Nick
Honestly I have not tried AoG with the library yet. If you set up the [Conversation Components](http://github.com/actions-on-google/conversation-components-nodejs) sample, you may be able to run it, ask for media, and see...
Did you ever see if this works?
What language/locale is it configured as? Do you see any other logs relating to device registration?
I believe that the supported list of languages lines up closely with the [Actions on Google](https://developers.google.com/actions/localization/languages-locales) list of locales. Dutch currently is not one of them. There's no public timeline...
It seems like Assistant now supports [th-TH and nl-NL](https://developers.google.com/actions/localization/languages-locales).
This [reference page](https://developers.google.com/assistant/sdk/reference/rpc/languages) shows all of the supported languages right now.
I can't speak to future releases or times.
If you don't want to use the mic, you can use the `textinput.py` sample.
Check `textinput.py` for how to use text input.
You may need to take a look at both [textinput](https://github.com/googlesamples/assistant-sdk-python/blob/master/google-assistant-sdk/googlesamples/assistant/grpc/textinput.py) for getting the input, and [pushtotalk](https://github.com/googlesamples/assistant-sdk-python/blob/master/google-assistant-sdk/googlesamples/assistant/grpc/pushtotalk.py) for processing the output audio response that you get.