# 1.7 — Per-route body size caps (RED)

Phase: 1 — Proxy core
Stage: RED
Depends on: [0.2](0.2-route-configuration.md), [1.1](1.1-reverse-proxy.md)

- [ ] Each route enforces its own configured maximum request body size
- [ ] A body over the cap is rejected with `413` and a body the upstream never sees
- [ ] Rejection happens while reading, not after buffering the whole body into memory
- [ ] A request with a lying or absent `Content-Length` is still capped by bytes actually read
- [ ] A body at exactly the cap is accepted and proxied intact
- [ ] The rejection is logged with a reason distinguishing it from other rejections
- [ ] No global default cap silently applies to a route that failed to declare one — that is a config error, per 0.2

nginx in front is configured with `proxy-body-size: 0`, meaning it enforces no limit
at all, so the gateway is the only place a cap exists. Embedding and rerank callers
can send large batches legitimately, which is why the cap is per route rather than
one number for the whole surface.

## Verify

```bash
go test ./internal/proxy/... -run TestBodySizeCap -v
# expected: passes — a body one byte over the route cap returns 413 and the stub
# upstream records zero requests; a body exactly at the cap returns the stub's 200
```