Development Guide
Welcome to RC Instant Messaging. This page provides a brief introduction to the architecture, service capabilities, and SDK products of RC Instant Messaging.
Architecture and Services
RC's instant messaging service does not require the establishment of a parallel user system outside the app, nor does it require synchronizing user information from the app to RC. It does not affect the existing system architecture and account system of the app, and can seamlessly integrate with the current business system.
Key features of RC's architecture design:
- No need to alter the existing app architecture; it can be directly embedded into the current code framework.
- No need to modify the existing app server architecture; simply deploy an independent service for user authorization.
- Focused on providing communication capabilities, using a private binary communication protocol that ensures lightweight, orderly, and reliable message delivery.
- Secure identity authentication and authorization methods, eliminating concerns about SDK capability abuse (e.g., spam messages or unauthorized mass messaging).
RC Instant Messaging supports various business scenarios, including one-to-one chat, group chat, ultra group, chatroom, and offers a rich set of client and server interfaces, with most features ready to use out of the box.
Business Type Overview
One-to-one chat (Private) refers to individual conversations. Regular group chat (Group) is similar to WeChat groups. Ultra groups and chatrooms have no upper limit on the number of users. Ultra groups (UltraGroup)1 are similar to Discord, offering a new group chat model with public/private channels and user groups, ideal for building super communities. Chatrooms (Chatroom) only allow online users to receive messages, making them suitable for live streaming, communities, gaming, social networking, and interest discussions. RC's Global IM UIKit provides ready-to-use UI components for one-to-one chat and regular group chat on Android, iOS, and Web platforms. For other scenarios, you can use the IMLib SDK to build your business experience.
The main differences between one-to-one chat, group chat, ultra groups, and chatrooms are as follows:
| Feature | One-to-One Chat (Private) | Group Chat (Group) | Ultra Group (UltraGroup)1 | Chatroom (Chatroom) |
|---|---|---|---|---|
| Scenario Analogy | Similar to WeChat private chat | Similar to WeChat groups | Similar to Discord | Chatroom |
| Features/Advantages | Supports offline push notifications and historical message roaming | Supports offline push notifications and historical message roaming, suitable for interest groups, office groups, and customer service communication | No member limit; supports message editing; offers public/private channels and user group features | No member limit; only online users can receive messages, and local history is cleared upon exit |
| Service Activation | Not required | Not required | Required | Not required |
| UI Components | Global IM UIKit2 | Global IM UIKit2 | Not provided | Not provided |
| Creation Method | Not applicable | Server API | Server API | Server API; automatically created when clients join |
| Termination/Dissolution Method | Not applicable | Server API | Server API | Server API; includes an auto-destruction mechanism3 |
| Member Limit | Not applicable | Up to 3000 members | No limit | No limit |
| User Join Limit | Not applicable | No limit | Up to 100 groups per user, with 50 channels per group | Default limit of 1 chatroom per user, but this can be disabled4 |
| Access to Pre-Join Messages | Not applicable | Not allowed by default, but can be disabled | Not allowed by default, but can be disabled | Clients can access up to 50 latest messages upon joining |
| Client Message Sending Rate | 5 messages per second per client5 | 5 messages per second per client5 | 5 messages per second per client5 | 5 messages per second per client5 |
| Server Message Sending Rate | 6000 messages per minute6 | 20 messages per second6 | 100 messages per second6 | 100 messages per second6 |
| Extensible Messages | Supported | Supported | Supported | Not supported |
| Message Editing | Not supported | Not supported | Supported | Not supported |
| Message Reliability | 100% reliable | 100% reliable | 100% reliable | Messages exceeding server consumption limits are actively discarded7 |
| Local Message Storage | Supported on mobile and PC | Supported on mobile and PC | Supported on mobile and PC | Not supported |
| Cloud Message Storage | Requires activation, storage for 6 - 36 months8 | Requires activation, storage for 6 - 36 months8 | Default storage for 7 days, with options for 3 - 36 months8 | Requires activation, storage for 2 - 36 months8 |
| Offline Message Caching | Default 7-day offline message caching | Default 7-day offline message caching | Not supported | Not supported |
| Local Message Search | Supported | Supported | Supported | Not supported |
| Offline Push Notifications | Supported | Supported | Supported, with adjustable push frequency | Not supported |
Footnotes:
- Ultra group service is only available for Chat Ultimate Plan.
- Global IM UIKit is supported on Android, iOS, and Web.
- Chatrooms have an auto-destruction mechanism. By default, if no one speaks in the chatroom for a specified period (default 1 hour) and no one joins, all members will be kicked out, and the chatroom will be destroyed. You can adjust the chatroom's survival conditions and duration.
- Users can join multiple chatrooms. Refer to the knowledge base document: Enable Single User to Join Multiple Chatrooms.
- Clients are limited to 5 messages per second across all business types, but this can be increased for a fee.
- This is the default server API rate, which can be increased for a fee. For detailed rate limits, refer to the API Interface List.
- When chatroom message volume is high, messages exceeding server consumption limits are actively discarded. You can change the message discard policy through user allowlists, message allowlists, and custom message level services. If a user is on the chatroom's allowlist, their messages will not be discarded even when message volume is high. For more information on server consumption limits and how to change the message discard policy, refer to the server documentation Message Priority Service, Chatroom Allowlist Service.
- Refer to the knowledge base document: How Long Are One-to-One Chat, Group Chat, Chatroom, and Ultra Group Messages Stored on RC?.
Advanced and Extended Features
The IM service supports advanced and extended features, including but not limited to the following:
- User Management: For example, user bans, blocklists, allowlists, group and chatroom muting, and chatroom member bans.
- Online Status Subscription: Synchronizes the online, offline, or logout status of each user terminal to the server address specified by the app developer.
- Multi-Device Message Synchronization: Supports simultaneous message synchronization across desktop, mobile, and multiple web clients.
- Post-messaging Callback: Supports synchronizing message data from one-to-one chat, group chat, chatroom, and ultra group to the server address specified by the app developer.
- Content Moderation: Supports setting up sensitive word lists to filter or replace sensitive words in messages. Using the message callback service, messages can be forwarded to the server address specified by the app developer, where the app server determines whether the message can be sent to the target recipient.
- Push Notification Service: RC integrates with major push platforms, covering Xiaomi, Huawei, Honor, OPPO (for OnePlus and realme), vivo, Meizu, FCM, and APNs system-level push channels. It supports tag-based push, various push scenarios, push statistics, and broadcast to users.
Client SDK
RC's Instant Messaging (IM) Client SDK offers a rich set of components and interfaces, with most features ready to use out of the box. When combined with the IM Server API, it can meet a wide range of business requirements.
Before integrating the RC SDK, we recommend using the quick start guide and sample projects for evaluation.
How to Choose the SDK
IMLib and Global IM UIKit are two classic client SDKs provided by RC's IM service. The client functionalities are consistent across different platforms.
-
IMLib is an instant messaging capability library that encapsulates communication capabilities and objects such as conversations and messages. It does not include any UI components.
IMLib already supports most mainstream platforms and frameworks, including Android, iOS, Web, Flutter, React Native, Unity, and WeChat Mini Programs.
-
Global IM UIKit is an instant messaging UI library that integrates conversation interfaces and provides extensive customization features.
Global IM UIKit supports Android, iOS, and Web.
You can choose based on your business needs:
- Develop your application based on IMLib to embed RC's instant messaging capabilities into your app and develop your own UI interface.
- Develop your application based on Global IM UIKit to directly integrate the UI components provided by Global IM UIKit into your product, customize interface component functionalities, and save development time. You can also use independent feature plugins provided by RC to extend Global IM UIKit's capabilities.
Platform Compatibility
The IM client SDK supports mainstream mobile operating platforms, with consistent client functionality across multiple devices and support for multi-platform interoperability. The following data is based on the 5.X version SDK.
| Platform/Framework | Interface Language | Supported Architectures | Notes |
|---|---|---|---|
| Android | Java | armeabi-v7a, arm64-v8a, x86, x86-64 | System version 5.0 and above |
| iOS | Objective-C | Real devices: arm64, armv7. Simulator: arm64 (5.4.7+), x86_64 | System version 9.0 and above |
| Web | Javascript | --- | --- |
| Electron | Javascript | See below Electron Version and Architecture Support | Electron 11.1.x, 14.0.0, 16.0.x, 20.0.x |
| Flutter | Dart | --- | Flutter 2.0.0 and above |
| React Native | Typescript | - | react-native 0.60 and above |
| uni-app | Javascript | --- | uni-app 2.8.1 and above |
| Unity | C# | armeabi-v7a, arm64-v8a | --- |
-
Electron Version and Architecture Support:
The Electron framework requires support through the Electron module of the Web SDK (see Electron Integration Solution). It is suitable for developing desktop IM applications that run on Windows, Linux, and MacOS platforms. The table below lists the currently supported Electron versions, desktop operating system versions, and CPU architectures:
Electron Version Platform Supported Architectures Notes Electron 11.1.x Windows ia32 (x86) win32-ia32Electron 11.1.x Linux x64 linux-x64Electron 11.1.x Linux arm64 linux-arm64Electron 11.1.x Mac x64 darwin-x64Electron 14.0.0 Windows ia32 (x86) win32-ia32Electron 14.0.0 Mac x64 darwin-x64Electron 16.0.x Windows ia32 (x86) win32-ia32Electron 16.0.x Mac x64 darwin-x64Electron 20.0.x Windows ia32 (x86) win32-ia32Electron 20.0.x Mac x64 darwin-x64Electron 20.0.x Mac arm64 darwin-arm64
Version Support
The latest versions of the IM client SDK for each platform/framework are as follows (--- indicates not yet supported):
| SDK/Platform | Android | iOS | Web | Electron | Flutter | React Native | Unity | uni-app | Mini Program |
|---|---|---|---|---|---|---|---|---|---|
| IMLib | 5.10.x | 5.10.x | 5.9.x | 5.9.x | 5.6.x | 5.2.x | 5.1.x | 5.4.x | 5.9.x |
| Global IM UIKit | 1.0.x | 1.0.x | 1.0.x | 1.0.x | --- | --- | --- | --- | --- |
App Size Increase After SDK Integration
- App Size Increase After Integrating IM SDK (Android)
- App Size Increase After Integrating IM SDK (iOS)
IM Service Server
The IM Service Server provides a set of API interfaces and open-source SDKs in multiple languages.
Server API
You can use the Server API to integrate RC services into your IM service system, building the backend service system for your IM app. For example, you can obtain user identity tokens (Token) from RC, send/recall messages from your app's product server to users, or manage the list of muted users.
Visit the RC IM Service Server API Documentation.
Server SDK
RC offers open-source Server SDKs in multiple languages:
- server-sdk-java (GitHub) · (Gitee)
- server-sdk-php (GitHub) · (Gitee)
- server-sdk-go (GitHub) · (Gitee)
Console
Using the Console, you can manage developer accounts and applications, activate premium services, view application data reports, and billing information.
Some IM features are only available after activating the service. For more details, visit the Service Management page in the Console.
Instant Messaging Data
If you need to store historical messages for one-to-one chats, group chats, or chatroom sessions on the RC server, you can [activate the message cloud storage service]. The default long-term storage duration depends on the business type and can be adjusted as needed. The data stored by this service is only used for clients to retrieve historical messages.
If you need to retrieve the message history of all users, please [activate the Server API historical message log download].After activation, you can use the server API to retrieve message logs for up to three days.
Additionally, you can activate the post-messaging callback service to synchronize messages in real-time to your business server.
You can visit the [Data Statistics] page in the Console to view instant messaging user statistics, business statistics, message statistics, and business health check data. After activating the corresponding services, you can also access data such as business analysis.
RC does not utilize customer data. At the same time, RC provides a comprehensive data privacy protection policy. Refer to the SDK Privacy Policy.