A
Acme
docs.acme.dev
Your Acme code is 482 619
Branded SMS Your docs Your console
VERIFY API
OTP verification API for fast, fraud-safe one-time codes
Send a one-time code by SMS, voice or WhatsApp with one request and check it with another. Resell the verification API under your logo while MCM AI spots risky sign-ups before any code goes out.
- SMS, voice and WhatsApp
- Automatic fallback
- White-label
Verify a user
+1 415 ••• 0199
One-time code
482619
Delivery route
SMSready
Voiceready
WhatsAppstandby
Requesting a code…
Status
PENDING
risk: low01Why teams build on it
A phone verification API built to deliver and protect
Send a one-time passcode, check it, and let MCM AI keep fake sign-ups out. Smart fallback gets every code to the user, and two API calls cover the whole flow.
Verification overview live
01
Codes that land
Smart channel fallback gets every code to the user.
02
Fewer fake sign ups
MCM AI flags risky requests before a code is sent.
03
Two calls total
Send a code, check a code, and you are done.
02Send and check
Send and check OTP codes in two API calls
One request sends a code, and one request checks it. The API handles code creation, expiry and retries, so developers add secure sign in and checkout steps in an afternoon.
- Simple send and check
- Auto expiry and retries
- Custom code length
Channel
Code length
1Send a code
Request
POST /2026-01/verify{ "to": "+14155550199", "channel": "sms","length": 6 }
Response
→ 202 { "id": "ver_4c1e", "status": "pending" }expires automatically · retries handled
Auto expiry and retries are handled for you
2Check the code
Request
POST /2026-01/verify/ver_4c1e/check{ "code": "482619" }
Response
→ 200 { "status": "approved" }
482619
approved03Channel fallback
SMS, voice and WhatsApp OTP with automatic fallback
Codes go out by SMS, voice call or WhatsApp. If a message does not arrive, the API tries the next channel automatically so your customers’ users never get stuck.
SMSready
Your verification code is 482 619
if not
delivered
delivered
Voice callready
Ready to call
next
channel
channel
WhatsAppstandby
482 619
Copy code
Localized messagesSame code, in your users’ language.
EN
Your verification code is 482 619
ES
Su código de verificación es 482 619
FR
Votre code de vérification est 482 619
DE
Ihr Bestätigungscode lautet 482 619
04MCM AI fraud guard
Fraud prevention for sign-ups and OTP traffic
MCM AI checks each request for signs of fake accounts and code pumping, then blocks or slows suspicious traffic. Your customers save money and keep sign ups clean.
- Risk scoring per request
- Blocks code pumping
- Fraud insights dashboard
7
risk score
Send code- Trusted device
- Normal request rate
- Real-looking number
05One verification, end to end
How the verification flow works, step by step
- 01
Subscriber
Signs up on a shopping app and asks for a login code.
- 02
MCM AI
Scores the request, sees a trusted device and approves sending.
- 03
Network
Delivers the code by SMS and falls back to voice if needed.
- 04
MCM AI
Blocks a burst of suspicious requests from the same source.
06White-label
White-label OTP verification under your logo
Messages, docs and the console all carry your logo, while MCM AI protects every request behind the scenes. One API, as many branded experiences as you have customers.
MCM Verify API
one API · many brands
N
Nova
docs.nova.io
Your Nova code is 482 619
Branded SMS Your docs Your console
P
Pulse
docs.pulse.app
Your Pulse code is 482 619
Branded SMS Your docs Your console
07Use cases
OTP verification use cases: sign-up, login, checkout and recovery
One verification API covers every moment you need to confirm a real person on a real phone.
Sign-up verification
Confirm a real phone number when a user creates an account, so fake and duplicate sign-ups stay out.
- SMS, voice or WhatsApp
- Fraud scoring
Login and two-factor codes
Send a one-time passcode at login and check it with a second request for simple, secure two-factor sign-in.
- Send and check
- Custom code length
Checkout confirmation
Add a quick code step before a purchase or payment so only the real customer completes checkout.
- Auto expiry
- Auto retries
Password reset and recovery
Let users prove it is them by phone before they reset a password or recover an account.
- Automatic fallback
- Localized messages
Testimonials
What clients say after 90 days.
Real teams, real numbers — from sales floors, CX desks, and support queues.
+24%
First Contact Resolution
11 hrs
Per week returned to sales
−38%
Average Handle Time
FAQ
OTP verification API FAQs
What is an OTP verification API?expand_more
An OTP verification API lets your app confirm a user's phone number with a one-time code. With MCM Verify and OTP you make one request to send the code and one request to check it. The API creates, stores, expires and retries codes for you.
Which channels can send one-time passcodes?expand_more
Verify and OTP sends codes by SMS, voice call or WhatsApp, with automatic fallback between them. Messages can be localized for your users.
How does automatic OTP fallback work?expand_more
If a code does not arrive on the first channel, the API tries the next channel automatically, for example SMS first and then a voice call. Your customers' users do not get stuck waiting for a code.
How do I prevent fake sign ups and OTP code pumping?expand_more
MCM AI scores every verification request and blocks or slows suspicious traffic before a code is sent. That stops fake accounts and code pumping, saves your customers money and keeps sign ups clean.
Do developers need to generate or store OTP codes?expand_more
No. The API creates, stores, expires and checks codes for you. Developers only send a request to start verification and another to check the code, and can set a custom code length.
Can I resell the verification API under my own brand?expand_more
Yes. Verify and OTP is white-label, so messages, docs and the console all carry your logo while MCM AI protects every request behind the scenes.
What is OTP code pumping?expand_more
Code pumping is when bots trigger large volumes of one-time codes to run up message costs. MCM AI scores every request and blocks or slows suspicious traffic before a code is sent, so your customers do not pay for fake traffic.
What can I use an OTP verification API for?expand_more
Common uses are sign-up verification, login and two-factor codes, checkout confirmation, and password reset or account recovery. One API sends the code and one request checks it.
Ready to launch OTP verification?
Talk to our partner team and launch SMS, voice and WhatsApp one-time codes under your own brand.
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