Independent Go module with an operational HTTP shell and selected, adapted Sendico foundations. Sendico remains an external financial-services provider; there are no Sendico module imports, shared databases or sibling-path dependencies. See the architecture and service plan and reuse provenance.

Run and validate

Requires Go 1.26 or later. From the repository root:

make test-backend
make lint-backend
make run-backend

The default address is 127.0.0.1:8082; override with SXCHNGE_HTTP_ADDR. GET /healthz reports process health. GET /readyz deliberately returns 503 with not_configured: persistence, authentication and Sendico are not connected. No product routes return dummy success. The process handles SIGINT/SIGTERM with bounded graceful shutdown. Production transport must terminate HTTPS.

Present components

cmd/bff, internal/httpapi: HTTP process, timeouts and operational endpoints.
internal/browser: explicit HTTPS origin/CSRF policy and Secure HttpOnly host-only session cookie. Apply this policy to every future browser mutation; it is not yet connected to product routes because those do not exist.
internal/credential: random opaque credentials and storage digests. Never use this helper for passwords or short OTP codes.
internal/evidence: confined server-generated object keys; not a substitute for ownership, upload validation or private storage controls.

Only the standard library is required. Larger adapted flows, persistence, provider DTOs/mappers, email and live integration follow the plan in separate contributions. Source-derived components evolve independently inside this repo.