Plugin Documentation

ColyseusMP
Colyseus multiplayer client

A client for the Colyseus multiplayer server: join rooms, sync state and exchange messages.

v1.0.0
UE 4.27–5.0+
Win64 · Mac · Linux
Category Networking
Disabled by default
Alpha XP
ColyseusMP diagram
ColyseusMP — architecture & feature overview

Overview

ColyseusMP wraps the Colyseus C++ SDK (Client, Room, state schema) and now adds a small Blueprint helper layer for endpoints and room names.

Fork note Module ColyseusClient was renamed to ColyseusMP for UE 4.27–5.0+. The SDK is pure C++ (Client/Room), and a new ColyseusUtilityLibrary adds the plugin's first Blueprint surface.
Disabled by default This plugin ships the bundled third-party library nlohmann/json, msgpack and is shipped with "EnabledByDefault": false. Enable it from Edit → Plugins (or set the flag in its .uplugin) once the library builds on your target platform.

Requirements

RequirementDetails
Unreal Engine4.27–5.0+
Bundled librarynlohmann/json, msgpack (in Source/ThirdParty)
LanguageBlueprints and/or C++
PlatformsWin64 · Mac · Linux

Installation

  1. Copy the ColyseusMP folder into your project's Plugins/ directory.
  2. C++ projects: regenerate project files and build. Blueprint-only projects can launch the editor directly.
  3. Open Edit → Plugins and confirm ColyseusMP is enabled (it is off by default — turn it on).

Helpers (Colyseus Utility Library)

NodeTypeDescription
Build Colyseus EndpointPureBuild ws(s)://host:port for the Colyseus server.
Is Valid Room NamePureValidate a room name (non-empty, no whitespace).
Is Valid Colyseus EndpointPureValidate a ws(s) endpoint with a host.

C++ SDK

The Colyseus Client and Room classes are used directly from C++ for joining rooms and receiving state changes. See the SDK headers under Source/Colyseus/Public.

Utility node pack

General-purpose networking utilities added to UColyseusUtilityLibrary — available from Blueprints and C++.

NodeTypeDescription
CRC32 Of BytesPureCRC32 checksum of a byte array.
MD5 Of String / SHA1 Of StringPureHex digests of a UTF-8 string.
Make Guid StringPureNew random GUID (hyphenated).
Now Unix SecondsPureCurrent UTC time as Unix seconds.
Unix Seconds To ISO8601PureUnix seconds → ISO-8601 UTC string.
Format Byte SizePureHuman-readable size, e.g. 1536 → 1.5 KB.
Random TokenPureRandom alphanumeric token (ids, nonces).
XOR Bytes With KeyPureXOR bytes with a repeating key (obfuscation, not encryption).
Is Valid HostnamePureRFC-952/1123-style hostname validation.

Credits

© Alpha XP — alphaxp.net. Developed and maintained for UE 4.27–5.0+.