> ## 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.

# Components and architecture

> Which services make up a self-hosted SRTC / SMeeting deployment, which are required or optional, install order, supported OSes and databases, and single- vs. multi-server layouts. Read before planning a deployment and preparing servers.

Our platform can be deployed entirely on the customer's own servers, with **fully offline installation** and no dependency on the internet. This page explains what an environment consists of,
to help you prepare servers and align the plan with the customer's network and security teams. For opening ports, see [Network and port requirements](https://docs.stmlink.com/en/product/deploy/ports.md).

***

## Overall architecture

```mermaid theme={null}
flowchart TB
    subgraph CLIENT["Clients"]
        A["App / desktop / web / Mini Program"]
        D["Conferencing endpoints / cameras"]
    end

    subgraph SVR["Servers"]
        N["Unified entry point<br/>HTTPS + signaling"]
        subgraph CORE["Core services"]
            RTC["Audio and video service<br/>(incl. media forwarding SFU)"]
            MTG["Meeting service"]
            ST["Unified storage"]
        end
        subgraph EXT["Extension services (optional)"]
            MCU["MCU<br/>cloud recording / video compositing"]
            GW["Device gateway"]
            TR["Voice recording gateway"]
            ASR["Speech recognition gateway"]
            LOG["Log center"]
        end
        subgraph BASE["Base components"]
            DB["Database"]
            RD["Redis"]
            MQ["MQTT signaling"]
        end
    end

    A --> N
    A -. "Audio/video (UDP)" .-> RTC
    D --> GW
    N --> RTC
    N --> MTG
    RTC --> BASE
    MTG --> BASE
    MCU --> RTC
    GW --> RTC
    TR --> RTC
    ASR --> RTC
```

***

## Services

### Required

| Service | Role |
| - | - |
| Unified entry point (Nginx) | The external HTTPS entry point for APIs, the admin console, the web client, and signaling |
| Audio and video service | Channels, users, permissions, and media forwarding (SFU). The admin console is also here |
| Unified storage | Storage gateway for video recordings, audio recordings, and meeting attachments; works with local disks or object storage |
| Database | PostgreSQL |
| Redis | Caching and state |
| MQTT signaling | Real-time signaling such as meeting control messages and member status |

### Optional

| Service | When to install |
| - | - |
| Meeting service | When using SMeeting meeting features (not needed if you use only SRTC audio and video) |
| MCU | When you need **cloud recording**, **video compositing**, **re-streaming**, or **connected SIP / H.323 endpoints need to see the meeting's video** |
| Device gateway | When connecting SIP / H.323 endpoints, GB28181 cameras, or RTSP streams; see [Room Connector](https://docs.stmlink.com/en/product/device-access/overview.md) |
| Voice recording gateway | When you need per-speaker segmented recording (audit trails for push-to-talk and dispatch) |
| Speech recognition gateway | When you need live captions or meeting minutes; the recognition engine is deployed separately |
| Log center | When you need to view client logs and call quality data centrally |
| Monitoring center | When you need to monitor server and service status |

***

## Installation

* Deliverables are an **offline installation package** (with all service images) and a **web installer**
* Run the installer on the server, open the installation page in a browser, and install **base components → core services → extension services** in order; each service is a card—fill in the parameters and install
* The installer also handles later **upgrades**: import the new version's images and upgrade with one click on the page, with configuration merged automatically
* After installation, import the **license file**; meetings work only once it's imported

> [!NOTE]
>
> Close the installer once installation is done. It has permission to change configuration and restart services, so **never expose it externally**.

***

## Environment requirements

| Item | Requirement |
| - | - |
| CPU architecture | x86\_64 (amd64) and ARM64 |
| Operating system | Mainstream 64-bit Linux distributions; confirm specific versions with us |
| Runtime | Docker (the installer can install it with one click, no internet needed) |
| Database | PostgreSQL (bundled) |
| Certificate | HTTPS certificate for the external domain (with the full certificate chain); on internal-only networks without a formal certificate you can use a self-signed one, but every client must trust the corresponding root certificate |

Server sizing depends heavily on concurrency, whether you record, and the number of devices; contact us for an assessment based on your actual scenario.

***

## Deployment topologies

| Topology | Description | Best for |
| - | - | - |
| **Single server** | All services on one server | Testing, small to medium scale |
| **Split servers** | Extension services such as the MCU and device gateway deployed on separate servers | Heavy recording or many connected devices that need isolated resources |
| **Multiple media nodes** | Several servers each run a media forwarding node, with users assigned by load or proximity | High concurrency, multiple regions; see [Multiple nodes and nearest access](https://docs.stmlink.com/en/product/deploy/multi-node.md) |
| **Internal network + public internet planes** | One platform serves users on the internal network and the public internet at the same time | Government and enterprise internal networks plus remote work from the public internet; see [Internal network and public internet](https://docs.stmlink.com/en/product/deploy/networks.md) |
| **Across a cross-domain solution** | The platform is on the internal network, and public-internet users connect through a cross-domain solution (CDS) | Strongly isolated networks for public security, procuratorates, courts, and government agencies; see [Access across a cross-domain solution](https://docs.stmlink.com/en/product/deploy/optical-gap.md) |


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