Question

After getting auth token with required permissions, I am trying to access user’s tasks.

Request URL:

https://www.googleapis.com/tasks/v1/lists/%40default/tasks?key={YOUR_API_KEY}

Code to Make request:

    public void FetchTasks(string url)
    {
        var httpWebRequest = HttpWebRequest.CreateHttp(url);
        httpWebRequest.BeginGetResponse(new AsyncCallback(FinishedWebRequest), httpWebRequest);
    }

    private void FinishedWebRequest(IAsyncResult ar)
    {
        var httpWebRequest = ar.AsyncState as HttpWebRequest;
        var httpWebResponse = (HttpWebResponse) httpWebRequest.EndGetResponse(ar);
        byte[] responseByteArray= new byte[200];
        httpWebResponse.GetResponseStream().Read(responseByteArray, 0, responseByteArray.Length);
    }

Response

    {
 "error": {
  "errors": [
   {
    "domain": "global",
    "reason": "required",
    "message": "Login Required",
    "locationType": "header",
    "location": "Authorization"
   }
  ],
  "code": 401,
  "message": "Login Required"
 }
}

Do I need anything else as part of request headers along with auth token in the URL?

Answer 1

You need to set the Authorization HTTP header to a valid access_token for the user whose tasks you’d like to access. Assuming you’ve completed the OAuth 2.0 dance and have a valid access_token, you can set the header by changing FetchTasks() to something like this:

public void FetchTasks(string url, string accessToken)
{
    var httpWebRequest = HttpWebRequest.CreateHttp(url);
    request.Headers.Add("Authorization", "Bearer "+accessToken);
    httpWebRequest.BeginGetResponse(new AsyncCallback(FinishedWebRequest), httpWebRequest);
}

Also, it looks like you’re accessing the APIs using HTTP directly. Managing OAuth 2.0 tokens can be a bit cumbersome, You may want to investigate using the official Google .NET API client library which takes care of a lot of the heavy lifting for you.