Alert URL rules
2026-05-01 · Billing
HTTPS, port 443, a public address, no redirects, and a small JSON body.
The alert URL is checked when you save it and again before every send. It must be HTTPS on 443. It must resolve to public addresses. Private networks are rejected so the feature cannot be pointed at an internal service.
Redirects are not followed. The response body is ignored. Only the status code matters: 2xx is success. Other codes retry after 10 seconds and again after 60.
The payload is at most 8 KB. You may set up to 10 headers, printable ASCII, and not the hop-by-hop names.
A test call uses the same rules. A test that fails is a preview of a real alert that would fail. Fix the URL before you depend on it.
Ready to call it? Start with the quickstart, the API guide, or pricing.