#PKCE

The Vue browser application of a civil-service personnel system: a self-service portal where employees keep their records and propose changes, and administration of a versioned organisation chart, reference data and accounts — built from a few shared definitions, not a page per record.

An interactive Python script that proves an identity provider is ready for a client: it rehearses a full PKCE sign-in and sign-out like an application, then checks the tokens it receives against the provider's keys the way an application must.

A laptop and a borrowed Colab GPU talked through a public MQTT broker that anyone could read. Giving that channel an identity took an afternoon on the broker and eight obstacles in the clients — mostly safeguards that were right for the old setup and wrong for the new one.

A failed login in a half-built service is either a misconfigured identity provider or wrong code. I rule out the first by rehearsing a full login with my own tool before writing any app, and found compliant providers still disagree on tokens and claims.