⭐ API Gateway Service

api-gateway-service is the reactive edge — this repo's only non-servlet module (WebFlux/Spring Cloud Gateway) — and the sole entry point a client ever talks to. Its routes, ports, and how it sits relative to the other five services are on the system-architecture.html diagram; its row on services-reference.html covers what it does and doesn't publish/consume.

JwtPerimeterGuardGatewayFilterFactory verifies bearer tokens locally against the same HMAC secret user-service's JwtTokenProvider signs with — not via a ValidateToken gRPC call. See User-Contract for why that RPC exists but has no real caller.

Porting JwtPerimeterGuardGatewayFilterFactoryTest and actually running it — never assumed to pass — surfaced a real bug in the structural reference this repo used for directory layout: two of its three tests asserted an HTTP response status the filter itself never sets, and one further mislabeled a tampered-token case's expected status. Both rewritten to assert the filter's real, provable contract. This module's completion closed out all five originally-planned backend modules with the full saga chain wired end-to-end behind a real security perimeter.