Check country availability
Pre-purchase check, so you can warn BEFORE a customer invests in KYC (regulated review is async, 1-3 days). Tells you whether we have deliverable inventory, and what address the customer needs:
addressConstraint: geo→ the registered address MUST be in one of the returnedareas(the only place we have stock). A different-area address passes pre-approval but the number can never be assigned.addressConstraint: country→ any in-country address works.addressConstraint: none→ field-only / instant country, no address. Call this before starting the KYC form for regulated countries.
API key authentication - use your Zernio API key as a Bearer token
In: header
Query Parameters
ISO-2 country code.
Response Body
application/json
application/json
import Zernio from '@zernio/node';const zernio = new Zernio({ apiKey: process.env.ZERNIO_API_KEY });const { data } = await zernio.phonenumbers.checkPhoneNumberAvailability({ query: { country: 'string', },});console.log(data);{
"country": "string",
"numberType": "string",
"available": true,
"addressConstraint": "geo",
"areas": [
"string"
]
}{
"error": "Unauthorized"
}Cancel a port-in DELETE
Cancel an in-flight port (wrong number, staying with the old carrier). Only orders that haven't ported can be cancelled; a completed port is a normal number release instead. The carrier may report `cancel-pending` briefly while the losing carrier acknowledges; it settles to `cancelled`.
Check portability POST
Pre-flight portability check: whether each number can be ported in and whether it qualifies for FastPort, BEFORE the user commits to a port order (LOA, invoice, service address). Read-only; creates no order and bills nothing.