Hi, I released (a few days ago) MixerApi v1.1.0 which includes a new JWT Auth plugin (GitHub - mixerapi/jwt-auth: A JWT authentication plugin for CakePHP [read-only]). This supports both HMAC and RSA with JWKS.
You might find this useful if you are starting a new API project in CakePHP. It can be installed with MixerAPI is a whole or as a stand alone plugin.