> ## Documentation Index
> Fetch the complete documentation index at: https://docs.turnkey.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Email and SMS OTP authentication
> Set up and implement email and SMS OTP authentication using the Turnkey Swift SDK.
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## Overview
This guide shows how to implement email or SMS OTP authentication using the Turnkey Swift SDK and the Auth Proxy.\
You'll send an OTP to a user's contact, present a verification screen, and complete the flow with a single call that handles login or signup.
Before you begin:
* Ensure you've completed the setup in [Getting Started](/solutions/embedded-wallets/integration-guide/swift/getting-started) and enabled the Auth Proxy with Email/SMS OTP in the Turnkey Dashboard.
* Make sure your app is configured with `TurnkeyConfig` and `TurnkeyContext.configure(...)`.
## Send an OTP code
Create or update your login screen to collect the user's email. When the user submits the form, call `initOtp(contact:otpType:)` with the email and `.email`.
This sends a one-time code to the provided address.
On success, keep the returned `otpId` along with the email so you can navigate to your OTP screen. In the next section, you'll verify the code the user enters.
```swift LoginView.swift focus={2,5-6,11,25-27} theme={"system"}
import SwiftUI
import TurnkeySwift
struct LoginView: View {
@EnvironmentObject var turnkey: TurnkeyContext
@State private var email = ""
@State private var errorMessage: String?
var body: some View {
VStack(spacing: 12) {
TextField("you@example.com", text: $email)
.keyboardType(.emailAddress)
.textInputAutocapitalization(.never)
.autocorrectionDisabled()
.frame(height: 48)
.overlay(RoundedRectangle(cornerRadius: 8).stroke(.gray.opacity(0.3)))
Button("Continue with email") {
Task {
guard email.contains("@") else {
errorMessage = "Please enter a valid email"
return
}
do {
let result = try await turnkey.initOtp(contact: email, otpType: .email)
// Navigate to your OTP screen with `email` and `result.otpId`
// Example: OtpScreen(email: email, otpId: result.otpId)
} catch {
errorMessage = "Failed to initialize OTP"
}
}
}
.disabled(!email.contains("@"))
}
.padding()
.alert("Error", isPresented: .constant(errorMessage != nil)) {
Button("OK") { errorMessage = nil }
} message: {
Text(errorMessage ?? "")
}
}
}
```
## Verify the OTP code
On your OTP screen, call `completeOtp(...)` with the user-entered code.\
This will verify the code and automatically complete login or signup as needed.
```swift OtpScreen.swift focus={2,5,8-9,11,16,33-38} theme={"system"}
import SwiftUI
import TurnkeySwift
struct OtpScreen: View {
@EnvironmentObject var turnkey: TurnkeyContext
@Environment(\.dismiss) private var dismiss
let email: String
let otpId: String
@State private var code = ""
@State private var errorMessage: String?
var body: some View {
VStack(spacing: 12) {
TextField("Enter 6-digit code", text: $code)
.keyboardType(.numberPad)
.textContentType(.oneTimeCode)
.multilineTextAlignment(.center)
.frame(height: 48)
.overlay(RoundedRectangle(cornerRadius: 8).stroke(.gray.opacity(0.3)))
.onChange(of: code) { newValue in
code = String(newValue.prefix(6))
}
Button("Verify") {
Task {
guard code.count == 6 else {
errorMessage = "Please enter a 6-digit code"
return
}
do {
_ = try await turnkey.completeOtp(
otpId: otpId,
otpCode: code,
contact: email,
otpType: .email
)
// Navigate to your main app upon success
dismiss()
} catch {
errorMessage = "Invalid code. Please try again."
}
}
}
.disabled(code.count != 6)
}
.padding()
.alert("Error", isPresented: .constant(errorMessage != nil)) {
Button("OK") { errorMessage = nil }
} message: {
Text(errorMessage ?? "")
}
}
}
```
### SMS OTP
For SMS, pass an E.164-formatted phone number and use `otpType: .sms`:
```swift theme={"system"}
let result = try await turnkey.initOtp(contact: "+15551234567", otpType: .sms)
// Navigate to your OTP screen with `contact` (phone) and `result.otpId`
```
Tip: You can use a library like [PhoneNumberKit](https://github.com/PhoneNumberKit/PhoneNumberKit) to normalize user input to E.164.
### Notes
* Default OTP length is 6; if you've customized the OTP length in the dashboard, validate accordingly (up to 9 digits).
* To resend a code, call `initOtp(contact:otpType:)` again with the same contact.
***
## Next steps