> ## 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.

# LogUtil

> Android SDK logging utility: reuse LogUtil to write leveled logs (v/d/i/w/e) and structured marker, format, and metric logs into the same local log file as the SDK's own logs. Read when you want app logs collected alongside SDK logs for debugging.

`LogUtil` is the SDK's logging utility (a Kotlin `object` singleton). You can reuse it to write leveled logs, which go into the same local file as the SDK's internal logs (when `enableLocalLog = true` in `RTCEngine.create`), making debugging and troubleshooting easier. The log file path is determined by `localLogPath` in `create(...)`.

The `tag` parameter of every leveled method defaults to `LogUtil.TAG`; you can pass a custom tag.

## Leveled logs

### v(msg, tag)

```kotlin theme={null}
fun v(msg: String, tag: String = TAG)
```

Description: Writes a Verbose-level log.\
Parameters:

* `msg`: `String`, the log content.
* `tag`: `String`, the log tag; defaults to `LogUtil.TAG`.

Returns: None (`Unit`).

### d(msg, tag)

```kotlin theme={null}
fun d(msg: String, tag: String = TAG)
```

Description: Writes a Debug-level log.\
Parameters: Same as above.\
Returns: None (`Unit`).

### i(msg, tag)

```kotlin theme={null}
fun i(msg: String, tag: String = TAG)
```

Description: Writes an Info-level log.\
Parameters: Same as above.\
Returns: None (`Unit`).

### w(msg, tag)

```kotlin theme={null}
fun w(msg: String, tag: String = TAG)
```

Description: Writes a Warn-level log.\
Parameters: Same as above.\
Returns: None (`Unit`).

### e(msg, tag)

```kotlin theme={null}
fun e(msg: String, tag: String = TAG)
```

Description: Writes an Error-level log.\
Parameters: Same as above.\
Returns: None (`Unit`).

### e(t, tag)

```kotlin theme={null}
fun e(t: Throwable, tag: String = TAG)
```

Description: Writes an Error-level log with an exception stack trace.\
Parameters:

* `t`: `Throwable`, the exception object; the full stack trace is expanded internally.
* `tag`: `String`, the log tag; defaults to `LogUtil.TAG`.

Returns: None (`Unit`).

## Structured logs (advanced)

### addMarkerLog(content)

```kotlin theme={null}
fun addMarkerLog(content: String)
```

Description: Writes a marker log, commonly used to mark key business points in the log stream for easier tracing.\
Parameters:

* `content`: `String`, the marker content.

Returns: None (`Unit`).

### addFormatLog(type, attr, body, level)

```kotlin theme={null}
fun addFormatLog(type: String, attr: Any?, body: String?, level: LoggerLevel = LoggerLevel.Info)
```

Description: Writes a formatted log; `attr` is serialized to JSON and attached to the log.\
Parameters:

* `type`: `String`, the log type identifier.
* `attr`: `Any?`, the attached attribute object; `null` means no attributes.
* `body`: `String?`, the log body; can be `null`.
* `level`: `LoggerLevel`, the log level; defaults to `LoggerLevel.Info`.

Returns: None (`Unit`).

### addMetricLog(metricType, metricInfo)

```kotlin theme={null}
fun addMetricLog(metricType: String, metricInfo: MetricItem)
```

Description: Writes a metric log; `metricInfo` is serialized to JSON.\
Parameters:

* `metricType`: `String`, the metric type identifier.
* `metricInfo`: `MetricItem`, the metric data object.

Returns: None (`Unit`).