VOICE-OTP
When the text is late, we call.
If a passcode does not arrive within your timeout, the same verification continues as a carrier voice call that reads the code aloud in your user's language.
A safety net for sign-ups
Voice is not a separate product. It catches what SMS misses
Calls that get picked up
Localized caller ID over direct SIP interconnects.
Ringing almost at once
The call starts the moment the SMS timeout expires.
Spoken in their language
Clear, natural speech with a replay on keypress.
How fallback works
SMS goes out
A priority SMS is sent with a timeout you choose, for example 30 seconds.
Timeout passes
No delivery receipt inside the window, so the session moves to voice.
We place the call
A direct SIP call reads the passcode with a local caller ID.
Verification closes
The user enters the code or presses 1 to hear it again. One webhook reports the result.
Route specificationView full specification
- Answer-seizure ratio
- 94.6 %
- Post-dial delay p95
- 2.1 s
- Concurrent calls
- 5,000
- TTS languages
- 28
- CDR retention
- 13 months
- Audio encoding
- G.711a, G.711u, Opus
- Interfaces
- REST, SIP trunk
- DTMF
- RFC 2833, in-band
Never lose a sign-up to a late text.
Console
API
curl -X POST "$BASE_URL/spam/checks" \
-H "Authorization: Bearer $API_KEY" \
-H "Content-Type: application/json" \
-d '{"items": [{"kind": "sender",
"value": "+15555550123"}]}'Submit a checkDocs
Request a route test