ts and server-api.d.ts from the KCDS-Types zip
  src/server/index.ts

The KCDS-Types zip comes with every release on the download page; its shared.d.ts and server-api.d.ts declare the server API for TypeScript (see TypeScript).

2. The manifest

package.json names the scripts in its own kcds section:

{
  "name": "hello",
  "version": "1.0.0",
  "scripts": { "build": "tsc -p tsconfig.json" },
  "devDependencies": {
    "typescript": "5.9.3"
  },
  "kcds": { "serverScripts": ["dist/server/index.js"] }
}

• serverScripts: compiled server CommonJS files.
• clientScripts: client CommonJS files the server sends to the players.
• sharedScripts: files run on both sides, before that side's scripts.
• resourceDependencies: resources this one needs.

tsconfig.json compiles the server scripts against the KCDS declarations:

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "commonjs",
    "lib": ["ES2022"],
    "types": [],
    "strict": true,
    "rootDir": "src/server",
    "outDir": "dist/server"
  },
  "files": ["types/shared.d.ts", "types/server-api.d.ts"],
  "include": ["src/server/**/*.ts"]
}

3. A command

Put this in src/server/index.ts. The API is the global kcds object and needs no import:

const { Events, Chat } = kcds.core;

Events.on("playerCommand", (player, command, args) => {
  if (command.toLowerCase() !== "hello") return;
  Chat.sendToPlayer(player, args.length ? args.join(" ") : "Hello!", {
    author: "Server"
  });
});

The host passes the command without its slash and splits the arguments at spaces.

4. Build and run

Compile the resource, put it in the server's resources\ folder and start the server. Type /hello in the chat.

5. Next steps

The docs cover every part of the SDK: areas, markers, the world, props, doors, carts, stashes, custom buffs and more, and the API reference lists every type and member, generated from the SDK definition on every build.