How Can I Configure Google OAuth for Self-Hosted n8n on Umbrel?

Below is a detailed explanation and some workarounds for your situation:

Why the Issue Occurs

Google requires the Authorized domains field to contain publicly accessible, valid domain names. When your n8n instance uses a local domain like umbrel.local (or a local IP address), Google rejects these values because they aren't routable on the public internet.

Possible Workarounds

1. Use a Tunneling Service (e.g. ngrok)

For testing purposes you can expose your local instance using a tunneling service like ngrok. This creates a temporary public URL that you can add as an authorized domain. For example:

• Run ngrok to forward your local port (often 5678):

  BASHCopied
  ngrok http 5678

• Update your Google OAuth credentials with the public URL given by ngrok.
• Use that URL in both the OAuth Redirect URI and as the authorized domain in your consent screen.

2. Set up a Custom Domain with a Valid SSL Certificate

If you plan to go into production or need a more permanent solution, register a custom domain and point it to your server’s public IP or create a DNS entry that resolves properly. Make sure to:

• Use a DNS provider to manage your domain.
• Obtain and configure an SSL certificate (Let’s Encrypt is a popular free option).
• Update both your n8n instance URL and Google OAuth credentials accordingly.

Security note:
Using a custom domain with valid SSL improves security. Just make sure that your server is hardened correctly before exposing it publicly. The use of HTTPS will ensure the OAuth flow remains secure.

Summary

Since Google doesn’t accept local domains or IP addresses in the OAuth consent screen setup, you have to either temporarily expose your instance with a public URL (via ngrok) or permanently assign a custom domain with proper DNS/SSL configuration. Both approaches will allow you to add an acceptable domain in the Authorized domains field and complete your n8n Google OAuth setup.

This guidance is based on the n8n documentation for configuring Google OAuth and the authenticated setup steps provided.