# cache

**Kind:** Function

**Source:** [`src/middleware/cache/index.ts`](https://github.com/honojs/hono/blob/main/src/middleware/cache/index.ts#L183)

**Part of:** [Middleware](subsystem-src-middleware)

Cache Middleware for Hono.

`cache` creates Hono middleware that checks a named Cache API store before running a route handler. For cache misses, it runs the handler, sets the configured `Cache-Control` header, and stores the response for later matching requests.

## Signature

```ts
function cache(options: { cacheName: string | ((c: Context) => Promise<string> | string) wait?: boolean cacheControl?: string vary?: string | string[] keyGenerator?: (c: Context) => Promise<string> | string maxQueryBodySize?: number cacheableStatusCodes?: StatusCode[] onCacheNotAvailable?: ((reason: string) => void) | false }): MiddlewareHandler
```

## Parameters

| Name | Type |
|---|---|
| `options` | `{ cacheName: string | ((c: Context) => Promise<string> | string) wait?: boolean cacheControl?: string vary?: string | string[] keyGenerator?: (c: Context) => Promise<string> | string maxQueryBodySize?: number cacheableStatusCodes?: StatusCode[] onCacheNotAvailable?: ((reason: string) => void) | false }` |

**Returns:** `MiddlewareHandler`

## Diagram

```mermaid
graph LR
  Request[Incoming request] --> Middleware[cache middleware]
  Middleware --> CacheStore[Named Cache API store]
  CacheStore -->|Cache hit| CachedResponse[Cached response]
  CacheStore -->|Cache miss| Handler[Route handler]
  Handler --> Response[Response with Cache-Control]
  Response --> CacheStore
  Response --> Client[Client]
  CachedResponse --> Client
```

## Usage

```ts
import { Hono } from 'hono'
import { cache } from 'hono/cache'

const app = new Hono()

app.get(
  '/articles/:id',
  cache({
    cacheName: 'articles',
    cacheControl: 'max-age=3600',
    wait: true,
  }),
  async (c) => {
    const article = await getArticle(c.req.param('id'))
    return c.json(article)
  }
)

export default app
```

## AI Coding Instructions

- Apply `cache` before the route handler whose response should be stored.
- Set `cacheName` to separate cached responses for different application areas.
- Set `cacheControl` to match the intended client and edge caching policy.
- Use `wait: true` when cache writes should run through the execution context rather than delay the response.
- Ensure cached routes return responses that are safe to reuse for matching requests.