Application Default Credentials not available - localhost project

Question

I'm trying to make a call to Google Speech API using the library method (I don't want to make a direct call to an endpoint) and I get this error:

The Application Default Credentials are not available.
They are available if running in Google Compute Engine.
Otherwise, the environment variable GOOGLE_APPLICATION_CREDENTIALS
must be defined pointing to a file defining the credentials.

I have already downloaded the JSON credentials file from my service account and defined the GOOGLE_APPLICATION_CREDENTIALS environment variable pointing to it.

I have also created this GCLOUD_PROJECT variable which is set to the "project_id" field in my JSON file.

I am not providing any extra authentication when using the library method - but this has worked in another local environment which probably had some other configuration that I am missing.

 var speech = SpeechClient.Create();
            var response = speech.Recognize(new RecognitionConfig()
            {
                Encoding = RecognitionConfig.Types.AudioEncoding.Linear16,

                LanguageCode = languageCode,
            }, RecognitionAudio.FromFile(file));

The authentication file is of type service account, if that helps.

"type": "service_account",

Answer 1

Setting the environment variable worked for me. Use the code:

System.Environment.SetEnvironmentVariable("GOOGLE_APPLICATION_CREDENTIALS", <<path>>);

You need to use path of json file that you get from Google Api page.