NKS...sending to host

I’m trying to support NKS in my plugin and I’ve got most of it working, but I’m having a hard time figuring out how to query the host with a “hostCanDo” call, and then how to actually send note data to the host for the light guides.

Has anyone out there successfully implemented this?

There was a host callback method added, but only for VST2 I believe:

Yep. The VST3 counterpart is more complicated so it’s been shelved temporarily while we attend to some more urgent work.

For anyone else who’s trying to implement NKS, here’s some code that I used to send and receive from an NKS host (Maschine or Komplete Kontrol). It’s not 100% complete because of the NDA, but this should hopefully save someone some time.

class MyProcessor  : public AudioProcessor,
	                   public VSTCallbackHandler // <- need this for callback

    std::function<VstHostCallbackType> hostCallback = nullptr;

    // etc...

// need this just for the audioMasterCanDo definition used below...
namespace Vst2
#include <juce_audio_processors/format_types/VST3_SDK/pluginterfaces/vst2.x/aeffect.h>
#include <juce_audio_processors/format_types/VST3_SDK/pluginterfaces/vst2.x/aeffectx.h>

// host -> plugin
pointer_sized_int MyProcessor:: handleVstPluginCanDo (int32 opcode,
									                  pointer_sized_int lArg2,
									                  void* ptrArg,
									                  float opt)
	auto text = (const char*) ptrArg;
	if(strcmp(text, nks::vse::effect_can_nks_string()) == 0)
		return 1;

	return 0;

void MyProcessor::handleVstHostCallbackAvailable(std::function&lt;VstHostCallbackType&gt;&amp;&amp; callback)
    hostCallback = callback;

int32 MyProcessor::canHostDo(char* text)
	if (hostCallback != nullptr)
		return (hostCallback(Vst2::audioMasterCanDo, 0, 0, text, 0) != 0);
	return 0;

pointer_sized_int MyProcessor::hostVendorSpecific(int32 lArg1, int32 lArg2, void* ptrArg, float floatArg)
	if (hostCallback != nullptr)
		return hostCallback(Vst2::audioMasterVendorSpecific, lArg1, lArg2, ptrArg, floatArg);
	return 0;

Hi, I know it has been two years but right now i am trying to do the same thing. I downloaded the sdk and switched to developer mode.I handled the artwork, presets, knob mapping but i couldn’t manage to complete the code section. Did you add anything else ? Would this be enough to complete this section and have an NKS compatible plugin ?

The sdk is ok.
We have it working well with juce5.
But currently it is subject to terms so I’d suggest you contact NI directly. If you have specific juce questions feel free to contact me privately.

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@pizzafilms, @ttg-2

Thank you for your answers.
I contacted them. They send me a link to access their sdk and a document to go through.
I started with installing the Maschine CP. I created my presets.i use an independent preset system. It allows user to save and load presets in a certain file extension. But of course it is an xml file. Then i set the mapping order.i tested it with a komplete keyboard. I had some issues but now everything works. It took me a while to fix the issues. Now i have my presets ready, i created necessary artworks according to that document. I think the last step is to adding tbe header and necessary codes to my project. This is the point that i need help. I see there is two demos. One for windows and one for mac. I compiled them by using cmake but i cannot debug it. The both examples are not like juce template. So i am confused. I don’t know what to add my code. And after this secrion, is there anything else? After this should i send them the files for approval?

You first need to test it and see if all NKS features you’ve decided to use are working as expected. You can debug your code seeing if nks supported host such as MASCHINE or KOMPLETE KONTROL properly handles your plugin or instrument.

I am testing it in MASCHINE. For now looks like it works fine. I am able to load presets, switch to another, control the knobs. I can do all these, once i plugin my komplete keyboard to my computer. I only couldn’t handle the code side.

After adding the “VendorSpecificExtension.h” to my processor and the code above, is it going to be completed? I don’t know what to do on the header and code side.

I am able to debug my plugin but i cannot debug the one that is provided in the demo folder of NKS VST SDK. So i don’t know which methods or parameters are coming from the NKS header. I read their NKS VST Developer SDK document page.But i couldn’t understand what to do the complete it.

I need help to go through the correct procedure to complete the process. Is there a cleaner manual or a post or an example that i can review?

Don’t know anything about NKS, but to me it seems that you generally don’t have any experience in adding third party libraries to C++/JUCE projects, am I right?

If this is the case, I guess you should learn such general things first as I guess this is some basic programing knowledge that is expected by the developers and not very specific to NKS. Maybe playing around with some random open source lib to link to a demo plugin as a pure learning task and discussing that here on the forums to learn the general ideas before starting with a closed source lib that no one can really talk about in public due to NDA restrictions could be a better first step in that direction…? Correct me if I’m wrong and all those stuff like linking to external libs in general is something you are familiar with

I feel like you’re confused with a lot of things altogether.

  1. What are you trying to achieve from NKS?
    If you only want to use NKS then you don’t have to do much. just put debug points and see they’re being called. even with the code above.

  2. It feels you need some understanding of the VST2 architecture (as a reminder - you need license for it in addition to NKS. which cannot be obtained for a while now).
    You can try supporting ‘open’ VST2 extensions such as PreSonus ones and see if it is working for you. after you get the hang of VST2 extensions the NKS would be a breeze.

@PluginPenguin , @ttg-2 adding an external lib is ok. I see what you mean. I was trying to see if there is a better and more detailed explanation for the steps. I mean;

  1. nks needs to get your preset list. XXX is the method that will get them. Insert your preset list as a xml document array to it.

As you mentioned it is hard to find anything about NKS since it is restricted by an NDA.I will try to contact them directly and see if they can guide me to finalize it. Thank you very much for your valuable answers.

Has anyone successfully updated to NKS version 2.0?
Everything works smoothly with VST2 and NKS v1.5.
I have some doubts with integrating NKS VST3 Interfaces into JUCE-based plugin, also can’t get VST3 host context without modify JUCE modules.

You have to modify JUCE modules, unfortunately. The host starts querying for NKS support before the AudioProcessor (and thus VST3ClientExtensions) is initialized. More on that here.

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@t0m @reuk Native Instruments NKS is a pretty popular technology, I believe that JUCE should support the latest NKS-VST3 SDK. Can you rise the priority on a smooth implementation for it?


I believe that my response here still stands:

This feature has been requested in the past, but only infrequently, so it’s not clear that it would be an impactful change for the majority of our users. The change itself would also require some investigation, and potentially substantial reworking of the VST3 wrapper, which would be time-consuming. At the moment, the cost/benefit ratio doesn’t seem particularly compelling.

You could open a feature request to allow for earlier querying of the client extensions and/or NKS support (it’s not clear to me whether early querying of client extensions is sufficient to support NKS). If the feature request is popular, that would indicate that this work is valuable to our users.

Also, please note that we’ve already decided on the features we want to include in JUCE 8. Until v8 is released, we need to focus on those features (along with bugfixes/maintenance), so we won’t be able to start on other new features until after JUCE 8 is released.

I just asked the NI NKS folks about this issue at ADC. It’s been brought to their attention quite recently. Chances are they’ll be fixing it from their side.


The NKS team released a hotfix for Komplete Kontrol that fixes the initialization problem they have been having in the context of JUCE plugins simply by querying the NKS interface extensions a bit later. A similar fix for Maschine is expected before 2024.


I love these smaller down to earth companies for that… there is no way in hell Apple would do such a fix, even if their asses are on fire.