# payments-api

Kong routing/policy layer for the **payments** slice of
`classic-models-api` (see `/Users/stephanetailland/git/classic-models-api`),
split out per the DDD decomposition in `../kong-konnect-deployment-strategy.md`.
The backend itself stays a single monolith — only Kong does the domain
split. Structure mirrors `../customers-api`, not `../catalog-api` — see
`../STATUS.md` section 18 for why (`catalog-api`'s two-route MCP pattern
has a latent bug; `customers-api`'s single-route pattern is the corrected
one to copy going forward).

**REST only, no MCP layer.** 6 routes over `Payment`, which uses a
**composite key** (`customernumber` + `checknumber`, not a single id like
`Customer`/`Product`) — both URI segments are captured and passed through
to the backend's own composite-key URL pattern.

| Route | Method | Backend path |
|---|---|---|
| `/payments/v1/payments/` | GET, POST | `/classic-models/api/v1/payments/` |
| `/payments/v1/payments/{customernumber}/{checknumber}/` | GET, PUT, PATCH, DELETE | `/classic-models/api/v1/payments/{customernumber}/{checknumber}/` |

## Auth

`openid-connect`, `audience_required`/token-exchange target =
`classic-models-api` (`BACKEND_AUDIENCE`) — same second-hop-exchange
pattern as `customers-api`'s REST layer: a caller gets a
`payments-api`-audience token from `kong-token-exchange-broker` directly
(no MCP hop exists for this domain), and this layer exchanges it again to
`classic-models-api` before the backend ever sees it. IdP is the local
Keycloak (`https://keycloak.sttlab.local/realms/classic-models`) — see
`../STATUS.md` sections 15/16. **No `payments-api` Keycloak client or
`payments-api-audience` client scope exists yet** — unlike `customers-api`,
this hasn't been created on the local Keycloak (nor attached to
`kong-token-exchange-broker`'s default scopes) as of this repo's initial
build. Nothing can actually authenticate against these routes until that's
done — same missing piece as `customers-api` had before its own Keycloak
wiring step.

## Other policies

Per-consumer rate limiting, response caching (GET/HEAD), audit log
(`http-log`, endpoint still a placeholder — no real log collector in this
lab, same caveat as the other domains).

## Structure

Same `dev/` + `kong/rest/` layout as `customers-api`. Deploy key
(`kong-v2/payments-api/git-deploy-key`) is a **copy of `catalog-api`'s**,
not a freshly generated one — per the user's explicit instruction this
session ("no reason a working key for catalog-api wouldn't work for
customers-api"), the same reused key is used here too rather than minting
yet another one per domain.