---
title: FxPrincipalAPI
framework: Professional Video Applications
role: symbol
role_heading: Protocol
platforms: [fxplug 4.1+]
path: professional_video_applications/fxprincipalapi
---

# FxPrincipalAPI

A protocol that provides an interface that the host application implements to retrieve an XPC proxy object for communicating with its XPC.

## Declaration

```swift
protocol FxPrincipalAPI
```

## Topics

### Getting XPC Proxy Objects

- [servicePrincipal()](professional_video_applications/fxprincipalapi/serviceprincipal().md)

## See Also

### Services

- [FxPrincipal](professional_video_applications/fxprincipal.md)
- [FxPrincipalDelegate](professional_video_applications/fxprincipaldelegate.md)