Show HN: Kiosk, a first-class AI assistants' intefrace to online services

Kiosk is an open, Apache 2.0, self-hosted protocol that lets personal AI assistants register with online services without email or password, using per-service Ed25519 keys, OAuth client registration, client assertions and DPoP. Instead of CAPTCHAs, services charge a memory-hard proof of work at registration and every 10th call, with fewer proofs granted for good reputation measured by default as spend. It also covers signed AP2 v0.2 payments through the service's own Stripe account and a WebSocket event stream, and ships a specification, an assistant skill, a reference implementation and seven demo operators.