How to create Github OAuth credentials and access tokens with Meteor, without logging-in the user nor using accounts-github

meteor-github-oauth.js

if (Meteor.isClient) {
  Template.hello.events({
    'click .github': function() {
      // initiate the OAuth process: 
        // ask for the desired permissions
        // run the callback after the user authorizes the app
      // https://github.com/meteor/meteor/blob/devel/packages/github/github_client.js#L8
      Github.requestCredential({
        loginStyle: 'popup',
        requestPermissions: ['gist']
      }, function(tokenOrError) {
        if (tokenOrError && tokenOrError instanceof Error) {
          // Throw a Meteor error
          console.log('error getting the token');
          return;
        }

        // retrieves credentialSecret from localStorage
        // https://github.com/meteor/meteor/blob/devel/packages/oauth/oauth_client.js#L152
        var credentialSecret = OAuth._retrieveCredentialSecret(tokenOrError);
        console.log('credentialToken:', tokenOrError, 'credentialSecret:', credentialSecret);

        var accessToken = Meteor.promise('getGithubAccessToken', tokenOrError, credentialSecret);
      });
    }
  });
}

if (Meteor.isServer) {
  Meteor.startup(function () {
    // sets up the github client service on your server
    ServiceConfiguration.configurations.upsert(
      { service: "github" },
      { $set: { clientId: "<YOUR-CLIENT-ID-HERE>", secret: "<YOUR-CLIENT-SECRET-HERE>" } }
    );
  });

  Meteor.methods({
    getGithubAccessToken: function(credentialToken, credentialSecret) {
      // Github.retrieveCredential wraps OAuth.retrieveCredential, which wraps OAuth._retrievePendingCredential
      // From the Meteor docs here: https://github.com/meteor/meteor/blob/devel/packages/oauth/pending_credentials.js#L72
        // When an oauth request is made, Meteor receives oauth credentials
        // in one browser tab, and temporarily persists them while that
        // tab is closed, then retrieves them in the browser tab that
        // initiated the credential request.
        //
        // _pendingCredentials is the storage mechanism used to share the
        // credential between the 2 tabs
      // After retrieval, they are deleted from the db (unless stored in the User Collection by the developer or by an accounts package)
      var credentials = Github.retrieveCredential(credentialToken, credentialSecret);
      console.log('accessToken:', credentials.serviceData.accessToken);
      return credentials.serviceData.accessToken;
    }
  });
}