Add SSO docs

fern/products/docs/pages/authentication/sso.mdx

@@ -1,7 +1,61 @@
 ---
 title: Single Sign-On
+subtitle: Enterprise authentication for secure access to your Fern dashboard
 ---
 
-Fern supports SSO so that your docs site is gated for your team and customers.
+Fern's Single Sign-On (SSO) is an enterprise feature that enables your organization to authenticate users through your existing identity provider, providing secure access to your Fern dashboard at `dashboard.buildwithfern.com`.
 
-<Warning>Docs are coming soon for this page.<br/><br/>Please [book a demo](https://buildwithfern.com/book-demo) or [reach out to us](https://buildwithfern.com/book-demo) to get set up with this feature. </Warning> 
+## What SSO unlocks
+
+When SSO is enabled for your organization, authenticated users gain access to:
+
+- **User and Organization Management**: Manage team members and organizational settings
+- **Analytics Dashboard**: View detailed web analytics and Ask Fern metrics
+- **Billing and Subscription Management**: Monitor your plan usage, view invoices, and manage your subscription tier
+
+## How it works
+
+Fern's SSO integration allows your team to use their existing corporate credentials to access the Fern platform. Instead of managing separate Fern accounts, users authenticate through your organization's identity provider and are automatically granted appropriate access to your Fern resources.
+
+### Authentication flow
+
+1. User navigates to [dashboard.buildwithfern.com](https://dashboard.buildwithfern.com)
+2. User selects SSO login and enters their organization domain
+3. User is redirected to your organization's identity provider
+4. After successful authentication, user is redirected back to Fern with appropriate permissions
+5. User gains access to dashboard features based on their role
+
+## Supported identity providers
+
+Fern supports SSO integration with any identity provider that implements industry-standard protocols:
+
+- **SAML 2.0**: Compatible with providers like Okta, OneLogin, Azure AD, and others
+- **OIDC (OpenID Connect)**: Works with Google Workspace, Auth0, and other OIDC-compliant providers
+
+## Getting started
+
+<Note>
+SSO is available as part of the Enterprise plan.
+</Note>
+
+To set up SSO for your organization:
+
+1. **Contact Fern Support**: Reach out via Slack or [contact our team](https://buildwithfern.com/contact) to begin the SSO setup process
+
+2. **Provide IdP Information**: Share details about your identity provider configuration, including:
+   - IdP type (SAML or OIDC)
+   - Metadata URL or certificate information
+   - Attribute mappings for user identification
+
+3. **Configure Your IdP**: Add Fern as a service provider in your identity provider with the connection details we provide
+
+4. **Test the Integration**: Work with our team to test the SSO flow and ensure users can successfully authenticate
+
+5. **Go Live**: Once testing is complete, enable SSO for your organization
+
+## Automatic user provisioning
+
+When a user successfully authenticates through SSO:
+- Their account is automatically created in Fern if it doesn't exist
+- User information is synced from your identity provider
+- Appropriate permissions are assigned based on their role