Basic features

This document outlines the basic features of RC's one-to-one chat, group chat, ultra group, and chatroom services for developers.

One-to-One Chat

One-to-one chat refers to a conversation between two users. RC does not maintain user relationships, and messages can be sent without verifying if the users are friends. Conversations are established and maintained by RC. When the app is running in the background or the app process is terminated, push notifications will be received for new messages.

Feature	Description
Offline Messages	Supports offline message storage with a configurable storage duration (1 to 7 days). The default storage period is 7 days.
Message Notifications	Push notifications are supported for new messages in one-to-one chats when the user is offline.
Local Storage	Received messages are stored locally on the mobile device, enabling local message search.
Historical Messages	Cloud storage for messages is available. You need to enable Cloud Storage for One-to-One and Group Messages. The default storage duration is 6 months.
Message Deletion	Messages stored locally and in the cloud can be deleted. You can delete specific messages or all historical messages in a conversation.
Message Search	Supports searching for messages in a specific conversation by keyword or user.
Read Receipts	After sending a one-to-one message, you can use this feature to send a read receipt request to check the message's read status.
Message Recall	After a message is sent, it can be recalled. IMLib has no time limit for recalling messages; Global IM UIKit defaults to a 2-minute recall window, which is configurable.
Do Not Disturb for One-to-One Chat	You can set whether to receive notifications for new messages in a specific one-to-one chat. By default, notifications are enabled.
Blocklist for One-to-One Chat	If you do not want to receive messages from a specific user, you can add them to the blocklist. Each user can set their own blocklist. Use the Server API to set the blocklist.
Allowlist for One-to-One Chat	For customers with restrictions on message sending between users, the user allowlist feature can be used. Only users added to the allowlist can receive one-to-one messages. Use the Server API to set the allowlist. The user allowlist service cannot be used simultaneously with the user blocklist service. RC enables the user blocklist service by default. You can enable the One-to-One User Allowlist service in the Basic Features section of the RC Console. The service takes effect 15 minutes after activation, and the blocklist service will no longer be effective.
Status Messages	Online users will receive this message, but offline users will not. Status messages are not counted or stored.

Group Chat

Group chat refers to conversations among more than two users. Group member information is provided and maintained by the app, and RC is responsible for delivering messages to group members.

Feature	Description
Offline Messages	Supports offline message storage with a configurable storage duration (1 to 7 days). The default storage period is 7 days.
Message Notifications	Push notifications are supported for new messages in group chats when the user is offline.
Local Storage	Received messages are stored locally on the mobile device, enabling local message search.
Historical Messages	Cloud storage for messages is available. You need to enable Cloud Storage for One-to-One and Group Messages. The default storage duration is 6 months.
Message Deletion	Messages stored locally and in the cloud can be deleted. You can delete specific messages or all historical messages in a conversation.
Message Search	Supports searching for messages in a specific conversation by keyword or user.
Read Receipts for Group Messages	After sending a group message, you can use this feature to send a read receipt request to check the message's read status.
Message Recall	After a message is sent, it can be recalled. IMLib has no time limit for recalling messages; Global IM defaults to a 2-minute recall window, which is configurable.
Do Not Disturb for Group Chat	You can set whether to receive notifications for new messages in a specific group chat. By default, notifications are enabled.
Create Group	There is no limit to the number of groups in an app. The default maximum number of members per group is 3000.
Join Group	Each group can have a maximum of 3000 members. A user can join multiple groups without restriction. By default, after joining a group, only messages sent after joining can be viewed. To view messages sent before joining, you need to enable Cloud Storage for One-to-One and Group Messages and then enable New Users Access Historical Messages Before Joining.
Leave Group	Removes a user from a group, and they will no longer receive messages from that group.
Dismiss Group	Dissolves a specific group, and all members will no longer receive messages from that group.
Query Group Members	Retrieves the user IDs of members in a specific group.
Refresh Group Information	Supports updating the group name.
Synchronize User Groups	If the app server already has group data before integrating RC, this service can be used for synchronization.
Mute Group Members	Muted users can receive and view messages from other group members but cannot send messages via the client SDK.
Mute All Group Members	All members of a specific group cannot send messages. If certain users need to speak, they can be added to the group's mute allowlist.
Mute Allowlist for Group	When a group is muted, users in the mute allowlist can send group messages.
Send Group Messages	Sends messages to all members of a group.
Send Targeted Group Messages	Sends messages to one or more specified users in a group. Other group members will not receive the message.
Send @Messages in Group	Sends messages that require special attention from specified group members.
Status Messages	Online users will receive this message, but offline users will not. Status messages are not counted or stored.

Chatroom

Chatroom members have no user limit, and massive concurrent messages are delivered instantly. Users who exit the chat interface are considered to have left the chatroom and will no longer receive any messages from the chatroom. There is no push notification feature. The session relationship is established and maintained by RC. Through the SDK's related interfaces, users can join or leave chatrooms.

Feature	Description
Offline Messages	Offline messages are not supported. Only users currently online can receive messages in the chatroom.
Member Limit	Chatrooms have no member limit.
Message Notifications	Chatroom messages do not have message notifications.
Local Storage	Local chatroom messages are deleted after leaving the chatroom. Message search is not supported.
Historical Messages	Cloud storage for messages is available. You need to enable chatroom message cloud storage. The default storage duration is 2 months.
Create Chatroom	There is no limit to the number of chatrooms in an app.
Destroy Chatroom	Dissolves a specific chatroom, and all members will no longer receive messages from that chatroom.
Query Chatroom Information	Queries basic chatroom information, including: chatroom ID, name, and creation time.
Get Chatroom Members	Retrieves chatroom member information, including: user ID and join time. A maximum of 500 member records are returned, sorted by join time.
Mute in Specific Chatroom	Mutes a user in a specific chatroom. Muted users can receive and view chatroom messages but cannot send messages.
Global Mute in All Chatrooms	Mutes a user in all chatrooms in the app. Muted users can receive and view chatroom messages but cannot send messages.
Ban User in Chatroom	Banned users are kicked out of the specified chatroom and cannot rejoin for a set period of time.
Mute All in Specific Chatroom	Mutes all users in a specific chatroom. All users in the chatroom cannot send messages.
Low-Priority Messages	Certain message types can be set as low-priority. When server load is high, low-priority messages are discarded first to ensure that high-priority messages are not discarded.
Message Allowlist	Message types in the allowlist are protected and will not be discarded even when chatroom message volume is high.
Auto-Exit for Chatroom Users	After a chatroom user goes offline, a 30-second countdown starts from the first new message. The user will automatically exit the chatroom after 30 seconds or after 30 new messages are generated in the chatroom.
User Allowlist for Chatroom	Messages sent by users in the allowlist are protected and will not be discarded even when chatroom message volume is high. Additionally, users in the allowlist are protected from auto-exit.
Chatroom Keepalive	The chatroom keepalive feature ensures that the chatroom is not automatically destroyed and can only be destroyed by calling the API.
Chatroom Status Synchronization	When a chatroom's status changes, it will be synchronized in real-time to the developer's app server. Currently supported synchronization statuses include: creation, destruction, member join, and member exit.
Custom Chatroom Attributes	Each chatroom can have up to 100 custom attributes stored as key-value pairs. Custom attributes are destroyed when the chatroom is destroyed.
Message Recall	After a message is sent, it can be recalled. IMLib has no time limit for recalling messages; Global IM UIKit defaults to a 2-minute recall window, which is configurable.