Open-Source Instant Messaging System (CIM) Overview and Features

The e‑commerce sector often requires real‑time communication such as notifications and customer service chat, and this article presents an open‑source instant messaging system called CIM that can serve those needs.

CIM is built on either the Mina or Netty framework and provides a push system supporting WebSocket, Android, iOS, desktop, and other applications, making it suitable for mobile apps, IoT, smart homes, embedded devices, and backend services.

The architecture follows a simple server‑plus‑client model that enables user‑to‑user chat, with optional cluster expansion for scalability.

The project is divided into server and client parts; the server integrates Netty with WebSocket, while various client SDKs (Android, iOS, web, desktop) consume the server APIs. All SDKs are packaged as Maven‑built JARs for IntelliJ IDEA projects.

The repository includes example applications (cim‑use‑examples), client SDK source code (cim‑client‑sdk), server SDK source code with Mina and Netty versions (cim‑server‑sdk), and a Spring Boot server implementation (cim‑boot‑server).

Feature previews show a web console at http://127.0.0.1:8080 , an Android client UI, and a web client UI, each demonstrated with screenshots.

In conclusion, the CIM system can be adapted for push notifications or chat services, with a backend that can be directly reused, and the article encourages readers to explore the code examples and consider adding the project to their collections.