Check portability

Pre-flight portability check: whether each number can be ported in, whether it qualifies for FastPort, and its current carrier and line type where the carrier lookup knows them, BEFORE the user commits to a port order (LOA, invoice, service address). Read-only; creates no order and bills nothing.

Works without an API key for one number per request. Keyless calls are what the checker at https://zernio.com/port-your-number makes: they must come from that page (a browser bot check rejects scripted callers with 401), are limited per IP (3 a minute, 10 a day) and by a shared daily budget (429 once spent), because each check runs a paid carrier lookup. Each portable keyless result carries a claimId and a claimUrl: a signup link that opens the dashboard's port form with the number filled in. Send an API key to check up to 50 numbers without those limits.