> ## Documentation Index
> Fetch the complete documentation index at: https://docs.stmlink.com/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> 对外开放的服务端接口有两组前缀，都用同一套鉴权：`/server/v1/...`（SRTC 与 SMeeting 的主接口）和 `/stm/srvapi/v1/...`（SMeeting 的用户体系，服务端极简对接会用到）。鉴权是 app_id + nonce + timestamp + signature 四个请求头，用 app_key 做 HMAC-SHA256 签名，只能从业务方自己的后端调用。除这两组前缀外的接口均为内部接口，不要建议客户调用。 Public server APIs use two path prefixes with the same authentication: `/server/v1/...` (the main APIs of both SRTC and SMeeting) and `/stm/srvapi/v1/...` (the SMeeting user system, used by server-side low-code integration). Authenticate with four request headers, app_id + nonce + timestamp + signature, where signature is HMAC-SHA256 keyed with app_key; call these APIs only from the customer's own backend. Any other path is internal: never suggest calling it.
> app_key 是服务端密钥，绝不能出现在客户端代码、前端配置或移动 App 里。客户端加入频道用的 token 必须由业务方后端签发后下发（SRTC 走 `/server/v1/channel/grant`，SMeeting 走 `/stm/srvapi/v1/member/grant`）。 app_key is a server-side secret and must never appear in client code, frontend config, or a mobile app. The token a client uses to join must be issued by the customer's backend and passed down to the client (SRTC: `/server/v1/channel/grant`; SMeeting: `/stm/srvapi/v1/member/grant`).
> SRTC 与 SMeeting 是上下两层不同的产品，术语不通用：SRTC 是音视频底座，说「频道 channel」「加入 / 退出」；SMeeting 建在 SRTC 之上，说「房间 room」「会议 meeting」「进入 / 退出」。回答时按用户所在的层用对应术语，不要把「房间」「会议」安到 SRTC 的接口上，也不要用「频道」「加入 / 离开」描述 SMeeting 的概念（接口标识符原样保留）。 SRTC and SMeeting are two separate layers with different terminology. SRTC is the audio/video foundation: it has channels, and users join and leave a channel. SMeeting is built on top of SRTC: it has rooms and meetings, and members enter and exit a meeting. Answer in the terms of the layer the user is working with: never apply "room" or "meeting" to SRTC APIs, and never describe SMeeting concepts in prose with "channel", "join", or "leave" (API identifiers such as `force_join` keep their literal names).
> 同一能力在各端 SDK 里的包名、类名、方法名并不相同。写示例代码时请使用文档中该端自己的 API，不要把一个端的写法套到另一个端上。苹果平台每个产品都有两套 SDK（Swift 原生与 Objective-C），两套 API 不能混用。 Package, class, and method names differ between platform SDKs for the same capability. In sample code, use the API documented for that platform; never carry one platform's code over to another. On Apple platforms each product ships two SDKs (native Swift and Objective-C) whose APIs must not be mixed.

# MeetingImEvent

> Receive Meeting IM connection, reconnection, raw message, call, meeting reminder, waiting room, and sub-meeting help events, registered through MeetingEngine.imEvent. Read this when you use enableIm() for out-of-meeting messages.

`MeetingImEvent` receives ongoing state and business messages that share the lifecycle of the IM connection in the Engine, and is registered through `MeetingEngine.imEvent`. You can extend `MeetingImSimpleEvent` and override only what you need.

## Usage notes

* The IM connection is independent of the current meeting; out-of-meeting messages such as meeting reminders, waiting room moves, and sub-meeting help requests are also dispatched through this interface.

* Call `enableIm()` first to establish the connection; an intentional disconnect caused by `disableIm()` or `release()` doesn't trigger `onImDisconnected()`.

* Callbacks stay on the actual IM source thread; switch to the main thread before updating the UI.

## Methods

### onImConnected(uid, sid)

```kotlin theme={null}
fun onImConnected(uid: String, sid: String)
```

Description: IM established its connection for the first time.

Parameters:

| Parameter | Description |
| - | - |
| `uid` | The current user's IM UID. |
| `sid` | Identifier of this IM session. |

Returns: None (`Unit`).

### onImDisconnected(reason, statusCode, message)

```kotlin theme={null}
fun onImDisconnected(reason: LeaveReason, statusCode: Int, message: String?)
```

Description: IM disconnected unintentionally.

Parameters:

| Parameter | Description |
| - | - |
| `reason` | Disconnect reason defined by SRTC. |
| `statusCode` | Underlying status code. |
| `message` | Nullable diagnostic information. |

Returns: None (`Unit`).

### onImReconnecting()

```kotlin theme={null}
fun onImReconnecting()
```

Description: IM started reconnecting automatically after a disconnect.

Parameters: None.

Returns: None (`Unit`).

### onImReconnected()

```kotlin theme={null}
fun onImReconnected()
```

Description: IM reconnected automatically.

Parameters: None.

Returns: None (`Unit`).

### onImMessage(uid, sid, name, action, content)

```kotlin theme={null}
fun onImMessage(
    uid: String,
    sid: String,
    name: String,
    action: String,
    content: String
)
```

Description: Receives a raw IM message that Meeting didn't parse into a dedicated business event.

Parameters:

| Parameter | Description |
| - | - |
| `uid` | Sender UID. |
| `sid` | Identifier of the session the message belongs to. |
| `name` | Sender nickname. |
| `action` | Message action name. |
| `content` | Raw message content. |

Returns: None (`Unit`).

### onCallReceived(uid, nickname, callingMsg)

```kotlin theme={null}
fun onCallReceived(
    uid: String,
    nickname: String,
    callingMsg: ImContent.CallingMsg
)
```

Description: Received a meeting call invitation.

Parameters:

| Parameter | Description |
| - | - |
| `uid` | Inviter UID. |
| `nickname` | Inviter nickname. |
| `callingMsg` | Target meeting ID, room number, and title. |

Returns: None (`Unit`).

### onMeetingRemind(uid, meetingRemind)

```kotlin theme={null}
fun onMeetingRemind(uid: String, meetingRemind: ImContent.MeetingRemind)
```

Description: Received a scheduled meeting reminder.

Parameters:

| Parameter | Description |
| - | - |
| `uid` | Message sender UID. |
| `meetingRemind` | Meeting, creator, and planned time information. |

Returns: None (`Unit`).

### onMoveOutWaitingRoom(uid, moveOutWaitingRoom)

```kotlin theme={null}
fun onMoveOutWaitingRoom(
    uid: String,
    moveOutWaitingRoom: ImContent.MoveOutWaitingRoom
)
```

Description: The host moved the current user from the waiting room into the meeting.

Parameters:

| Parameter | Description |
| - | - |
| `uid` | Message sender UID. |
| `moveOutWaitingRoom` | Target meeting ID and title. |

Returns: None (`Unit`).

### onUserHelpSubMeeting(uid, userHelpSubMeeting)

```kotlin theme={null}
fun onUserHelpSubMeeting(
    uid: String,
    userHelpSubMeeting: ImContent.UserHelpSubMeeting
)
```

Description: Received a help request from a sub-meeting member.

Parameters:

| Parameter | Description |
| - | - |
| `uid` | UID of the member asking for help. |
| `userHelpSubMeeting` | Main meeting and sub-meeting information, including the sub-meeting title. |

Returns: None (`Unit`).