fido2
FIDO2/WebAuthn library for implementing clients and servers.
Decision gist · record as of 2026-08-14
Yes. Active maintenance, low install friction, no known vulnerabilities, and production-stable status make this suitable for production use. The multi-license composition requires license review, but is clearly disclosed. Install if you need FIDO2/WebAuthn support; the platform-specific setup (especially Linux Udev rules) is a one-time operational concern, not a blocker.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.10 or later.
- On Windows 10+, USB device access requires Administrator privileges or use of WindowsClient.
- On Linux, requires Udev rules or root access for HID device communication.
License · maintenance · safety
(unclear) — Multi-licensed: primarily BSD 2-clause, with Apache 2.0 code in fido2/hid/ and Mozilla Public License 2.0 for bundled public suffix list. Verify compatibility with your project's license policy before use.
last release 2026-06-29 (46 days) · last repo commit 2026-06-29 · 543 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 2,589,350 downloads/mo, #2,981 on PyPI
Alternatives
Verify before relying
pip install fido2
from fido2.client import ClientData
from fido2.server import Fido2Server
server = Fido2Server(rp_id='example.com')- Whether the library supports the latest FIDO2 specification versions beyond what the description states.
- Performance characteristics when handling multiple concurrent authenticator connections.
- Specific error handling and recovery behavior for device disconnection or communication failures.
What it is and what it does
fido2 is a Python library for implementing FIDO2 and WebAuthn authentication flows. It provides low-level device communication with USB authenticators via the CTAP 1 and 2 protocols, as well as higher-level client and server classes for building passwordless authentication systems. The library handles cryptographic verification of attestation and assertion signatures, making it suitable for both authenticator clients and relying party (server) implementations.
The package depends only on cryptography and is actively maintained by Yubico. It supports Windows, macOS, and Linux, though platform-specific setup is required—particularly on Linux where Udev rules must be configured for HID device access. Optional NFC support is available via the pyscard library when installed with the [pcsc] extra.
Use it for
- Build a WebAuthn-compliant authentication server that accepts FIDO2 devices like YubiKeys for passwordless login.
- Implement a desktop or CLI application that communicates directly with USB authenticators for cryptographic operations.
- Verify FIDO2 attestation signatures to ensure authenticators are genuine during registration flows.
- Add second-factor authentication support to an existing application using standard FIDO2 devices.
- Develop cross-platform security tools that interact with hardware security keys.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes.
Active maintenance, low install friction, no known vulnerabilities, and production-stable status make this suitable for production use. The multi-license composition requires license review, but is clearly disclosed. Install if you need FIDO2/WebAuthn support; the platform-specific setup (especially Linux Udev rules) is a one-time operational concern, not a blocker.
Install
fido2 on PyPI
Before you install
Low install friction with a single runtime dependency (cryptography). Active maintenance with a recent release 46 days ago and ongoing repository activity. Requires Python 3.10 or later.
Requires Python 3.10 or later. On Windows 10+, USB device access requires Administrator privileges or use of WindowsClient. On Linux, requires Udev rules or root access for HID device communication.
License in practice
Multi-licensed: primarily BSD 2-clause, with Apache 2.0 code in fido2/hid/ and Mozilla Public License 2.0 for bundled public suffix list. Verify compatibility with your project's license policy before use.
Quickstart
pip install fido2
from fido2.client import ClientData
from fido2.server import Fido2Server
server = Fido2Server(rp_id='example.com')Verify before relying
- Whether the library supports the latest FIDO2 specification versions beyond what the description states.
- Performance characteristics when handling multiple concurrent authenticator connections.
- Specific error handling and recovery behavior for device disconnection or communication failures.
Package facts
| License | Not declared unclear |
| Python support | Supports the current Python release <4,>=3.10 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 1 packagecryptography |
| Maintenance | Actively maintained 46 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 2,589,350 / month, #2,981 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableIntended Audience :: DevelopersIntended Audience :: System AdministratorsLicense :: OSI Approved :: Apache Software LicenseLicense :: OSI Approved :: BSD LicenseLicense :: OSI Approved :: Mozilla Public License 2.0 (MPL 2.0)Operating System :: MacOSOperating System :: Microsoft :: WindowsOperating System :: POSIX :: LinuxTopic :: InternetTopic :: Security :: CryptographyTopic :: Software Development :: Libraries :: Python Modules |
Evidence: fido2-2.2.1-py3-none-any.whl
Tags
Let your AI agent find packages like this
Example. Real query, live index.
You found this page by searching. An agent finds it by wishing: SkillFed indexes 14,416 PyPI packages by what they can do, searchable in plain language.
wish › “fido2 webauthn library”
- fido2Implements FIDO2 and WebAuthn protocols for communicating with USB…
- webauthnImplements server-side WebAuthn validation for passwordless…
- django-otp-webauthnAdds WebAuthn Passkey support to Django OTP, enabling passwordless…
Give your agent the search over MCP, or paste the wish link into any chat.
More Python Modules packages
Converts domain names between Unicode and ASCII-compatible encoding (Punycode) according to IDNA 2008 and Unicode Technical Standard 46, with security validation and broader script coverage than the standard library.
Install it if you work with internationalized domain names, need to validate domains, or use HTTP clients that depend on it transitively.
Setuptools is a Python build backend and package management tool that handles building, distributing, and installing Python packages, including support for C/C++ extension modules.
PyYAML parses and emits YAML 1.1 data format, enabling serialization and deserialization of configuration files and Python objects to and from human-readable YAML text.
Pydantic validates Python data structures against type hints, coercing and checking input at runtime to ensure it matches a declared schema.
Provides reusable metadata objects for use with PEP-593 `typing.Annotated` to express common constraints like bounds, collection sizes, and predicates on types.
Install it if you use or build libraries that need to express type constraints in a standardized, inspectable way—or if you want to annotate your own types with…
Provides runtime tools to inspect and introspect Python type annotations, enabling programmatic examination of type hints at execution time.
See also pyu2f · soft-webauthn · webauthn · yubico-client · django-otp-webauthn · PyOTP · hidapi · oauthenticator · stytch · hid