# SXCHNGE BFF

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](../docs/architecture/bff.md) and
[reuse provenance](PROVENANCE.md).

## Run and validate

Requires Go 1.26 or later. From the repository root:

```sh
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.