User content message format

User content messages represent messages that users exchange during chat, including text, image, GIF, voice, file, short video, location, quote, and combined forward messages.

Text message

ObjectName: RC:TxtMsg

Built into the client SDK. When sending via the server API, set the message type field to RC:TxtMsg and pass the content structure as a serialized JSON string in the content field.

Content structure

JSON
{
  "content":"@Alice Hello world!",
  "mentionedInfo":{
    "type":2,
    "userIdList":["zhangsan"],
    "mentionedContent":"Someone mentioned you"
  },
  "user":
  {
    "id":"4242",
    "name":"Robin",
    "portrait":"http://example.com/p1.png",
    "extra":"extra"
  },
  "extra":""
}

Field	Type	Required	Description
`content`	`String`	Yes	Text content, including emoji.
`mentionedInfo`	`Object`	No	Mention (@) info for group messages. Not needed for direct channels. When sending via the server API, set `isMentioned` to `1` to mark the message as a mention; otherwise `mentionedInfo` is ignored.
`mentionedInfo.type`	`Int`	Yes	Mention type. `1`: mention all. `2`: mention specific users.
`mentionedInfo.userIdList`	`String[]`	No	List of mentioned user IDs. Required when `type` is `2`.
`mentionedInfo.mentionedContent`	`String`	No	Custom push content for mentions. Takes highest priority, overriding all default or custom `pushContent`.
`user`	`Object`	No	Sender user info embedded in the message. Recommended for live streaming scenarios only.
`user.id`	`String`	No	Sender's user ID.
`user.name`	`String`	No	Sender's nickname.
`user.portrait`	`String`	No	Sender's avatar URL.
`user.extra`	`String`	No	Custom extension data.
`extra`	`String`	No	Custom extension data.

Client defaults

Stored on the client
Counts as unread
Push supported by default
- Push title: sender's nickname (direct/system channels) or group name (group/community channels). Can be customized at send time.
- Push content: defaults to the message content. For group/community channels, prefixed with the sender's nickname.

Image message

ObjectName: RC:ImgMsg

Built into the client SDK. When sending via the server API, set the message type to RC:ImgMsg.

Content structure

JSON
{
  "content":"/9j/4AAQSkZJRgABAgAAZABkAAD",
  "localPath":"",
  "imageUri":"http://p1.cdn.com/fds78ruhi.jpg",
  "user":
  {
    "id":"4242",
    "name":"Robin",
    "portrait":"http://example.com/p1.png",
    "extra":"extra"
  },
  "extra":""
}

The image content consists of two parts:

Thumbnail: The content field contains the Base64-encoded thumbnail. When sending from the server, generate a thumbnail (recommended max 240 px on the longest edge), Base64-encode it, and place it in content. Strip any Data URI prefix (e.g., data:image/jpeg;base64,...) — use only the data portion.
Full image: The imageUri field contains the URL of the full-size image hosted on your file server.

Field	Type	Required	Description
`content`	`String`	Yes	Base64-encoded thumbnail. Recommended max 5 KB, absolute max 10 KB. Remove all `\r\n`, `\r`, and `\n` characters after encoding.
`name`	`String`	No	File name. If omitted, the client SDK generates a default name on download.
`localPath`	`String`	Yes	Local file path. Client-side only; do not set when sending from the server.
`imageUri`	`String`	Yes	URL of the full image on your file server.
`user`	`Object`	No	Sender user info. Recommended for live streaming only.
`user.id`	`String`	No	Sender's user ID.
`user.name`	`String`	No	Sender's nickname.
`user.portrait`	`String`	No	Sender's avatar URL.
`user.extra`	`String`	No	Custom extension data.
`extra`	`String`	No	Custom extension data.

Client defaults

Stored, counts as unread, push supported by default
Default push content: [Image]

Streaming message

ObjectName: RC:StreamMsg

When sending via the server API, set the message type to RC:StreamMsg and pass the content structure in the content field. Total message size must not exceed 128 KB (initial + continuation chunks combined).

Content structure

JSON
{
  "content": "# stream-content1",
  "complete": false,
  "messageUID": "xxxx",
  "seq": 1,
  "type": "markdown",
  "mentionedInfo": {
    "type": 2,
    "userIdList": ["123", "456"]
  },
  "user": {
    "id": "4242",
    "name": "Robin",
    "portrait": "http://example.com/p1.png",
    "extra": {"k1":"v1"}
  },
  "extra": {"k1":"v1"}
}

Field	Type	Required	Description
`content`	`String`	Yes	Stream data chunk. Total size (initial + continuation) must not exceed 128 KB.
`seq`	`Long`	Yes	Sequence number. Must be greater than 0, starting from 1, strictly incrementing and consecutive. Non-consecutive or duplicate sequence numbers may cause ordering issues.
`complete`	`Boolean`	Yes	Whether this chunk marks the end of the stream.
`completeReason`	`Int`	No	Custom completion reason code. Only effective when `complete` is `true`. Passed to the SDK with the initial packet.
`type`	`String`	No	Stream content type. Set on the initial chunk only. Default: `text`. Supported values: `text`, `markdown`, `html`.
`messageUID`	`String`	No	Streaming message ID. Omit for the initial chunk. Include for continuation chunks. If absent, the chunk is treated as the initial packet.
`user`	`Object`	No	Sender user info. Set on the initial chunk only. Recommended for passing bot extension info.
`user.id`	`String`	No	Sender's user ID.
`user.name`	`String`	No	Sender's nickname.
`user.portrait`	`String`	No	Sender's avatar URL.
`user.extra`	`JSON Object`	No	Bot extension metadata. Keys and values must be strings.
`mentionedInfo`	`Object`	No	Mention info for group messages. Set on the initial chunk only. When sending via the server API, set `isMentioned` to `1`.
`mentionedInfo.type`	`Int`	No	`1`: mention all. `2`: mention specific users.
`mentionedInfo.userIdList`	`String[]`	No	List of mentioned user IDs.
`extra`	`JSON Object`	No	Custom extension data. Set on the initial chunk only. Keys and values must be strings.

GIF message

ObjectName: RC:GIFMsg

Built into the client SDK. When sending via the server API, set the message type to RC:GIFMsg.

Content structure

JSON
{
    "gifDataSize":34563,
    "height":246,
    "localPath":"/var/mobile/.../GIF_53",
    "remoteUrl":"https://rongcloud-image.cn.ronghub.com/image_jpe64562665566.gif",
    "width":263,
    "user":
    {
      "id":"4242",
      "name":"Robin",
      "portrait":"http://example.com/p1.png",
      "extra":"extra"
    },
    "extra":""
}

Field	Type	Required	Description
`gifDataSize`	`Int`	Yes	GIF file size in bytes.
`name`	`String`	No	File name. If omitted, the client generates a default name.
`localPath`	`String`	Yes	Local file path. Client-side only.
`remoteUrl`	`String`	Yes	URL of the GIF on your file server.
`width`	`Int`	Yes	GIF width in pixels.
`height`	`Int`	Yes	GIF height in pixels.
`user`	`Object`	No	Sender user info.
`extra`	`String`	No	Custom extension data.

Client defaults

Stored, counts as unread, push supported by default
Default push content: [Image]

HD voice message

ObjectName: RC:HQVCMsg

Built into the client SDK. When sending via the server API, set the message type to RC:HQVCMsg.

Content structure

JSON
{
  "localPath":"/9j/4AAQSkZ/2wBaSiimB//9k=",
  "remoteUrl":"http://p1.cdn.com/fds78ruhi.aac",
  "duration":7,
  "user":
  {
    "id":"4242",
    "name":"Robin",
    "portrait":"http://example.com/p1.png",
    "extra":"extra"
  },
  "extra":""
}

Field	Type	Required	Description
`name`	`String`	No	File name. If omitted, the client generates a default name.
`localPath`	`String`	Yes	Local path of the AAC-encoded audio file. Client-side only.
`remoteUrl`	`String`	Yes	URL of the AAC audio file on your server. When sending via the server API, generate an AAC file and upload it to your file server.
`duration`	`Int`	Yes	Voice duration in seconds (max 60 seconds).
`user`	`Object`	No	Sender user info. Recommended for live streaming only.
`extra`	`String`	No	Custom extension data.

Client defaults

Stored, counts as unread, push supported by default
Default push content: [Voice]

tip

HD voice messages (RC:HQVCMsg) are recommended over standard voice messages. Audio data is stored on the server while the message body contains only a URL, removing the 128 KB message size limitation and providing higher audio quality. Max duration: 60 seconds.

File message

ObjectName: RC:FileMsg

Built into the client SDK. When sending via the server API, set the message type to RC:FileMsg.

Content structure

JSON
{
  "name":"file.txt",
  "size":190184,
  "type":"txt",
  "localPath":"",
  "fileUrl":"http://www.demo.com/am.ind",
  "user":
  {
    "id":"4242",
    "name":"Robin",
    "portrait":"http://example.com/p1.png",
    "extra":"extra"
  },
  "extra":""
}

Field	Type	Required	Description
`name`	`String`	No	File name.
`size`	`String`	Yes	File size in bytes.
`type`	`String`	Yes	File type/extension.
`localPath`	`String`	Yes	Local file path. Client-side only.
`fileUrl`	`String`	Yes	URL of the file on your server.
`user`	`Object`	No	Sender user info.
`extra`	`String`	No	Custom extension data.

Client defaults

Stored, counts as unread, push supported by default
Default push content: [File] filename

Short video message

ObjectName: RC:SightMsg

Built into the client SDK. When sending via the server API, set the message type to RC:SightMsg.

Content structure

JSON
{
  "sightUrl":"http://rongcloud...com/video...",
  "content":"/9j/4AAQSkZ/2wB...hDSaSiimB//9k=",
  "duration":2,
  "size":734320,
  "name":"video_xx.mp4",
  "user":
  {
    "id":"4242",
    "name":"Robin",
    "portrait":"http://example.com/p1.png",
    "extra":"extra"
  },
  "extra":"extra"
}

The content field contains the Base64-encoded first-frame thumbnail. When sending from the server, generate a thumbnail (max 240 px longest edge) and Base64-encode it. Strip any Data URI prefix.

Field	Type	Required	Description
`sightUrl`	`String`	Yes	URL of the video file on your server.
`content`	`String`	Yes	Base64-encoded first-frame thumbnail. Max 10 KB. Remove all `\r\n`, `\r`, `\n` after encoding.
`duration`	`Int`	Yes	Video duration in seconds. Default max recording: 10 seconds. Max supported: 2 minutes (contact sales to adjust).
`size`	`String`	Yes	Video file size in bytes.
`name`	`String`	Yes	Video file name. Format: MP4 (H.264+AAC).
`user`	`Object`	No	Sender user info.
`extra`	`String`	No	Custom extension data.

Client defaults

Stored, counts as unread, push supported by default
Default push content: [Video]

Location message

ObjectName: RC:LBSMsg

Built into the client SDK. When sending via the server API, set the message type to RC:LBSMsg.

Content structure

JSON
{
  "content":"bhZPzJXimRwrtvc=",
  "latitude":39.9139,
  "longitude":116.3917,
  "poi":"Nexconn Inc.",
  "user":
  {
    "id":"4242",
    "name":"Robin",
    "portrait":"http://example.com/p1.png",
    "extra":"extra"
  },
  "extra":""
}

Field	Type	Required	Description
`content`	`String`	Yes	Base64-encoded JPG thumbnail of the location. Remove all `\r\n`, `\r`, `\n` after encoding.
`latitude`	`Number`	Yes	Latitude.
`longitude`	`Number`	Yes	Longitude.
`poi`	`String`	Yes	Point of interest (location name).
`user`	`Object`	No	Sender user info.
`extra`	`String`	No	Custom extension data.

Client defaults

Stored, counts as unread, push supported by default
Default push content: [Location]

Quote message

ObjectName: RC:ReferenceMsg

tip

Typically used in direct and group channels. Send a quote message to reply to a specific message. Supported quoted types: text (RC:TxtMsg), image (RC:ImgMsg), file (RC:FileMsg). Quoted messages can themselves be quoted.

Built into the client SDK. When sending via the server API, set the message type to RC:ReferenceMsg.

Content structure

JSON
{
  "content":"This is a reply to the quoted message!",
  "referMsgUserId":"432432",
  "objName":"RC:TxtMsg",
  "referMsg":{
    "content":"Hello world!",
    "extra":""
  },
  "mentionedInfo":{
    "type":2,
    "userIdList":["123","456"],
    "mentionedContent":"Someone mentioned you"
  },
  "user":
  {
    "id":"4242",
    "name":"Robin",
    "portrait":"http://example.com/p1.png",
    "extra":"extra"
  },
  "extra":""
}

Field	Type	Required	Description
`content`	`String`	Yes	Text content of the reply, including emoji.
`referMsgUserId`	`String`	Yes	User ID of the sender of the quoted message.
`referMsg`	`Object`	Yes	Content structure of the quoted message (JSON).
`objName`	`String`	Yes	Message type of the quoted message. Supported: `RC:TxtMsg`, `RC:ImgMsg`, `RC:FileMsg`.
`mentionedInfo`	`Object`	No	Mention info. See the text message section for details.
`user`	`Object`	No	Sender user info.
`extra`	`String`	No	Custom extension data.

Client defaults

Stored, counts as unread, push supported by default
Default push content: the message content.

Combined forward message

ObjectName: RC:CombineMsg

Built into the client SDK. When sending via the server API, set the message type to RC:CombineMsg.

Content structure

JSON
{
  "localPath":"file:///storage/emulated/0/.../157829828.html",
  "remoteUrl":"https://rongcloud-html-cn.ronghub.com/text_plain__RC-2019-12-17_754_157130.html?e=1592Q=",
  "conversationType":1,
  "nameList":["Alice","Bob"],
  "summaryList":["Alice: Hello","Bob: Hi there","Bob: How are you","Alice: Good"]
}

Field	Type	Required	Description
`localPath`	`String`	No	Local HTML file path. Client-side only.
`remoteUrl`	`String`	Yes	Remote URL of the HTML file.
`conversationType`	`Int`	Yes	Channel type. `1`: direct. `3`: group.
`nameList`	`String[]`	Yes	Names of the first 4 message senders.
`summaryList`	`String[]`	Yes	Summaries of the first 4 messages.

Client defaults

Stored, counts as unread, push supported by default
Default push content: [Chat History]

Rich content message

ObjectName: RC:ImgTextMsg

Built into the client SDK. When sending via the server API, set the message type to RC:ImgTextMsg.

Content structure

JSON
{
  "title":"Title",
  "content":"Description",
  "imageUri":"http://p1.cdn.com/fds78ruhi.jpg",
  "url":"http://www.example.com",
  "user":
  {
    "id":"4242",
    "name":"Robin",
    "icon":"http://example.com/p1.png",
    "extra":"extra"
  },
  "extra":""
}

Field	Type	Required	Description
`title`	`String`	Yes	Message title.
`content`	`String`	Yes	Message text content.
`imageUri`	`String`	Yes	Image URL (120 x 120 px). Upload the image to your file server.
`url`	`String`	Yes	URL to open when the image is tapped.
`user`	`Object`	No	Sender user info.
`extra`	`String`	No	Custom extension data.

Client defaults

Stored, counts as unread, push supported by default
Default push content: [Rich Content]

How to send a mention (@) message

A mention message is not a separate message type. It uses the standard text or quote message type with an additional mentionedInfo object in the content.

Mention messages are supported in group and community channels for the following message types:

Text message (RC:TxtMsg)
Quote message (RC:ReferenceMsg)

`mentionedInfo` structure

Field	Type	Required	Description
`mentionedInfo`	`Object`	No	Mention info. When sending via the server API, set `isMentioned` to `1` to enable mention behavior.
`mentionedInfo.type`	`Int`	Yes	`1`: mention all members. `2`: mention specific users.
`mentionedInfo.userIdList`	`String[]`	No	User IDs to mention. Required when `type` is `2`.
`mentionedInfo.mentionedContent`	`String`	No	Custom push content for mentions. Takes highest priority, overriding all default or custom `pushContent`.

tip

When sending mention messages via the server API, set isMentioned to 1 to mark the message as a mention.

Text message with mention

JSON
{
  "content":"@Alice @Bob Hello World!",
  "mentionedInfo":{
    "type":2,
    "userIdList":["123","456"],
    "mentionedContent":"Someone mentioned you"
  },
  "extra":""
}

When sending from the server, manually include the mentioned users' display names in the content field text.

Quote message with mention

JSON
{
  "content":"@Tom This is a reply!",
  "referMsgUserId":"432432",
  "objName":"RC:TxtMsg",
  "referMsg":{
    "content":"Hello world!",
    "extra":""
  },
  "mentionedInfo":{
    "type":2,
    "userIdList":["tom1999"],
    "mentionedContent":"Someone mentioned you"
  },
  "extra":""
}

Chat SDK

Push Notification Service

Chat SDK

Call SDK

Call SDK

Chat Server

Text message​

Content structure​

Client defaults​

Image message​

Content structure​

Client defaults​

Streaming message​

Content structure​

GIF message​

Content structure​

Client defaults​

HD voice message​

Content structure​

Client defaults​

File message​

Content structure​

Client defaults​

Short video message​

Content structure​

Client defaults​

Location message​

Content structure​

Client defaults​

Quote message​

Content structure​

Client defaults​

Combined forward message​

Content structure​

Client defaults​

Rich content message​

Content structure​

Client defaults​

How to send a mention (@) message​

mentionedInfo structure​

Text message with mention​

Quote message with mention​

Text message

Content structure

Client defaults

Image message

Content structure

Client defaults

Streaming message

Content structure

GIF message

Content structure

Client defaults

HD voice message

Content structure

Client defaults

File message

Content structure

Client defaults

Short video message

Content structure

Client defaults

Location message

Content structure

Client defaults

Quote message

Content structure

Client defaults

Combined forward message

Content structure

Client defaults

Rich content message

Content structure

Client defaults

How to send a mention (@) message

`mentionedInfo` structure

Text message with mention

Quote message with mention