Check port-in eligibility
Run a synchronous pre-flight portability check on a single number before creating a port-in request — no LOA is required and no order is created. US/CA numbers are checked live against Telnyx; numbers elsewhere resolve to DIDWW, which has no synchronous check and returns a check-not-supported status. Surface the verdict in the porting wizard to catch a non-portable number up front instead of waiting out the 2–7 business-day submission window. Requires the numbers:read scope.
Authorizations
Dashboard JWT token from Clerk
Headers
Stripe-style idempotency token. Pass a stable, client-generated value (1-255 chars) to dedupe retries on transient timeouts. The same key+credential+path replays the original response for 24h on 2xx (5min on 4xx, 30s on 5xx). Returns 409 if a concurrent request with the same key is already in flight; replayed responses include the Idempotency-Replay: true response header.
1 - 255Sandbox opt-in for Clerk-session-authenticated requests. Set to true to route the call through the test-mode pipeline: no real provider delivery, no credits deducted, response meta.test_mode: true. Ignored for live API keys (dv_live_sk_*) — server-to-server clients must use a test-prefixed key (dv_test_sk_*) to exercise sandbox. Test-prefixed keys unconditionally enable sandbox regardless of this header.
true, false Body
The number to pre-check, plus the optional losing carrier for context.