Google Auth Library for Ruby

Tim Emiola
Copyright © 2015 Google, Inc.
Apache 2.0

Gem Version Build Status Coverage Status Dependency Status


This is Google's officially supported ruby client library for using OAuth 2.0 authorization and authentication with Google APIs.


This library is in Alpha. We will make an effort to support the library, but we reserve the right to make incompatible changes when necessary.


Be sure is in your gem sources.

For normal client usage, this is sufficient:

$ gem install googleauth

Example Usage

require 'googleauth'

# Get the environment configured authorization
scopes =  ['',
authorization = Google::Auth.get_application_default(scopes)

# Add the the access token obtained using the authorization to a hash, e.g
# headers.
some_headers = {}

Application Default Credentials

This library provides an implementation of application default credentials for Ruby.

The Application Default Credentials provide a simple way to get authorization credentials for use in calling Google APIs.

They are best suited for cases when the call needs to have the same identity and authorization level for the application independent of the user. This is the recommended approach to authorize calls to Cloud APIs, particularly when you're building an application that uses Google Compute Engine.

User Credentials

The library also provides support for requesting and storing user credentials (3-Legged OAuth2.) Two implementations are currently available, a generic authorizer useful for command line apps or custom integrations as well as a web variant tailored toward Rack-based applications.

The authorizers are intended for authorization use cases. For sign-on, see Google Identity Platform

Example (Web)

require 'googleauth'
require 'googleauth/web_user_authorizer'
require 'googleauth/stores/redis_token_store'
require 'redis'

client_id = Google::Auth::ClientId.from_file('/path/to/client_secrets.json')
scope = ['']
token_store =
authorizer =
  client_id, scope, token_store, '/oauth2callback')

get('/authorize') do
  # NOTE: Assumes the user is already authenticated to the app
  user_id = request.session['user_id']
  credentials = authorizer.get_credentials(user_id, request)
  if credentials.nil?
    redirect authorizer.get_authorization_url(login_hint: user_id, request: request)
  # Credentials are valid, can call APIs
  # ...

get('/oauth2callback') do
  target_url = Google::Auth::WebUserAuthorizer.handle_auth_callback_deferred(
  redirect target_url

Example (Command Line)

require 'googleauth'
require 'googleauth/stores/file_token_store'

OOB_URI = 'urn:ietf:wg:oauth:2.0:oob'

scope = ''
client_id = Google::Auth::ClientId.from_file('/path/to/client_secrets.json')
token_store =
  :file => '/path/to/tokens.yaml')
authorizer =, scope, token_store)

credentials = authorizer.get_credentials(user_id)
if credentials.nil?
  url = authorizer.get_authorization_url(base_url: OOB_URI )
  puts "Open #{url} in your browser and enter the resulting code:"
  code = gets
  credentials = authorizer.get_and_store_credentials_from_code(
    user_id: user_id, code: code, base_url: OOB_URI)

# OK to use credentials


Authorizers require a storage instance to manage long term persistence of access and refresh tokens. Two storage implementations are included:

  • Google::Auth::Stores::FileTokenStore
  • Google::Auth::Stores::RedisTokenStore

Custom storage implementations can also be used. See token_store.rb for additional details.

What about auth in google-apis-ruby-client?

The goal is for all auth done by google-apis-ruby-client to be performed by this library. I.e, eventually google-apis-ruby-client will just take a dependency on this library. This update is a work in progress, but should be completed by Q2 2015.


This library is licensed under Apache 2.0. Full license text is available in COPYING.




Please report bugs at the project on Github. Don't hesitate to ask questions about the client or APIs on StackOverflow.