Function memorize

memorize(options?: MemorizeOptions): Memorize

Creates an in-memory cache for an Express application.

Returns a Memorize instance that can be used as per-route middleware, a global app.use() middleware, or a cache management API — all sharing the same underlying store.

Only GET requests are cached. Responses are cached only when the HTTP status code is in the 2xx range. The cache key is req.originalUrl, which includes the query string.

Parameters

options: MemorizeOptions = {}
Global configuration for the cache instance.

Returns Memorize

Example: Per-route middleware

const cache = memorize({ ttl: 30_000 });

app.get('/users', cache(), (req, res) => {
  res.json({ data: users });
});

Example: Global middleware

const cache = memorize({ ttl: 60_000 });
app.use(cache()); // caches all GET routes

Example: Cache invalidation

const cache = memorize({ ttl: 30_000 });

app.post('/users', (req, res) => {
  users.push(req.body);
  cache.delete('/users');
  res.status(201).json(req.body);
});

Example: Event hooks

cache.on(MemorizeEventType.Set,    (e) => console.log('stored',  e.key));
cache.on(MemorizeEventType.Delete, (e) => console.log('deleted', e.key));
cache.on(MemorizeEventType.Expire, (e) => console.log('expired', e.key));
cache.on(MemorizeEventType.Empty,  ()  => console.log('cache is empty'));