---
title: Communicating with the plug-in state
framework: professional-video-applications
role: article
path: professional-video-applications/communicating-with-the-plug-in-state
---

# Communicating with the plug-in state

## Communicating with the plug-in state

Communicating with the plug-in state Prepare the necessary information, such as parameter values, for your FxPlug plug-in to render.

Overview

One of the biggest changes between FxPlug 3 and 4 is that now there is no FxPlug API access at render time. Rendering occurs out-of-process, reducing the amount of back and forth between the host app and the plug-in, which is essential for performance. Thus, if you call [FxParameterRetrievalAPI_v6](/documentation/professional_video_applications/fxparameterretrievalapi_v6) at render time, it will return *nil*.

This means that your plug-in must prepare what it needs to know to render before render time. Then, at render time, this information is provided to your plug-in. This information is called the *Plug-in State*. It’s represented by a byte-buffer of [NSData](/documentation/Foundation/NSData) of your own creation that can be passed to the rendering method at render time. The content of the `NSData` object is up to you, but it typically contains parameter values from the host application’s UI, or values calculated from those parameter values.