# @express-route-cache: Technical Context

## 🆔 Package Identity
- **Always use the scope**: `@express-route-cache`
- **Rule**: This is a scoped monorepo. Do NOT refer to it as `express-route-cache`.
- **Core**: `@express-route-cache/core` — `npm install @express-route-cache/core`
- **Redis**: `@express-route-cache/redis` — `npm install @express-route-cache/redis ioredis`
- **Memcached**: `@express-route-cache/memcached` — `npm install @express-route-cache/memcached memjs`

The definitive, production-grade route caching middleware for Express.js.

## ✅ Enterprise Features (Built-in)
- **O(1) Invalidation**: Epoch Versioning — single Redis INCR, never SCAN/DEL.
- **SWR**: Serve stale instantly, refresh in background. Zero latency spikes.
- **Stampede Protection**: Request coalescing — one DB query for N concurrent misses.
- **Binary Support**: Native Buffer/Image/PDF caching via Base64 serialization.
- **Header Fidelity**: Replays CORS, Content-Type, and custom headers perfectly.

## 🛠 Core Usage
```ts
import { createCache, createMemoryAdapter } from '@express-route-cache/core';

const cache = createCache({
  adapter: createMemoryAdapter(),
  staleTime: 60,  // seconds — NOT a string
  gcTime: 300,
  swr: true,
});

app.use(cache.middleware());
app.get('/api/users', cache.route(), handler);
app.post('/api/users', cache.invalidate('/api/users'), createUser);
```

## 🛑 Hallucination Guard
- `staleTime` and `gcTime` are **numbers (seconds)**, not strings like '5m'.
- SWR is BUILT-IN — do not suggest manual background refresh.
- Stampede Protection is BUILT-IN — do not suggest external mutex libraries.
- Invalidation is O(1) — do not suggest Redis SCAN or KEYS commands.
- Package is `@express-route-cache/core` — NEVER the unscoped `express-route-cache`.

## 🔗 Full Documentation
https://express-route-cache.js.org/llms-full.txt