Verify your customer's phone numbers for free
Power your 2FA flow with Contiguity. We only bill you for sending the text, not for the OTP API – unlike $0.05+ at Twilio and others. Or, have users text a code to you – completely for free.
No credit card required
OTP powers verification for the world's best
from hobbyists to Fortune 500 companies
No Number Leasing
Send OTPs without leasing a phone number. Contiguity handles everything automatically.
No Custom Logic
No need to store OTP sessions or build custom verification logic. We handle it all for you.
Great Delivery
Enterprise-level delivery rates with automatic retries and carrier optimization built-in.
33 Languages
OTP messages automatically localized in 33 languages for a better user experience.
Free OTP API included
Every Contiguity customer gets a fully managed OTP API at no extra cost. Send codes, verify them, handle sessions – we do it all. Uses your existing quota or unlimited plan, unlike competitors charging $0.05+ per verification.
Two API calls, that's it. Send an OTP and get an ID. Verify with the code. No sessions to manage, no state to track.
import { Contiguity } from "contiguity"const contiguity = new Contiguity("contiguity_sk_...your_token...")// Send OTPconst otp = await contiguity.otp.send({to: "+1234567890"})// Verify OTPawait contiguity.otp.verify({otp_id: otp.id,code: "123456"})
Professional messages in 33 languages. Your users get clean, localized OTP messages automatically – no configuration needed.
Customers message you
We also support reverse OTP, where customers message you to prove they own their number. Save on costs and improve verification rates, without adding significant friction to your flows.
Cost Savings
Contiguity doesn't bill you for receiving ROTPs, and you don't have to lease a number to receive them. It's the cheapest way to verify a phone number.
Better Delivery
Since users message you, delivery is much higher – especially internationally, where sending to the US is almost always included.
More Secure
Receiving SMS is cheap, while sending SMS is expensive. Stop most fraudsters using fake phone numbers in their tracks