n8n 3.0 needs Docker to self-host: a public URL for Sume webhooks

n8n 3.0 requires a Docker-based deployment for self-hosting and no longer supports installs run with npm or npx n8n (n8n 3.0 breaking changes, read 2026-10-02). For Sume, the move changes nothing about the rule that a webhook URL must be public HTTPS, but a container makes it easier to publish the wrong port or address.

The vendor change

What Sume requires of the callback

Both job webhooks and run webhooks require a public HTTPS URL. Localhost, private-network and non-HTTPS URLs are rejected with 400 invalid_request. The run-webhook docs add that the URL is checked again at delivery time and that redirects are not followed, so a 3xx is not a delivery.

Checklist for a container

• Set the n8n webhook base URL to the public HTTPS address of your reverse proxy, not the container's internal address, so the $execution.resumeUrl you hand to Sume is reachable from outside.
• Terminate TLS in front of the container with a certificate Sume can validate.
• Do not put a redirect (for example HTTP to HTTPS, or a trailing-slash redirect) between Sume and the webhook path.
• Respond with a 2xx after storing the event. Sume times each attempt out at 10 seconds.

Verify, then test

Use the dashboard's Send test (or POST /v1/webhooks/test-deliveries) to push a dummy signed webhook.test event to your URL before spending anything on a real job. It never replays a real job, so it costs nothing. Then verify the x-sume-webhook-signature against the raw body.

Sume cannot reach an n8n instance on a private network. If that is your setup, poll status_url from n8n instead; polling needs only outbound access.