About authentication with SAML SSO
SAML single sign-on (SSO) gives organization owners and enterprise owners on GitHub a way to control and secure access to organization resources like repositories, issues, and pull requests. Organization owners can invite your user account on GitHub to join their organization that uses SAML SSO, which allows you to contribute to the organization and retain your existing identity and contributions on GitHub.
When you access resources within an organization that uses SAML SSO, GitHub will redirect you to the organization's SAML IdP to authenticate. After you successfully authenticate with your account on the IdP, the IdP redirects you back to GitHub, where you can access the organization's resources.
Note: Outside collaborators aren't required to authenticate with an IdP to access the resources in an organization with SAML SSO. For more information on outside collaborators, see "Permission levels for an organization."
If you have recently authenticated with your organization's SAML IdP in your browser, you are automatically authorized when you access a GitHub organization that uses SAML SSO. If you haven't recently authenticated with your organization's SAML IdP in your browser, you must authenticate at the SAML IdP before you can access the organization.
You must periodically authenticate with your SAML IdP to authenticate and gain access to the organization's resources on GitHub.com. The duration of this login period is specified by your IdP and is generally 24 hours. This periodic login requirement limits the length of access and requires you to re-identify yourself to continue. You can view and manage your active SAML sessions in your security settings. For more information, see "Viewing and managing your active SAML sessions."
To use the API or Git on the command line to access protected content in an organization that uses SAML SSO, you will need to use an authorized personal access token over HTTPS or an authorized SSH key.
If you don't have a personal access token or an SSH key, you can create a personal access token for the command line or generate a new SSH key. For more information, see "Creating a personal access token" or "Generating a new SSH key and adding it to the ssh-agent."
To use a new or existing personal access token or SSH key with an organization that uses or enforces SAML SSO, you will need to authorize the token or authorize the SSH key for use with a SAML SSO organization. For more information, see "Authorizing a personal access token for use with SAML single sign-on" or "Authorizing an SSH key for use with SAML single sign-on."
About OAuth Apps and SAML SSO
You must have an active SAML session each time you authorize an OAuth App to access an organization that uses or enforces SAML SSO.
After an enterprise or organization owner enables or enforces SAML SSO for an organization, you must reauthorize any OAuth App that you previously authorized to access the organization. To see the OAuth Apps you've authorized or reauthorize an OAuth App, visit your OAuth Apps page.