I am trying to gain access to my BigQuery enabled Google API project using the .net Google APIs.
Using a console application, I am trying to authenicate first by supplying my simple API key in the URI, then just trying to get the list of projects.
The error I am receiving when I call Fetch() on the project list is: Login Required [401]
var bigqueryService = new BigqueryService{ Key = "MY-API_KEY" };
var projectList = bigqueryService.Projects.List().Fetch();
I am purposefully not using OAuth2 as we don't need any user data.
The API key simply identifies your app to the API console for quota purposes and other housekeeping. It's not authoritative for accessing BigQuery, as we do consider the BigQuery data as "user data."
If you're just trying to get an OAuth 2 access token for playing around quickly, you can use the OAuth 2 playground: https://code.google.com/oauthplayground/
This token will be valid for one hour and can be copied/pasted as the access_token query parameter
Here's the scope for BigQuery to use in the playground:
https://www.googleapis.com/auth/bigquery
In the end, you'll either want to use the native client (out of band) flow: https://developers.google.com/accounts/docs/OAuth2InstalledApp
Or the server-to-server (service accounts) flow: https://developers.google.com/accounts/docs/OAuth2ServiceAccount
I don't have quick samples handy for those in .NET, but post another question on SO if you can't find them-- I'm sure someone will chip in!