# `src/`

Application source. HealthLog is a Next.js 16 App Router project (`output: "standalone"`, React 19, TypeScript strict). The path alias `@/*` resolves to this directory. Everything a request touches lives under here; the layout below follows the request flow rather than alphabetical order.

## Request flow

```
client → src/proxy.ts → src/app/<route>/route.ts → src/lib/api-handler.ts → handler body → src/lib/api-response.ts → client
```

- **`proxy.ts`** — the HTTP edge (Next.js 16's renamed `middleware`). Public-path allowlist, demo-mode mutation block, server-side onboarding redirect, worker-only refusal, `x-request-id` + CSP nonce generation, every security header.
- **`app/`** — App Router pages (RSC by default) and API routes. Every API route wraps its handler in `apiHandler`. See [`app/README.md`](app/README.md).
- **`lib/`** — the server/runtime toolkit: `apiHandler`, auth, crypto, rollups, AI, notifications, pg-boss jobs, integrations, rate limiting. See [`lib/README.md`](lib/README.md).
- **`components/`** — React components (shadcn/ui new-york, kebab-case files). See [`components/README.md`](components/README.md).

## Other directories

- **`hooks/`** — shared React hooks (`use-` prefix, kebab-case).
- **`types/`** — shared TypeScript declarations.
- **`generated/prisma/`** — the generated Prisma client (do not edit; regenerated by `prisma generate`). Imported as `@/generated/prisma`.
- **`instrumentation.ts`** — Next.js startup hook; boots the pg-boss worker registry and boot-time backfill queues.
- **`__tests__/`** — cross-cutting unit tests; most tests live in `__tests__/` folders next to the code they cover.

## Conventions

See [`../CLAUDE.md`](../CLAUDE.md) for the full set. The load-bearing ones: RSC by default (`"use client"` only when a hook/state/browser API needs it); every API route wraps `apiHandler` and parses its body with Zod `safeParse`; `userId` is always narrowed from session or Bearer, never accepted as a body field; TanStack Query keys come only from `src/lib/query-keys/`; outbound HTTP goes through `src/lib/safe-fetch.ts`.