---
id: webauthn
version: "3.0.0"
license: BSD-3-Clause
license_treatment: permissive
maintenance: active
---

# webauthn — Pythonic WebAuthn

License: permissive · Maintenance: active · Downloads: 7.0M/mo

## What it is and what it does

py_webauthn is a server-side implementation of the WebAuthn specification that handles the cryptographic validation of passwordless authentication credentials. It works with any FIDO2-compliant authenticator—security keys, Touch ID, Face ID, Windows Hello, Android biometrics—and exposes four core methods: generate_registration_options, verify_registration_response, generate_authentication_options, and verify_authentication_response. The library assumes JSON transport between server and browser, with base64url encoding for binary data to avoid extra dependencies.

The package depends on pyasn1, pyasn1-modules, cbor2, cryptography, and pyOpenSSL to handle the underlying cryptographic operations and ASN.1 parsing required by the WebAuthn spec. It provides helper dataclasses for type-safe construction of inputs and outputs, and utility functions for JSON serialization and base64url conversion. Developers integrate it by generating challenge-based options on the server, sending them to the browser's WebAuthn API, then validating the returned credential against the server-stored challenge.

Use it for:

- Add passwordless login to a web application using hardware security keys or platform biometrics.
- Implement multi-factor authentication where WebAuthn serves as a second factor alongside passwords.
- Build a registration flow that enrolls users' authenticators and stores their public keys server-side.
- Verify authentication responses from browser-based WebAuthn ceremonies without managing passwords.
- Support cross-platform authentication across desktop, mobile, and web clients with a single server implementation.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Implements server-side WebAuthn validation for passwordless authentication using FIDO2-compliant authenticators like security keys, biometrics, and platform authenticators.

Yes. This is a production-stable, actively maintained library with no known vulnerabilities, low install friction, and a permissive license. Install it if you need to add WebAuthn support to a Python backend and are targeting Python 3.10+. The API is straightforward and the dependency footprint is small and well-established.

## Install

pip install webauthn
uv add webauthn
poetry add webauthn

## Installing webauthn

Before you install: Low install friction with a pure-Python wheel and five stable runtime dependencies. Active maintenance with a recent release and no known vulnerabilities.

License in practice: BSD-3-Clause permissive license allows commercial and private use with minimal restrictions.

Quickstart:

pip install webauthn

from webauthn import generate_registration_options, verify_registration_response

options = generate_registration_options(rp_id="example.com", rp_name="Example")
# Send options to client, receive response, then:
verified = verify_registration_response(credential=response, expected_challenge=challenge)

Requires Python 3.10 or later.

Verify before relying:

- Whether the library's type hints and dataclass helpers fully cover all WebAuthn spec edge cases in production deployments.
- Performance characteristics when handling high-volume concurrent registration and authentication flows.

## Package facts

- License: BSD-3-Clause (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 7.0M/month (top 5,000 on PyPI)
- Known vulnerabilities: none known

## Tags

webauthn server implementation, fido2 authentication, passwordless login, security key verification, biometric authentication server, authentication, cryptography, fido2

[View on SkillFed](https://skillfed.io/packages/webauthn) · [View on PyPI](https://pypi.org/project/webauthn/)