How to call Google API from .NET/C# Web Application

Question

I am struggling to call APIs hosted in Google Cloud https://apis-explorer.appspot.com/apis-explorer/?base=https%3A%2F%2Finnovative-glass.appspot.com%2F_ah%2Fapi#p/mirror/v1/

Up to my understanding, APIs are exposed as REST service. I need to make rest service call from .net application.

I have done OAuth Authentication. I am passing access_token as per the guidance given https://developers.google.com/accounts/docs/OAuth2WebServer

My Code:

UriBuilder uriBuilder = new UriBuilder("https://innovative-glass.appspot.com/_ah/api/mirror/v1/timeline");
string userId = Session["userId"] as string;
var state = Utils.GetStoredCredentials(userId);
NameValueCollection queryParameters = HttpUtility.ParseQueryString(uriBuilder.Query);
queryParameters.Set("access_token", state.AccessToken);
uriBuilder.Query = queryParameters.ToString();

var request = (HttpWebRequest)WebRequest.Create(uriBuilder.ToString());
request.Method = "GET";
var response = (HttpWebResponse)request.GetResponse();

I am getting UnAuthorized exception. Is my understanding is right? Am I doing right way?

I (like many here) don’t know the details of the .NET library. If you could have a peek at the HTTP going back and forth, there are a lot of people who might be able to spot a problem. — Tim Bray
– Tim Bray, Commented Oct 20, 2013 at 4:30

Scarygami · Accepted Answer · 2013-10-21 13:45:51Z

1

It seems that cloud endpoints don't use the Google API default of accepting access_token as query parameter. According to the Discovery document the equivalent query parameter is oauth_token so it should work with:

queryParameters.Set("oauth_token", state.AccessToken);

Alternatively (which in my opinion is the better solution) you can also set the Authorization header of the request instead of adding the token as query parameter:

request.Headers.Add("Authorization", "Bearer " + state.AccessToken);

answered Oct 21, 2013 at 13:45

Scarygami

15.6k2 gold badges37 silver badges24 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Prisoner · Accepted Answer · 2013-10-21 13:26:14Z

0

Where are you getting the AccessToken from, and are you sure it is still a valid token? Remember that access tokens expire about an hour after being generated, although can be revoked earlier.

Clicking on the sign-in button at innovative-glass.appspot.com gives me an origin mismatch error, so it looks like you may also have a configuration issue.

Have you been able to get it to work using just the API Explorer?

answered Oct 21, 2013 at 13:26

Prisoner

50.9k7 gold badges59 silver badges113 bronze badges

Collectives™ on Stack Overflow

How to call Google API from .NET/C# Web Application

2 Answers 2

Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Related