# GitLab API
Find API Clients for GitLab [on our website](https://about.gitlab.com/applications/#api-clients).
You can use [GitLab as an OAuth2 client](oauth2.md) to make API calls.
## Authentication with OAuth2 token
### OAuth2 token (as a parameter)
### OAuth2 token (as a header)
Read more about [GitLab as an OAuth2 client](oauth2.md).
# GitLab Integration
GitLab integrates with multiple third-party services to allow external issue trackers and external authentication.
- [LDAP](ldap.md) Set up sign in via LDAP
- [OmniAuth](omniauth.md) Sign in via Twitter, GitHub, GitLab, and Google via OAuth.
- [SAML](saml.md) Configure GitLab as a SAML 2.0 Service Provider
- [CAS](cas.md) Configure GitLab to sign in using CAS
- [Slack](slack.md) Integrate with the Slack chat service
- [OAuth2 provider](oauth_provider.md) OAuth2 application creation
- [Gmail actions buttons](gmail_action_buttons_for_gitlab.md) Adds GitLab actions to messages
GitLab Enterprise Edition contains [advanced JIRA support](http://doc.gitlab.com/ee/integration/jira.html) and [advanced Jenkins support](http://doc.gitlab.com/ee/integration/jenkins.html).
Integration with services such as Campfire, Flowdock, Gemnasium, HipChat, Pivotal Tracker, and Slack are available in the form of a Project Service.
You can find these within GitLab in the Services page under Project Settings if you are at least a master on the project.
Project Services are a bit like plugins in that they allow a lot of freedom in adding functionality to GitLab, for example there is also a service that can send an email every time someone pushes new commits.
# Google OAuth2 OmniAuth Provider
To enable the Google OAuth2 OmniAuth provider you must register your application with Google. Google will generate a client ID and secret key for you to use.
1. Sign in to the [Google Developers Console](https://console.developers.google.com/) with the Google account you want to use to register GitLab.
1. Provide the project information
- Project name: 'GitLab' works just fine here.
- Application type: "Web Application"
- Authorized JavaScript origins: This isn't really used by GitLab but go ahead and put 'https://gitlab.example.com' here.
- Authorized redirect URI: 'https://gitlab.example.com/users/auth/google_oauth2/callback'
1. Under the heading "Client ID for web application" you should see a Client ID and Client secret (see screenshot). Keep this page open as you continue configuration. 
1. On your GitLab server, open the configuration file.
```sh
sudo editor /etc/gitlab/gitlab.rb
- [API](api/README.md) Automate GitLab via a simple and powerful API.
- [GitLab as OAuth2 authentication service provider](integration/oauth_provider.md). It allows you to login to other applications from GitLab.
- [GitLab Basics](gitlab-basics/README.md) Find step by step how to start working on your commandline and on GitLab.
- [Importing to GitLab](workflow/importing/README.md).
- [Markdown](markdown/markdown.md) GitLab's advanced formatting system.
- [Migrating from SVN](migration/README.md) Convert a SVN repository to Git and GitLab
- [Permissions](permissions/permissions.md) Learn what each role in a project (guest/reporter/developer/master/owner) can do.
- [SSH](ssh/README.md) Setup your ssh keys and deploy keys for secure access to your projects.
- [Web hooks](web_hooks/web_hooks.md) Let GitLab notify you when new code has been pushed to your project.
- [Workflow](workflow/README.md) Using GitLab functionality and importing projects from GitHub and SVN.
- [Quick Start](ci/quick_start/README.md)
- [Configuring project (.gitlab-ci.yml)](ci/yaml/README.md)
- [Test Clojure applications](ci/examples/test-clojure-application.md)
- Help your favorite programming language and GitLab by sending a merge request with a guide for that language.
# Twitter OAuth2 OmniAuth Provider
1. Fill in the application details.
- Name: This can be anything. Consider something like "\<Organization\>'s GitLab" or "\<Your Name\>'s GitLab" or
- Description: Create a description.
- Website: The URL to your GitLab installation. 'https://gitlab.example.com'
- Callback URL: 'https://gitlab.example.com/users/auth/twitter/callback'
- Agree to the "Developer Agreement".
1. On your GitLab server, open the configuration file.
```sh
sudo editor /etc/gitlab/gitlab.rb
```sh
cd /home/git/gitlab
# Facebook OAuth2 OmniAuth Provider
1. Enter a name for your app. This can be anything. Consider something like "<Organization>'s GitLab" or "<Your Name>'s GitLab" or
1. Enter the address of your GitLab installation at the bottom of the package
1. On your GitLab server, open the configuration file.
```sh
sudo editor /etc/gitlab/gitlab.rb
sudo -u git -H editor config/gitlab.yml
```ruby
gitlab_rails['omniauth_providers'] = [
On the sign in page there should now be a Facebook icon below the regular sign in form. Click the icon to begin the authentication process. Facebook will ask the user to sign in and authorize the GitLab application. If everything goes well the user will be returned to GitLab and will be signed in.
# Need this if under RELATIVE_URL_ROOT
unless Gitlab.config.gitlab.relative_url_root.empty?
# If website is mounted using relative_url_root need to remove it first
@env['PATH_INFO'] = @request.path.sub(Gitlab.config.gitlab.relative_url_root,'')
lfs_response = Gitlab::Lfs::Router.new(project, @user, @request).try_call
case git_cmd
when *Gitlab::GitAccess::DOWNLOAD_COMMANDS
if !Gitlab.config.gitlab_shell.upload_pack
false
elsif user
Gitlab::GitAccess.new(user, project).download_access_check.allowed?
end
when *Gitlab::GitAccess::PUSH_COMMANDS
if !Gitlab.config.gitlab_shell.receive_pack
false