# Shared backend library

This is a Go library module, not an executable. It provides database connections,
transactions and repository primitives, errors, structured logging, generic HTTP
responses, configuration and rate-limit helpers. It contains no customer, session,
verification or Sendico domain models and imports no executable SXCHNGE module.

`product` consumes it through a local module replacement. A future backoffice
executable can consume the same infrastructure independently.

Run `go test -race ./...` and `go vet ./...` here, or use the root Make targets to
validate all implemented backend modules.

`messaging/` contains the locally adapted Sendico NATS connection and durable transport adapters. Executables consume `messaging/runtime`; they do not open their own NATS connections. See [notifications provenance](../notifications/PROVENANCE.md) for selected upstream source.