Connecticut issues no roofing-specific licence. Roofing on an existing home falls under the Home Improvement Contractor registration, so the number to ask a Connecticut roofer for begins with HIC — there is no separate roofing credential to look up, and a contractor offering one is describing something the state does not issue.
Try a free lookup — no signup, right here on this page. For programmatic access, take a free API key — 250 requests a month, no card. Also on RapidAPI and, if you would rather not write code at all, the Apify Store.
What is verifiable: the roofer's HIC registration, which is checkable here and which Connecticut law requires for home improvement work.
Full coverage detail, including the caveats that apply to every Connecticut lookup, is on the Connecticut page.
The API is on RapidAPI with a free tier: Contractor License Verification. It is also on the Apify Store: Contractor License Lookup & Verification. Full schema at /docs.