> ## 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.

# Integration

> Download links for the Windows SRTC C++ SDK (x86 and x64 packages), environment requirements, package layout, Visual Studio project configuration, and which runtime DLLs and plugins to ship. Read before adding the SDK to a Windows desktop project.

### Environment requirements

<Warning>
  **The SDK comes in two packages, x86 (Win32 / 32-bit) and x64 (64-bit), and the one you use must match your project's target platform.**
  Linking the x86 package into a 64-bit project (or the other way around) fails at link time with
  `fatal error LNK1112: module machine type 'x86' conflicts with target machine type 'x64'`.
</Warning>

* Target platform: Windows x86 (Win32 / 32-bit) or x64 (64-bit)—**choose the package that matches your project's target platform**
* Language: C++
* Runtime: the SDK package already ships the required VC++ runtime DLLs, so you **don't need** to install a runtime redistributable on the target machine

***

### Download the SDK

| Version | Architecture | Download |
| - | - | - |
| 2.1 | x86 (32-bit) | [rtc-win-sdk-2.1.zip](https://repo.open.seastart.cn/repository/vcs-releases/rtc-win-sdk-2.1.zip) |
| 2.1 | x64 (64-bit) | [rtc-win-sdk-x64-2.1.zip](https://repo.open.seastart.cn/repository/vcs-releases/rtc-win-sdk-x64-2.1.zip) |

When a new version is released, use the same naming pattern and replace the version number. The x64 package has an extra `-x64` segment **before** the version number:

```text theme={null}
https://repo.open.seastart.cn/repository/vcs-releases/rtc-win-sdk-<version>.zip
https://repo.open.seastart.cn/repository/vcs-releases/rtc-win-sdk-x64-<version>.zip
```

***

### Directory structure

After extracting you get the following (both packages have exactly the same structure, and the root directory inside is `rtc_dll/` in both):

```text theme={null}
rtc_dll/
├── include/          # Header files
│   ├── srtc.h
│   └── srtc_def.h
├── lib/
│   └── srtc.lib      # Import library, used at link time
└── bin/              # Runtime dependencies, all of which must ship with your program
    ├── srtc.dll      # SDK core
    ├── srtcLive.dll  # Capture / encoding and decoding / rendering
    ├── ...           # Media, codec, networking, and other dependencies
    └── plugin/       # Plugins and their xml configuration
```

<Warning>
  Both packages extract to a directory with the same name, so **don't extract them into the same directory where they overwrite each other**, and don't mix
  `lib` and `bin` across architectures (the x86 `srtc.lib` / `srtc.dll` are not the same binaries as the x64 ones).
</Warning>

<Note>
  The file list in the package (number and names of files) changes between versions, so don't pick files one by one by name.
  The AnyLive/OOK runtime isn't in the package; see the note under "Deploy runtime dependencies" below.
</Note>

***

### Project configuration

<Steps>
  <Step title="Add the include directory">
    Add `rtc_dll/include` to your project's additional include directories, and include the headers in your code:

    ```cpp theme={null}
    #include <srtc.h>
    #include <srtc_def.h>
    ```
  </Step>

  <Step title="Link the import library">
    Add `rtc_dll/lib` to the additional library directories and link `srtc.lib`.
  </Step>

  <Step title="Deploy runtime dependencies">
    Copy **everything** under `rtc_dll/bin` into the directory that contains your executable:

    ```text theme={null}
    YourAppDir/
    ├── YourApp.exe
    ├── srtc.dll
    ├── ...              ← the other DLLs under bin
    └── plugin/          ← keep the subdirectory structure unchanged
        ├── *.dll
        └── *.xml
    ```

    <Warning>
      Three things that are easy to miss:

      * **The DLL bitness must match `YourApp.exe`**: a 32-bit program uses `bin` from the x86 package, and a 64-bit program uses `bin` from the x64 package
      * **`plugin/` must stay a subdirectory**; don't flatten the DLLs inside it into the root directory
      * **Also copy the `.xml` configuration files under `plugin/`** (`conf.xml`, `cocktail_service.xml`,
        `linkmic_service.xml`). If they're missing, plugins fail to load, and features such as screen sharing don't work
    </Warning>

    <Warning>
      **Starting with 0.2.1-alpha.6, neither `rtc-win-sdk-2.1.zip` (x86) nor `rtc-win-sdk-x64-2.1.zip` (x64)
      includes the AnyLive/OOK runtime**:
      `AnyLiveMVSC.dll`, `libEGL.dll`, `libGLESv2.dll`, `libeay32.dll`, `ssleay32.dll`,
      `stlport.5.1.dll`, plus `anyLiveM.dll`, `cocktail_service.dll`, `libmm.dll`,
      `linkmic_service.dll`, `onvif_receiver.dll`, `transcoder.dll` under `plugin/`, and the three `.xml` files mentioned above.

      These files haven't changed, but you need to **obtain them separately** (for example, from the SMeeting Windows SDK package or the previous SRTC package).
      If they're missing, the program **fails to load them at runtime** rather than failing to compile—sending and receiving streams doesn't work after you join a channel.
      When you upgrade to this version, make sure these files are still in your distribution directory.
    </Warning>
  </Step>
</Steps>

<Note>
  The contents of the `bin` directory change between versions, so we recommend **copying it as a whole** rather than picking files one by one by name—picking files individually
  makes it easy to miss newly added dependencies when you upgrade the SDK.
</Note>

***

### Next steps

* [Quickstart](/en/rtc/windows/quickstart): initialize, join a channel, and send and receive audio and video
* [Key concepts](/en/rtc/key-concepts): the channel, user, and track model
* [Token and authentication](/en/rtc/token): the token for joining a channel is issued by your backend