Message Overview

Message Class
In the Tencent Cloud Chat SDK, the message class is V2TimMessage (Details), which will be frequently used for message sending and receiving.
The V2TimMessage class defines the following content:
Attribute
Description
Remarks
msgID
Message ID
It is empty when a message is created and is returned synchronously when sendMessage is called.
timestamp
Message timestamp
The time a message is sent to the server, which can be used for message sorting
sender
userID of the message sender
It can be set by users and must be the same as the userID passed in during login.
nickName
Nickname of the message sender
It can be set by users and modified by calling setSelfInfo. For more information, see User Profile.
friendRemark
Remarks of the message sender's friend
It is used by the receiver. For example, if Alice sets Bob's remarks to bob01, when Bob sends a message to Alice, Alice will see that friendRemark in the message is bob01. It can be set by calling setFriendInfo.
nameCard
Group name card of the sender
It applies only to group messages. For example, if Alice changes her group name card to doctorA and sends a message to the group, other group members will receive the message where the nameCard field is doctorA. The receiver can prioritize this field as the username for display. This field can be set by calling setGroupMemberInfo.
faceURL
Profile photo of the message sender
It can be set by users and can be used to download the photo.
groupID
Group ID
groupID is the group ID in a group message or nil in a one-to-one message.
userID
User ID
userID is the ID of the receiver in a one-to-one message or nil in a group message.
seq
Message serial number
The seq values of one-to-one messages are locally generated and may not be in ascending order and unique; the seq values of group messages are generated by the server and are in ascending order and unique in the group.
random
Random message code
It is generated in the SDK.
status
Message sending status
Currently, the following statuses are supported: sending, sent successfully, failed to send, deleted, imported locally, and recalled.
isSelf
Whether the message is sent by oneself
It can be used to filter messages.
needReadReceipt
Whether the message requires a read receipt
It is set by the sender and valid for the Ultimate edition on v6.1 or later. For more information, see Read Receipt.
priority
Message priority
It applies only to group messages and can be set by calling the sendMessage API.
groupAtUserList
List of users tagged in the group message
It applies only to group messages and stores the userID. For more information, see createAtSignedGroupMessage method.
elemType
Message type
Currently, the following message types are supported: text, custom, image, audio, video, file, geographical location, emoji, group tip, and merged messages. For more information, see Message Type.
textElem
Text message storage element
It needs to be created and entered when a text message is sent. When the message is received and elemType is identified as TEXT, the content can be parsed from textElem. For more information, see sendMessage method / onRecvNewMessage property.
customElem
Custom message storage element
It needs to be created and entered when a custom message is sent. When the message is received and elemType is identified as CUSTOM, the content can be parsed from customElem.
imageElem
Image message storage element
It needs to be created and entered when an image message is sent. When the message is received and elemType is identified as IMAGE, the content can be parsed from imageElem.
soundElem
Audio message storage element
It needs to be created and entered when an audio message is sent. When the message is received and elemType is identified as SOUND, the content can be parsed from soundElem.
videoElem
Video message storage element
It needs to be created and entered when a video message is sent. When the message is received and elemType is identified as VIDEO, the content can be parsed from videoElem.
fileElem
File message storage element
It needs to be created and entered when a file message is sent. When the message is received and elemType is identified as FILE, the content can be parsed from fileElem.
locationElem
Geographical location message storage element
It needs to be created and entered when a geographical location message is sent. When the message is received and elemType is identified as LOCATION, the content can be parsed from locationElem.
faceElem
Emoji message storage element
It needs to be created and entered when an emoji message is created. When the message is received and elemType is identified as FACE, the content can be parsed from faceElem.
mergerElem
Merged message storage element
It needs to be created and entered when a merged message is sent. When the message is received and elemType is identified as MERGER, the content can be parsed from mergerElem. For more information, see createForwardMessage method.
groupTipsElem
Group tip message storage element
Currently, a group tip message can be sent only by the server. When the message is received by the SDK and elemType is identified as GROUP_TIPS, the content can be parsed from groupTipsElem. For more information, see onRecvNewMessage property.
cloudCustomData
Custom message data
It is set by the sender and can be customized. It is saved in the cloud, will be sent to the receiver, and can still be pulled after the application is uninstalled and reinstalled.
isExcludedFromUnreadCount
Whether the message is excluded from the unread message count of the conversation
It is set by the sender. By default, messages are included in the unread message count. This field is supported by v5.3.425 or later.
isExcludedFromLastMessage
Whether the message is excluded from the lastMsg of the conversation
It is set by the sender. By default, messages are included in the lastMsg of the conversation. This field is supported by v5.4.666 or later.
offlinePushInfo
Custom offline push message
For more information, see Offline Push.
isRead
Whether the message is read at the local end
A message is read by default if it is sent by oneself.
isPeerRead
Whether the message is read by the receiver
It applies only to one-to-one messages.
localCustomData
Custom message data
It is set by the sender. It is saved locally, will not be sent to the receiver, and will become invalid after the application is uninstalled and reinstalled.
localCustomInt
Custom message data
It is set by the sender. It is saved locally, will not be sent to the receiver, and will become invalid after the application is uninstalled and reinstalled. It can be used to mark whether an audio or video message has been played back.
Message Type
Chat messages can be classified by message destination into two types: one-to-one messages (also called C2C messages) and group messages.
Message Type
API Keyword
Description
One-to-one message
C2CMessage
It is also called the C2C message. When sending a one-to-one message, you must specify the UserID of the receiver, and only the receiver can receive this message.
Group message
GroupMessage
When sending a group message, you must specify the groupID of the target group, and all users in the group can receive this message.
Chat messages can also be classified by content into text messages, custom (signaling) messages, image messages, video messages, audio messages, file messages, location messages, and merged messages.
Message Type
API Keyword
Description
Text message
TextElem
Ordinary text message
Custom message
CustomElem
It is a section of binary buffer and often used to transfer custom signaling in your application.
Image message
ImageElem
When the SDK sends an original image, it automatically generates two images in different sizes. The three images are called the original image, large image, and thumbnail.
Video message
VideoElem
A video message contains a video file and a thumbnail.
Audio message
SoundElem
It supports displaying a red dot before the playback of the audio message.
File message
FileElem
A file message cannot exceed 100 MB.
Location message
LocationElem
A location message contains three fields: location description, longitude, and latitude.
Merged message
MergerElem
Up to 300 messages can be merged.
Message Storage Policy
Chat messages can be classified by message storage policy into two types: online messages and non-online messages.
Online messages can be received only by online users and will not be pushed when they are offline. Non-online messages can be received by users whether they are online or not.
Online messages are delivered in real time and not stored on the server or in the SDK. Therefore, they cannot be pulled from historical messages after the device is changed or the application is uninstalled and reinstalled.
Note: 
1. All messages in an audio-video group are online messages.
2. Messages pushed to all users are online messages.
Non-online messages are stored in the SDK and on the server. By default, they are stored on the roaming server for seven days. If you want a longer storage period, you need to purchase the value-added service. For more information on the service content and billing, see Pricing.
These messages can be pulled from historical messages after the device is changed or the application is uninstalled and reinstalled.

Attribute	Description	Remarks
msgID	Message ID	It is empty when a message is created and is returned synchronously when `sendMessage` is called.
timestamp	Message timestamp	The time a message is sent to the server, which can be used for message sorting
sender	`userID` of the message sender	It can be set by users and must be the same as the `userID` passed in during login.
nickName	Nickname of the message sender	It can be set by users and modified by calling `setSelfInfo`. For more information, see User Profile.
friendRemark	Remarks of the message sender's friend	It is used by the receiver. For example, if Alice sets Bob's remarks to `bob01`, when Bob sends a message to Alice, Alice will see that `friendRemark` in the message is `bob01`. It can be set by calling `setFriendInfo`.
nameCard	Group name card of the sender	It applies only to group messages. For example, if Alice changes her group name card to `doctorA` and sends a message to the group, other group members will receive the message where the `nameCard` field is `doctorA`. The receiver can prioritize this field as the username for display. This field can be set by calling `setGroupMemberInfo`.
faceURL	Profile photo of the message sender	It can be set by users and can be used to download the photo.
groupID	Group ID	`groupID` is the group ID in a group message or `nil` in a one-to-one message.
userID	User ID	`userID` is the ID of the receiver in a one-to-one message or `nil` in a group message.
seq	Message serial number	The `seq` values of one-to-one messages are locally generated and may not be in ascending order and unique; the `seq` values of group messages are generated by the server and are in ascending order and unique in the group.
random	Random message code	It is generated in the SDK.
status	Message sending status	Currently, the following statuses are supported: sending, sent successfully, failed to send, deleted, imported locally, and recalled.
isSelf	Whether the message is sent by oneself	It can be used to filter messages.
needReadReceipt	Whether the message requires a read receipt	It is set by the sender and valid for the Ultimate edition on v6.1 or later. For more information, see Read Receipt.
priority	Message priority	It applies only to group messages and can be set by calling the `sendMessage` API.
groupAtUserList	List of users tagged in the group message	It applies only to group messages and stores the `userID`. For more information, see createAtSignedGroupMessage method.
elemType	Message type	Currently, the following message types are supported: text, custom, image, audio, video, file, geographical location, emoji, group tip, and merged messages. For more information, see Message Type.
textElem	Text message storage element	It needs to be created and entered when a text message is sent. When the message is received and `elemType` is identified as `TEXT`, the content can be parsed from `textElem`. For more information, see sendMessage method / onRecvNewMessage property.
customElem	Custom message storage element	It needs to be created and entered when a custom message is sent. When the message is received and `elemType` is identified as `CUSTOM`, the content can be parsed from `customElem`.
imageElem	Image message storage element	It needs to be created and entered when an image message is sent. When the message is received and `elemType` is identified as `IMAGE`, the content can be parsed from `imageElem`.
soundElem	Audio message storage element	It needs to be created and entered when an audio message is sent. When the message is received and `elemType` is identified as `SOUND`, the content can be parsed from `soundElem`.
videoElem	Video message storage element	It needs to be created and entered when a video message is sent. When the message is received and `elemType` is identified as `VIDEO`, the content can be parsed from `videoElem`.
fileElem	File message storage element	It needs to be created and entered when a file message is sent. When the message is received and `elemType` is identified as `FILE`, the content can be parsed from `fileElem`.
locationElem	Geographical location message storage element	It needs to be created and entered when a geographical location message is sent. When the message is received and `elemType` is identified as `LOCATION`, the content can be parsed from `locationElem`.
faceElem	Emoji message storage element	It needs to be created and entered when an emoji message is created. When the message is received and `elemType` is identified as `FACE`, the content can be parsed from `faceElem`.
mergerElem	Merged message storage element	It needs to be created and entered when a merged message is sent. When the message is received and `elemType` is identified as `MERGER`, the content can be parsed from `mergerElem`. For more information, see createForwardMessage method.
groupTipsElem	Group tip message storage element	Currently, a group tip message can be sent only by the server. When the message is received by the SDK and `elemType` is identified as `GROUP_TIPS`, the content can be parsed from `groupTipsElem`. For more information, see onRecvNewMessage property.
cloudCustomData	Custom message data	It is set by the sender and can be customized. It is saved in the cloud, will be sent to the receiver, and can still be pulled after the application is uninstalled and reinstalled.
isExcludedFromUnreadCount	Whether the message is excluded from the unread message count of the conversation	It is set by the sender. By default, messages are included in the unread message count. This field is supported by v5.3.425 or later.
isExcludedFromLastMessage	Whether the message is excluded from the `lastMsg` of the conversation	It is set by the sender. By default, messages are included in the `lastMsg` of the conversation. This field is supported by v5.4.666 or later.
offlinePushInfo	Custom offline push message	For more information, see Offline Push.
isRead	Whether the message is read at the local end	A message is read by default if it is sent by oneself.
isPeerRead	Whether the message is read by the receiver	It applies only to one-to-one messages.
localCustomData	Custom message data	It is set by the sender. It is saved locally, will not be sent to the receiver, and will become invalid after the application is uninstalled and reinstalled.
localCustomInt	Custom message data	It is set by the sender. It is saved locally, will not be sent to the receiver, and will become invalid after the application is uninstalled and reinstalled. It can be used to mark whether an audio or video message has been played back.

Message Type	API Keyword	Description
One-to-one message	C2CMessage	It is also called the C2C message. When sending a one-to-one message, you must specify the `UserID` of the receiver, and only the receiver can receive this message.
Group message	GroupMessage	When sending a group message, you must specify the `groupID` of the target group, and all users in the group can receive this message.