> ## 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.

# SMeetingEngine

> API reference for SMeetingEngine, the single entry point of the SMeeting Swift SDK: initialization, properties, login and logout, creating and querying meetings, entering and exiting, state queries, member actions, out-of-meeting messages, and virtual background. Look up signatures and throws here.

`SMeetingEngine` is the SDK's only public entry point. Create only one instance per app and hold it globally.

This page covers initialization, authentication, meeting management, entering and exiting meetings, state queries, in-meeting member actions, and out-of-meeting messages. For media APIs, see [Media control](/en/meeting/swift/api-reference/media-control); for devices, see [Devices](/en/meeting/swift/api-reference/devices); for host and management APIs, see [Meeting management](/en/meeting/swift/api-reference/admin-actions).

***

### Initialization

#### `init(logLevel:)`

Creates an SDK instance.

```swift theme={null}
let meeting = SMeetingEngine(logLevel: .info)
```

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `logLevel` | `LogLevel` | No | Log level, default `.warning`. Options: `.verbose`, `.debug`, `.info`, `.warning`, `.error`, `.off` |

***

### Properties

#### `version`

```swift theme={null}
let v = SMeetingEngine.version
```

The SDK version number, of type `String`; a static property.

#### `srtc`

The underlying RTC instance, of type `SRTCEngine`. An escape hatch for when the meeting layer's APIs aren't enough.

```swift theme={null}
meeting.srtc.logLevel = .debug
```

> Always use this instance; don't create a second SRTCEngine yourself—the meeting and the underlying layer share the same instance, and creating another one leads to split state, duplicate message connections, and devices being taken over.

#### `delegates`

The collection of event delegates, of type `MulticastDelegate<SMeetingDelegate>`. A weak-reference multicast that supports multiple observers.

```swift theme={null}
meeting.delegates.add(delegate: self)
meeting.delegates.remove(delegate: self)
```

#### `currentUserId`

The ID of the currently logged-in user, of type `String?`; `nil` when not logged in.

#### `isInRoom`

Whether you're currently in a meeting, of type `Bool`.

#### `cameraTrack` / `screenTrack` / `mcuTrack`

The local camera track (`LocalCameraTrack?`), the local screen sharing track (`LocalScreenTrack?`), and the remote composite track (`RemoteVideoTrack?`). Each is `nil` when the corresponding capability isn't on.

***

### Authentication

#### `login(token:)`

Logs in to the conferencing SDK. You can call the other APIs only after logging in.

```swift theme={null}
try await meeting.login(token: token)
```

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `token` | `String` | Yes | The meeting token issued by your backend |

**Returns:** None

**Throws:**

* `SMeetingError.tokenInvalid`—the token format can't be parsed
* `SMeetingError.tokenExpired`—the token has expired
* `SMeetingError.apiError(code:message:)`—the server rejected the login
* `SMeetingError.networkError(_:)`

***

#### `logout()`

Logs out. If still in a meeting, it first exits the meeting automatically, and it disables the out-of-meeting message path.

```swift theme={null}
await meeting.logout()
```

**Returns:** None; doesn't throw.

***

### Meeting management (before the meeting)

The following APIs require only login, not being in a meeting.

#### `createRoom(_:)`

Creates a meeting.

```swift theme={null}
var req = MeetingCreateReq(title: "Weekly project sync", meetingMode: .normal)
req.meetingType = .instant
let (roomNo, meetingId) = try await meeting.createRoom(req)
```

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `req` | `MeetingCreateReq` | Yes | Creation parameters; for fields, see [Types](/en/meeting/swift/types#meetingcreatereq) |

**Returns:** `(roomNo: String, meetingId: String)`

**Throws:** `SMeetingError.notLoggedIn`, `SMeetingError.apiError(code:message:)`

> If `meetingType` isn't set explicitly, an instant meeting is created.

***

#### `updateRoom(meetingId:req:)`

Updates a meeting (before the meeting).

```swift theme={null}
try await meeting.updateRoom(meetingId: meetingId, req: req)
```

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `meetingId` | `String` | Yes | ID of the meeting to update |
| `req` | `MeetingCreateReq` | Yes | The new meeting parameters |

**Returns:** None

**Throws:** `SMeetingError.notLoggedIn`, `SMeetingError.apiError(code:message:)`

***

#### `cancelRoom(meetingId:)`

Cancels a meeting.

```swift theme={null}
try await meeting.cancelRoom(meetingId: meetingId)
```

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `meetingId` | `String` | Yes | Meeting ID |

**Returns:** None

**Throws:** `SMeetingError.notLoggedIn`, `SMeetingError.apiError(code:message:)`

***

#### `detailRoom(meetingId:roomNo:)`

Gets meeting details; provide one of the two parameters.

```swift theme={null}
let info = try await meeting.detailRoom(roomNo: "10000001")
```

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `meetingId` | `String?` | No | Meeting ID |
| `roomNo` | `String?` | No | Room number |

**Returns:** `MeetingInfo`

**Throws:** `SMeetingError.notLoggedIn`, `SMeetingError.apiError(code:message:)`

***

#### `attendeeRoom(page:)`

Meetings you need to attend (not started yet or in progress).

```swift theme={null}
let result = try await meeting.attendeeRoom()
```

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `page` | `PageParam` | No | Pagination parameters; defaults to page 1 with 20 items per page |

**Returns:** `PageResult<MeetingInfo>`

**Throws:** `SMeetingError.notLoggedIn`, `SMeetingError.apiError(code:message:)`

***

#### `attendedRoom(page:)`

Past meetings. Parameters and return value are the same as `attendeeRoom(page:)`.

***

#### `roomParticipant(meetingId:page:perPage:)`

Attendance records of a meeting.

```swift theme={null}
let result = try await meeting.roomParticipant(meetingId: meetingId)
```

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `meetingId` | `String` | Yes | Meeting ID |
| `page` | `Int` | No | Page number, default `1` |
| `perPage` | `Int` | No | Items per page, default `20` |

**Returns:** `PageResult<ParticipantInfo>`

**Throws:** `SMeetingError.notLoggedIn`, `SMeetingError.apiError(code:message:)`

***

### Enter / exit a meeting

#### `enterRoom(_:)`

Enters a meeting.

```swift theme={null}
var req = MeetingEnterReq(nickname: "Alice", roomNo: "10000001")
req.password = "123456"
try await meeting.enterRoom(req)
```

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `req` | `MeetingEnterReq` | Yes | Parameters for entering the meeting; provide either `meetingId` or `roomNo` |

**Returns:** None

**Throws:**

* `SMeetingError.notLoggedIn`
* `SMeetingError.alreadyInMeeting`—already in a meeting; call `exitRoom()` first
* `SMeetingError.apiError(code:message:)`—wrong password, meeting doesn't exist, entry restricted, and so on
* Errors thrown when the underlying connection fails to be set up

On success, the SDK subscribes to remote audio automatically; video is subscribed on demand.

***

#### `exitRoom()`

Exits the current meeting; the login state is kept.

```swift theme={null}
await meeting.exitRoom()
```

**Returns:** None; doesn't throw. Calling it when not in a meeting is safely ignored.

***

### State queries

#### `getRoomInfo()`

**Returns:** `RoomInfo?`; `nil` when not in a meeting.

#### `getWhiteBoard()`

**Returns:** `String?`, the whiteboard URL of the current meeting; `nil` if there is none.

#### `getUserInfo(_:)`

```swift theme={null}
let user = try meeting.getUserInfo(uid)
```

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `uid` | `String` | Yes | Member ID |

**Returns:** `MeetingUserInfo`

**Throws:** `SMeetingError.notInMeeting`, `SMeetingError.internalError(_:)` (no such member in the meeting)

#### `getUsersInfo()`

**Returns:** `[String: MeetingUserInfo]`, a map from uid to member; an empty dictionary when not in a meeting.

#### `getUsersInfoList()`

**Returns:** `[MeetingUserInfo]`; an empty array when not in a meeting.

#### `getRemoteVideoTrack(uid:desc:)`

Looks up the track object of a given video track of a member, **without subscribing**.

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `uid` | `String` | Yes | Member ID |
| `desc` | `TrackDesc` | No | Track description, default `.cameraBig` |

**Returns:** `Track?`; `nil` when the member doesn't exist or hasn't published that track.

***

### In-meeting member actions

The following APIs all require being in a meeting; otherwise they throw `SMeetingError.notInMeeting`. When the server rejects the call, they throw `SMeetingError.apiError(code:message:)`.

#### `updateName(_:)`

Changes your own in-meeting display name.

```swift theme={null}
try await meeting.updateName("New nickname")
```

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `name` | `String` | Yes | New nickname |

***

#### `sendRoomChatMessage(_:type:targetId:)`

Sends an in-meeting chat message.

```swift theme={null}
try await meeting.sendRoomChatMessage("Hi everyone")
try await meeting.sendRoomChatMessage(url, type: .pic, targetId: uid)
```

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `msg` | `String` | Yes | Message content |
| `type` | `ChatMsgType` | No | Message type, default `.text` |
| `targetId` | `String?` | No | Target member for a private message; omit to send to everyone |

***

#### `sendRoomCustomMessage(_:targetId:)`

Sends a custom message of your own.

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `content` | `String` | Yes | Message content, usually your own JSON |
| `targetId` | `String?` | No | Target member for a private message; omit to send to everyone |

***

#### `requestHandup(_:)` / `cancelHandup(_:)`

Raises a hand or cancels it.

```swift theme={null}
try await meeting.requestHandup(.mic)
try await meeting.cancelHandup(.mic)
```

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `code` | `HandupType` | Yes | `.mic` / `.camera` / `.chat` / `.share` |

***

#### `rejectOpenMic(adminUid:)` / `rejectOpenCamera(adminUid:)`

Declines the host's request to turn on the microphone / camera.

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `adminUid` | `String?` | No | ID of the host who sent the request, taken from `opUid` of the corresponding event |

***

#### `rollCallAnswer(rollCallUserId:)`

Answers a roll call.

| Parameter | Type | Required | Description |
| - | - | :-: | - |
| `rollCallUserId` | `String` | Yes | Pass `RollCallNamedEventData.id` directly. Note that it's not `.sid` (that's the uid of the host who started the roll call) |

**Throws:** `SMeetingError.notLoggedIn`, `SMeetingError.apiError(code:message:)`

***

### Out-of-meeting messages

#### `enableIm()`

Enables the out-of-meeting message path.

```swift theme={null}
try await meeting.enableIm()
```

**Returns:** None

**Throws:** `SMeetingError.notLoggedIn`, `SMeetingError.apiError(code:message:)`, and underlying errors when the connection fails to be set up

#### `disableIm()`

Disables the out-of-meeting message path.

```swift theme={null}
await meeting.disableIm()
```

**Returns:** None; doesn't throw. `logout()` calls it internally.

***

### Virtual background

This is a **device-level setting** (it applies to the single shared camera capture pipeline in the process), and it applies to all meetings at once. After switching cameras, turning the camera off and on again, or reconnecting after a disconnect during the meeting, your app doesn't need to apply it again. For usage and tuning, see [Virtual background](/en/meeting/swift/advanced/virtual-background).

| Member | Signature | Description |
| - | - | - |
| Install | `installVirtualBackground(modelPath: String? = nil) throws` | Loads the model + creates the inference session, taking hundreds of milliseconds; don't call it on the main thread / capture thread; `nil` uses the built-in model |
| Uninstall | `uninstallVirtualBackground()` | Releases the inference session and buffers; doesn't clear effect parameters |
| Master switch | `enableVirtualBackground(_ enabled: Bool) throws` | When off, frames pass straight through with zero overhead and no inference runs |
| Switch state | `isVirtualBackgroundEnabled: Bool` | Read-only |
| Background blur | `setVirtualBackgroundBlur(level: Int)` | `level` ranges from 1 to 10, default 5; out-of-range values are clamped to the boundary |
| Background replacement | `setVirtualBackgroundImage(_ image: SRTCNativeImage?)` | Cropped to cover without stretching; `nil` falls back to blur |
| Inference interval | `setVirtualBackgroundInferenceInterval(_ interval: Int)` | Runs segmentation every N frames (compositing still runs every frame); default 1 |
| Mask sync | `setVirtualBackgroundMaskSync(_ enabled: Bool)` | Default `false`; when `interval` is 1, the switch makes no difference |
| Instance | `virtualBackground: SRTCVirtualBackground` | Read-only state and dropped-frame count for diagnostics |

**Throws:** `SRTCError.virtualBackgroundAlreadyInstalled`, `.virtualBackgroundNotInstalled`, `.virtualBackgroundModelNotFound(String)`, `.virtualBackgroundSessionFailed(String)`

This group forwards to the audio and video layer, and the meeting layer doesn't keep a separate copy of the state, so it's equivalent to calling through `meeting.srtc` directly; we recommend using the meeting layer's methods.

***

### Related pages

* [Virtual background](/en/meeting/swift/advanced/virtual-background)
* [Media control APIs](/en/meeting/swift/api-reference/media-control)
* [Device APIs](/en/meeting/swift/api-reference/devices)
* [Meeting management APIs](/en/meeting/swift/api-reference/admin-actions)
* [Events](/en/meeting/swift/events)
* [Types](/en/meeting/swift/types)