oauth - can I use grant_type=client_credentials for google api?

Question

I create a clientid, and clientcredentials in google console. when I request the token with grant_type=client_credentials. I got 401 unauthrorized.

{
  "error": "invalid_client",
  "error_description": "Unauthorized",
  "error_uri": ""
}

Answer 1

The error means that you are not authenticated. Also client_credentials is not a valid value for grant_type that I am aware of.

The only ones I know of are

• authorization_code
• refresh_token

It looks like grant_type=client_credentials is part of the RFC for Oauth2 but its not something I have seen implemented in Googles Authentication servers.

Anwser: No to my knowledge you cant use grant_type=client_credentials with Google APis.

update: just got word back from Google. I was correct they do not support this grant_type.