> ## 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 Python SDK (PyPI package srtc): what each version added or changed, and whether you can upgrade directly. Read before upgrading.

### \[0.1.1] - 2026.09.26

#### Changed

* The PyPI project page now has bilingual Chinese and English descriptions
* Installation notes added: on Linux with glibc below 2.28 (such as CentOS 7), pin the dependency version with `pip install srtc "av>=12,<14"`

<Note>
  No changes to the API or behavior; you can upgrade directly from 0.1.0.
</Note>

### \[0.1.0] - 2026.09.26

First release, published to PyPI: `pip install srtc`.

#### Added

* Join / leave a channel, query users, tracks, and channel info, and auto-subscribe or subscribe manually
* Remote audio decoded to PCM in a specified format, with DTX silence frames filled in based on RTP timestamps for a continuous timeline
* Audio publishing: write PCM at any sample rate, and the SDK resamples, encodes, and sends it at real-time pace; `clear()` supports barge-in interruption, and `write()` has built-in backpressure
* Remote video reception, optionally decoded to RGB images, with key frames requested automatically on decoding errors
* Active speaker, network quality, layer switch, and custom message events; disconnect reasons distinguish being removed from the channel / replaced by another session with the same uid / the channel being destroyed
* Two usage styles: frame-by-frame consumption with `async for`, and `ChannelHandler` callbacks
* Built-in pipecat transport (`pip install "srtc[pipecat]"`)
* Platforms: Linux x86\_64 / aarch64, macOS Apple Silicon, Windows x64, Python 3.10+

<Note>
  This version only supports receiving video, not publishing video.
</Note>