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Verify Users in Seconds

Send one-time passwords via SMS or email with a single API call. Codes generate, deliver, and validate through one endpoint.

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User verification

Authenticate users without building OTP infrastructure

Phone number and email verification require code generation, secure storage, expiration handling, and rate limiting. Conjoin Verifications handles all of this through a single API.

Capabilities

Everything you need for user verification

SMS verification

Send OTP codes to mobile phones worldwide. Codes deliver through priority routing that bypasses standard message queues, reaching recipients within seconds.

Email verification

Deliver verification codes to email addresses with high inbox placement. Branded templates match your application design while Conjoin handles delivery infrastructure.

Configurable expiration

Set code expiration from 1 minute to 24 hours based on your security requirements. Expired codes reject automatically without additional validation logic.

Rate limiting

Built-in rate limiting prevents abuse without manual configuration. Limits apply per phone number and email address, blocking brute force attempts automatically.

Secure code generation

Cryptographically random codes generate server-side with configurable length from 4 to 8 digits. No code storage required in your application.

Resend handling

Users can request new codes when previous ones expire or fail to arrive. Resend requests invalidate previous codes and generate fresh ones with reset expiration timers.

Global delivery

Verify users across 200+ countries with automatic carrier selection for SMS and optimized email routing. Delivery rates and latency remain consistent worldwide.

Delivery confirmation

Track verification code delivery status in real time. Know whether codes reached recipients before users report issues, reducing support burden.

< 5s
Median delivery

Time from API call to code receipt

99.2%
Verification rate

Users who complete verification

Global
Coverage

Reach recipients worldwide

Why it matters

Confirm user identity without the complexity

Verify users without building OTP infrastructure

Building verification flows requires generating cryptographically secure codes, storing them with expiration tracking, implementing rate limiting, and handling edge cases like resends. Conjoin Verifications provides all of this through two API calls: send and verify.
In practice

Call the send endpoint with a phone number or email. Conjoin generates the code, delivers it, and stores it securely. When the user submits the code, call the verify endpoint. The response confirms whether the code is valid, expired, or incorrect.

Reduce account takeover with phone verification

Password-only authentication leaves accounts vulnerable to credential stuffing and phishing. Adding phone verification as a second factor confirms that account access requires possession of a physical device.
In practice

A user logs in from a new device. Your application triggers a verification request. The user receives an SMS code within seconds, enters it, and gains access. An attacker with stolen credentials cannot proceed without the phone.

Confirm email ownership before account creation

Unverified email addresses lead to bounced messages, spam complaints, and wasted resources on fake accounts. Email verification during signup confirms ownership before storing the address.
In practice

A new user enters their email during registration. Your application sends a verification code through Conjoin. The user enters the code from their inbox, and you proceed with account creation knowing the email address is valid and accessible.

Handle verification edge cases automatically

Users request codes that never arrive, enter codes after expiration, or attempt verification from multiple devices. Conjoin handles these cases with built-in expiration, rate limiting, and resend logic.
In practice

A user requests a code but does not receive it. They tap resend after 30 seconds. The previous code invalidates, a new one generates, and the expiration timer resets. Your application receives consistent responses without tracking code state.

Built for Your Workflow

Ship faster with solutions designed for real-world needs

Challenge

Signup abandonment from slow verification

How Conjoin solves this

Send verification codes through priority routing that bypasses standard message queues. Codes reach recipients within seconds, keeping users engaged in the signup flow before they navigate away.

Impact

Reduce signup abandonment with fast code delivery that keeps users in the flow.

Challenge

Building OTP validation logic from scratch

How Conjoin solves this

Call the verify endpoint with the code the user entered. Conjoin checks expiration, attempt limits, and code correctness, returning a clear status: approved, expired, invalid, or max attempts exceeded.

Impact

Validate OTP codes without implementing expiration tracking or brute-force protection.

Challenge

Email verification delays account activation

How Conjoin solves this

Send email verification codes through pre-warmed IPs with high inbox placement. Users enter codes directly instead of clicking links, which avoids spam filter issues and provides a faster verification experience.

Impact

Verify email ownership faster with code entry instead of link clicks.

Challenge

Rate limiting verification requests manually

How Conjoin solves this

Conjoin applies rate limits per phone number and email address automatically. Excessive requests block with retry-after headers, preventing abuse without manual configuration or database tracking.

Impact

Prevent verification abuse without building rate limiting infrastructure.

Ship your application today

Start building with Conjoin today. Free tier includes everything you need to prototype and launch. Scale when you're ready.

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