> ## Documentation Index
> Fetch the complete documentation index at: https://docs.facebetter.net/llms.txt
> Use this file to discover all available pages before exploring further.

# Third-party Integration

> Wire Facebetter beauty into TRTC, Agora, LiveKit, and other Flutter video pipelines

SDK **2.0.0**. Flutter **only sets beauty parameters**. Live frames never enter Dart: call `FacebetterPlugin.processTexture` on the vendor SDK’s **native GL thread**, then write the output texture back.

```
Flutter (Dart)                              Native GL thread (iOS / Android)
FBEngine.create(externalContext: true)
engine.setSmoothing / setReshape / …  →     Vendor preprocess callback
await engine.setFilter                      FacebetterPlugin.processTexture(tex, w, h)
engine.dispose()                            Write back vendor textureId
```

## Shared contract

| Item        | Requirement                                                                                                   |
| ----------- | ------------------------------------------------------------------------------------------------------------- |
| Live engine | `externalContext: true` (default); `FBEngine.create` **before** enabling vendor custom preprocess             |
| Frames      | Native `FacebetterPlugin.processTexture` only; must run on the **current GL thread**                          |
| Stills      | Separate engine with `externalContext: false`; never mix with the live engine                                 |
| Input       | Prefer vendor **Texture2D / RGB (`GL_TEXTURE_2D`)**; convert OES / YUV first or change format per vendor docs |
| Tear-down   | Disable vendor preprocess / stop tracks, then `engine.dispose()`                                              |

Do **not** call `processFile` / `processImageBytes` / `processImageFile` / `processImageToUiImage` on the live engine.

```dart theme={null}
import 'package:facebetter_flutter/facebetter_flutter.dart';

FBEngine.setLogConfig(console: true, level: FBLogLevel.info);

final engine = await FBEngine.create(const FBEngineConfig(
  appId: 'your_app_id',
  appKey: 'your_app_key',
  externalContext: true,
  enableLandmarks: false,
));

engine.setSmoothing(0.8);
engine.setWhitening(0.5);
engine.setReshape(FBReshape.faceThin, 0.3);
engine.setLipstick(0.4);
await engine.setFilter(path: '/path/to/filter.fbd');

// Sliders can call sync setters directly:
// onChanged: (v) => engine.setSmoothing(v),
```

Credentials: [Subscription](/intro/enable-service), [Auth & License](/intro/license). Native texture rules: [Android · Third-party Integration](/android/third-party-integration), [iOS · Third-party Integration](/ios/third-party-integration).

|                   | Live engine             | Photo engine                                 |
| ----------------- | ----------------------- | -------------------------------------------- |
| `externalContext` | `true` (default)        | `false`                                      |
| Frames            | Native `processTexture` | Dart `processFile` / `processImageBytes` / … |
| Mixing            | No photo APIs           | Not for live / meeting preprocess            |

**Do not:** push pixels or texture ids from Dart every frame; call `processTexture` off the GL thread; treat `FBEngine` as a process-wide singleton.

***

## TRTC (Tencent)

Prerequisites: `tencent_trtc_cloud` (or native TRTC) and `facebetter_flutter: ^2.0.0`. When enabling custom preprocess, use **Texture2D + Texture buffer**, not YUV / PixelBuffer.

After creating the engine in Dart, enable custom process (API name may vary by plugin version):

```dart theme={null}
await trtcCloud.enableCustomVideoProcess(true);
```

### iOS — `onProcessVideoFrame`

```objc theme={null}
#import <facebetter_flutter/FacebetterPlugin.h>

- (uint32_t)onProcessVideoFrame:(TRTCVideoFrame *)srcFrame
                        dstFrame:(TRTCVideoFrame *)dstFrame {
  uint32_t out = [FacebetterPlugin processTexture:srcFrame.textureId
                                            width:srcFrame.width
                                           height:srcFrame.height];
  if (out != 0) {
    dstFrame.textureId = out;
  }
  return 0;
}
```

If you use `tencent_trtc_cloud`’s `ITXCustomBeautyProcesser`, keep **Texture2D / Texture** and call the same `processTexture` in the callback. Register the factory **after** `GeneratedPluginRegistrant.register(with:)`.

### Android — Kotlin

```kotlin theme={null}
import net.pixpark.facebetter.flutter.FacebetterPlugin

override fun onProcessVideoFrame(
    srcFrame: TRTCCloudDef.TRTCVideoFrame,
    dstFrame: TRTCCloudDef.TRTCVideoFrame,
): Int {
    val out = FacebetterPlugin.processTexture(
        srcFrame.texture.textureId,
        srcFrame.width,
        srcFrame.height,
    )
    if (out != 0) {
        dstFrame.texture.textureId = out
    }
    return 0
}
```

### Tear-down

```dart theme={null}
await trtcCloud.enableCustomVideoProcess(false);
engine.dispose();
```

***

## Agora

Same model as native: call `FacebetterPlugin.processTexture` inside the **iOS / Android** frame observer / custom preprocess callback; Dart only owns `FBEngine` parameters.

1. Dart: `FBEngine.create(externalContext: true)` and set beauty
2. Enable custom video processing or register a native observer per the Agora Flutter plugin (APIs vary by `agora_rtc_engine` version)
3. On a **`GL_TEXTURE_2D` textureId**, call `processTexture` and write back to the vendor frame

For OES / YUV-only callbacks, convert to Texture2D first, or see [Android](/android/third-party-integration#agora) / [iOS](/ios/third-party-integration#agora) (Flutter live path still prefers texture + `processTexture`).

Tear-down: unregister Agora preprocess, then `engine.dispose()`.

***

## LiveKit

Again: **Dart sets parameters, native processes textures**.

1. Create an `externalContext: true` engine in Dart
2. Obtain texture frames via LiveKit Flutter / a native custom capturer or video processor
3. Call `FacebetterPlugin.processTexture` on the **GL thread**, then feed the output back into the LiveKit track

Hook details vary by `livekit_client` and platform; texture rules: [Android · LiveKit](/android/third-party-integration#livekit), [iOS · LiveKit](/ios/third-party-integration#livekit).

***

## Related

* [Implement Beauty](/flutter/implement-beauty)
* [API Reference](/flutter/api-reference)
* [Android · Third-party Integration](/android/third-party-integration)
* [iOS · Third-party Integration](/ios/third-party-integration)