> ## 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.

# Changelog

> Release history of the SRTC Web SDK (@seastart/srtc-web-sdk), from v0.4.4 to the latest v0.6.x: multi-channel with join returning Channel, processors and noise suppression plugins, local recording, simulcast, and fixes. Read before upgrading.

### Latest version

Check the latest version on npm:

```bash theme={null}
npm info @seastart/srtc-web-sdk version
```

***

### Release history

> The changelog is still being filled in. For details on changes in a specific version, contact technical support.

### Recent updates

### v0.6.3 - 2026-09-23

* fix: local audio mixing now outputs directly through AudioContext, fixing dull received audio on Web
* fix: the hidden audio elements used internally by mixing to activate remote tracks are now muted and kept referenced, preventing mixing from occasionally going silent after they were garbage-collected
* feat: RemoteAudioTrack now has setJitterBufferTarget / getJitterBufferTarget (previously only video tracks supported them)

### v0.6.2 - 2026-09-02

* fix(channel): publishing the same desc again now throws directly, preventing ghost tracks that can't be turned off
* fix: default channel detection no longer relies only on object identity, preventing all events from being lost when the instance is wrapped in a reactive proxy
* fix: business errors are no longer swallowed as "call canceled", and reconnection can recover on its own when capacity is insufficient

### v0.6.1 - 2026-08-06

* fix: events lost on remote tracks subscribed directly through Channel (muted/ended/pip, etc. not notified); channel.subscribeRemote\* now returns platform types (RemoteVideoTrack, etc.), so no type assertions are needed

### v0.6.0 - 2026-08-05

* feat!: engine + multi-channel model: join returns Channel, supports joining multiple channels at once

### v0.5.7 - 2026-07-21

* feat: when the camera is off in local recording, a round avatar is shown in the center of the tile; if the avatar fails to load or cross-origin access is refused, it falls back to a gray circle with the nickname's first letter

### v0.5.6 - 2026-06-16

* feat: video supports front camera mirroring, on by default for the front camera and adjustable by the user
* feat: DeepFilterNet noise suppression plugin

### v0.5.4 - 2026-06-03

* feat: added the audio/video processor plugin mechanism
* feat: added the wasm noise suppression plugin

### v0.5.3 - 2026-05-08

* feat: add local composite recorder (47a20b0)
* chore: optimized default screen sharing configuration (f079eeb)

### v0.5.1 - 2026-04-27

* fix: video freezes (b7a36c2)
* feat: RemoteVideoTrack supports setting jitterBufferTarget (jitter buffer target delay) (6aed177)

### v0.5.0 - 2026-04-23

* feat: the seastart engine now receives quality reports sent by the server
* feat: type-safe rework of the channel event system, supporting discriminated unions and automatic type narrowing
* feat: the seastart engine now supports active speakers (users who are speaking)
* feat: added adaptive streaming, which switches simulcast layers automatically based on play window state and supports SFU downlink layer switch notifications and active layer switch requests

### v0.4.4 - 2026-04-18

* feat: simulcast support and optimized SFU subscription layer switching (781f520)

* Web video tracks gain picture-in-picture and separate window capabilities: `enterPictureInPicture`, `exitPictureInPicture`, `popOutToWindow`, `closePopOutWindow`

* New channel events: `TRACK_PIP_ENTER`, `TRACK_PIP_EXIT`, `TRACK_POPOUT_OPEN`, `TRACK_POPOUT_CLOSE`

* `PipOptions` and `PopOutOptions` gain the `hideOriginView` option, defaulting to `true`