Duo Auth API

Paid#13 of 25 in Multi-Factor Authentication APIs

Duo Auth API: A server-side API for enrolling users and verifying Duo push, phone, and passcode authentication. Ranked #13 of 25 in Multi-Factor Authentication APIs by our editors (7.7/10); pricing: Pricing on request; best for teams integrating Duo push and passcode authentication.

7.7/10★★★★☆Editor score

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Duo Auth API7.7 Visit Duo

At a glance

• Editor score
  7.7 / 10
• Pricing
  Pricing on request
• Best for
  Teams integrating Duo push and passcode authentication
• Founded
  2010
• Facts checked
  24 Sep 2026

• Where it wins

  • Supports enrollment, status checks, and pre-authentication policy checks
  • Can initiate and verify authentication transactions
  • Offers Duo Push, phone callbacks, SMS passcodes, and passcodes

• Where it doesn't

  • Requires a Duo account and API credentials
  • Pricing is contact-sales and tied to Duo service plans
  • No email OTP or webhook support

Our verdict on Duo Auth API

Duo Auth API is a cloud REST interface for developers integrating two-factor authentication into custom applications and services. It covers user enrollment, enrollment-status checks, pre-authentication policy checks, and the initiation and verification of authentication transactions. Supported methods include Duo Push, phone callbacks, SMS passcodes, and passcodes. Its fit is clearest for teams building server-side integrations around those factors, rather than buyers seeking a broad collection of authentication channels.

The API's workflow spans more than the authentication prompt: applications can enroll users and check status before starting an authentication transaction, then verify its result. Documentation lists SDK languages including Python, Java, PHP, C#, Perl, Ruby, and Go. That gives teams working in those languages a documented route into the API, while the product remains a developer-facing integration rather than a standalone end-user application. Duo account access and API credentials are required.

According to the vendor's pricing information, there is no standalone API price; commercial access is tied to Duo service plans, and pricing is contact-sales. Buyers should therefore evaluate it as part of the wider Duo service rather than assume an independently priced API. Duo Auth API suits small, mid-market, and enterprise teams whose requirements center on its documented enrollment and push or passcode flows. Teams requiring email OTP or webhook support should look for an alternative that explicitly provides those capabilities.

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Duo Auth API pricing

Duo Auth API fact sheet

Alternatives to Duo Auth API

• AuthgearA flexible MFA API for web, mobile, hosted, and self-managed deployments.8.9
• DescopeA broad MFA and CIAM toolkit with adaptive access, provisioning, and passwordless flows.8.8
• FusionAuthA flexible MFA and identity platform with free self-hosting and paid cloud tiers.8.7

See all Duo Auth API alternatives →

Featured on iTechGuides

Duo Auth API is listed in our Multi-Factor Authentication APIs directory. Add the badge to your site — it links back to this page.

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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

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Last updated 7 Oct 2026 · How we research and update