Context

Users may encounter issues when attempting to log in to LangSmith using Single Sign-On (SSO), such as the SSO button not working, receiving authentication errors, or being redirected back to the login page.

Answer

If you're experiencing issues logging into LangSmith via SSO, follow these troubleshooting steps:

1. Clear your browser cache and cookies

   • This is often necessary when switching between authentication methods or after SSO is newly configured

   • Try using an incognito/private browser window to test if the issue persists

2. Check corporate firewall and security tools

   • If users are not being redirected to your SSO provider, corporate firewalls or security tools (like Zscaler) may be blocking the requests

   • Work with your IT team to allowlist these domains:

     • smith.langchain.com

     • api.smith.langchain.com

   • Look for 403 errors in browser developer tools or HAR files that may indicate blocked requests

3. Verify SSO permissions and group membership

   • Ensure you are a member of the correct SSO group in your organization's identity provider (e.g., Okta, Azure AD)

   • If you're using Azure AD, verify that the application has the necessary permissions configured

4. Check SSO configuration

   • Confirm the redirect URL is correctly set to: [langsmith-domain]/api/v1/oauth/custom-oidc/callback

   • Verify that the client ID in your LangSmith deployment matches the one in your identity provider

   • Ensure all required permissions are granted in your identity provider

5. Access through identity provider dashboard

   • Try accessing LangSmith directly through your organization's SSO dashboard (e.g., Okta dashboard)

   • You may need to verify your email address the first time you log in

If you continue to experience issues, contact your IT team to verify the SSO application configuration is correct and all necessary permissions are in place.