> ## 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.

# Meeting materials

> Upload and download meeting materials with the SMeeting Swift SDK using presigned URLs: get an upload URL, PUT the file directly, register it as a resource, get a signed download URL, and query the resource list and folders. Read when your meetings need attachments, background images, or avatars.

### Overview

Meeting materials (attachments, background images, avatars, and so on) use a "presigned direct upload" model:

```text theme={null}
Ask the SDK for an upload URL  →  Your app PUTs the file directly to that URL  →  Register the resKey as a resource
```

The file itself doesn't go through the SDK; the SDK only issues URLs and maintains resource records.

***

### Upload

#### 1. Get an upload URL

```swift theme={null}
let (url, key, ext) = try await meeting.presignedPutObject(
    type: .attach,
    meetingId: meetingId,
    ext: "pdf"
)
```

`PresignedPutObjectType` values:

| Enum value | Raw value | Purpose |
| - | - | - |
| `.attach` | `attach` | Meeting attachments |
| `.background` | `background` | Meeting background images |
| `.user` | `user` | User-related resources, such as avatars |

The returned `key` is the resource key of this file; you use it for both registering and downloading later.

#### 2. Upload the file directly

```swift theme={null}
var request = URLRequest(url: URL(string: url)!)
request.httpMethod = "PUT"
let (_, response) = try await URLSession.shared.upload(for: request, from: fileData)
```

#### 3. Register the resource

```swift theme={null}
var req = ResourceCreateReq(resName: "Meeting materials.pdf", resType: "pdf")
req.meetingId = meetingId
req.resKey = key
try await meeting.resourcesCreate(req: req)
```

`ResourceCreateReq` also has a `parentId` field for putting the resource into a folder.

***

### Download

First get a signed download URL, then download it yourself:

```swift theme={null}
// By resource ID
let url = try await meeting.presignedGetObject(id: resource.id)

// Or by resource key (such as the vodKey of a recording file)
let url = try await meeting.presignedGetObject(resKey: detail.vodKey)
```

Provide one of the two parameters.

***

### Query the resource list

```swift theme={null}
var req = ResourceListReq(page: 1, perPage: 20)
req.meetingId = meetingId
req.resType = "pdf"

let page = try await meeting.resourcesList(req: req)
for item in page.data {
    print(item.resName, item.resSize)
}
```

Filters supported by `ResourceListReq`: `parentId` (folder), `meetingId`, `resName` (fuzzy name match), `resType`.

In the returned `ResourceInfo`, `isFolder` set to `true` means this is a folder node; you can use its `id` as the `parentId` for querying the next level.

***

### Related pages

* [Recording and composite layout](/en/meeting/swift/advanced/recording)
* [API reference - Meeting management](/en/meeting/swift/api-reference/admin-actions)