There are 2 repositories under security-key topic.
🔏 A small WebAuthn API wrapper that translates to/from pure JSON using base64url.
A helper for OpenSSH to interact with FIDO2 and U2F security keys through native Windows Hello API
An Open-Source FIDO U2F implementation on nRF52 SoC
Django Authentication Backend For Passkeys
This is for setting up a Yubico Passwordless Ubuntu Login or Logins
TurtlPass Firmware for Raspberry Pi Pico (RP2040)
Background program to skip Bluetooth smartphone choice in Windows Hello passkey prompts
A smartcard keyboard firmware, based on Nitrokey Pro
My list of congrats and call-outs for services supporting (or not) security keys
Agama Project to authenticate people using USB FIDO2 security keys
GnuPG wrapper script for symmetric encryption with YubiKey (challenge-response). Includes an adapter for QtPass and Browserpass (passwordstore).