The change overhauls the entitlement/check API by migrating legacy Express routers into a unified Hono‐based handleCheck route, adds a publicKeyMiddleware to support publishable keys alongside the existing secret‐key flow, and tightens Zod/OpenAPI import and testing guidelines. It reshapes routing and authentication layers across 82 files—consolidating logic into reusable utilities, deprecating old endpoints, and enforcing consistent schema registration—so developers must update imports and configuration accordingly. Given the sheer volume of additions and absence of any CI checks or new tests, there’s a real risk of breaking existing integrations, unhandled edge cases, and incomplete validation of the new flows.