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Documentation Index

Fetch the complete documentation index at: https://stytch.com/docs/llms.txt

Use this file to discover all available pages before exploring further.

One-time passcodes (OTP) let you verify users by sending a short code over SMS or WhatsApp. OTPs are a good fit for passwordless login, phone verification, and step-up authentication when you need an additional factor.
OTPs can be targeted by toll fraud. Review the Toll fraud resources before enabling SMS at scale.

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How OTPs work

  1. Collect the user’s phone number and request a passcode.
  2. The user enters the code they receive.
  3. Your app verifies the code and optionally establishes a session.

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Next steps

API integration

Send and authenticate OTPs from your backend.

SDK integration

Add OTPs to Stytch Login with the frontend SDK.