Added basic docs on SSO/OIDC

README.md

@@ -326,6 +326,8 @@ Enable users to sign in with external identity providers like Google, Azure AD,
 https://your-domain.com/api/auth/sso/callback/{provider-id}
 ```
 
+Need help? The [SSO & OIDC guide](docs/SSO-OIDC-SETUP.md) now includes a working Authentik walkthrough plus troubleshooting tips. If you upgraded from a version earlier than v3.8.10 and see `TypeError … url.startsWith` after the callback, delete the old provider and add it again using the Discover button (see [#73](https://github.com/RayLabsHQ/gitea-mirror/issues/73) and [#122](https://github.com/RayLabsHQ/gitea-mirror/issues/122)).
+
 ### 3. Header Authentication (Reverse Proxy)
 Perfect for automatic authentication when using reverse proxies like Authentik, Authelia, or Traefik Forward Auth.
 

docs/SSO-OIDC-SETUP.md

@@ -81,6 +81,26 @@ Replace `{provider-id}` with your chosen Provider ID.
    - Client Secret: [Your Okta Client Secret]
    - Click "Discover" to auto-fill endpoints
 
+### Example: Authentik SSO Setup
+
+Working Authentik deployments (see [#134](https://github.com/RayLabsHQ/gitea-mirror/issues/134)) follow these steps:
+
+1. In Authentik, create a new **Application** and OIDC **Provider** (implicit flow works well for testing).
+2. Start creating an SSO provider inside Gitea Mirror so you can copy the redirect URL shown (`https://your-domain.com/api/auth/sso/callback/authentik` if you pick `authentik` as your Provider ID).
+3. Paste that redirect URL into the Authentik Provider configuration and finish creating the provider.
+4. Copy the Authentik issuer URL, client ID, and client secret.
+5. Back in Gitea Mirror:
+   - Issuer URL: the exact value from Authentik (keep any trailing slash Authentik shows).
+   - Provider ID: match the one you used in step 2.
+   - Click **Discover** so Gitea Mirror stores the authorization, token, and JWKS endpoints (Authentik publishes them via discovery).
+   - Domain: enter the email domain you expect to match (e.g. `example.com`).
+6. Save the provider and test the login flow.
+
+Notes:
+- Make sure `BETTER_AUTH_URL` and (if you serve the UI from multiple origins) `BETTER_AUTH_TRUSTED_ORIGINS` point at the public URL users reach. A mismatch can surface as 500 errors after redirect.
+- Authentik must report the user’s email as verified (default behavior) so Gitea Mirror can auto-link accounts.
+- If you created an Authentik provider before v3.8.10 you should delete it and re-add it after upgrading; older versions saved incomplete endpoint data which leads to the `url.startsWith` error explained in the Troubleshooting section.
+
 ## Setting up OIDC Provider
 
 The OIDC Provider feature allows other applications to use Gitea Mirror as their authentication provider.
@@ -165,6 +185,7 @@ When an application requests authentication:
 1. **"Invalid origin" error**: Check that your Gitea Mirror URL matches the configured redirect URI
 2. **"Provider not found" error**: Ensure the provider is properly configured and enabled
 3. **Redirect loop**: Verify the redirect URI in both Gitea Mirror and the SSO provider match exactly
+4. **`TypeError: undefined is not an object (evaluating 'url.startsWith')`**: This indicates the stored provider configuration is missing OIDC endpoints. Delete the provider from Gitea Mirror and re-register it using the **Discover** button so authorization/token URLs are saved (see [#73](https://github.com/RayLabsHQ/gitea-mirror/issues/73) and [#122](https://github.com/RayLabsHQ/gitea-mirror/issues/122) for examples).
 
 ### OIDC Provider Issues
 

scripts/setup-authentik-test.sh

@@ -114,10 +114,10 @@ EOF
         echo "======================================"
         echo "1. Access Authentik at http://localhost:9000"
         echo "2. Login with akadmin / admin-password"
-        echo "3. Create OAuth2 Provider for Gitea Mirror:"
+        echo "3. Create an Authentik OIDC Provider for Gitea Mirror:"
         echo "   - Name: gitea-mirror"
-        echo "   - Redirect URIs:"
-        echo "     http://localhost:4321/api/auth/callback/sso-provider"
+        echo "   - Redirect URI:"
+        echo "     http://localhost:4321/api/auth/sso/callback/authentik"
         echo "   - Scopes: openid, profile, email"
         echo ""
         echo "4. Create Application:"
@@ -131,10 +131,14 @@ EOF
         echo "6. Configure SSO in Gitea Mirror:"
         echo "   - Go to Settings → Authentication & SSO"
         echo "   - Add provider with:"
+        echo "     - Provider ID: authentik"
         echo "     - Issuer URL: http://localhost:9000/application/o/gitea-mirror/"
+        echo "     - Click Discover to pull Authentik endpoints"
         echo "     - Client ID: (from Authentik provider)"
         echo "     - Client Secret: (from Authentik provider)"
         echo ""
+        echo "If you previously registered this provider on a version earlier than v3.8.10, delete it and re-add it after upgrading to avoid missing endpoint data."
+        echo ""
         ;;
         
     stop)