---
title: "Caching and privacy · Affordances"
description: "The Markdown is the page that caller would see, and it's only cached when the page is public."
url: "https://affordances.vercel.app/docs/plugins/md/caching"
image: "https://affordances.vercel.app/og/docs/plugins/md/caching"
lang: "en"
---

# Caching and privacy

The Markdown is the page that caller would see, and it's only cached when the page is public.

The handler forwards the caller's `cookie`, `authorization`, and `accept-language` headers, so a signed-in agent gets the page that person would see. Everything about that response stays personal:

- With a cookie or bearer token, or when the page is `private` or `no-store`, or sets a cookie, the Markdown is sent with `Cache-Control: private, no-store`.
- Otherwise it keeps the page's own `Cache-Control`.
- Every response has `Vary: Accept`, `X-Affordances-Tokens` with an estimate of its length in tokens, and a `Link` to the canonical page when it has one.

The status code is the page's. A redirect to the same site stays in Markdown (to the target's `.md`); one to another origin is passed on, never followed. A page that takes longer than 10 seconds answers `504`, and one larger than 6 MB answers `413`.

## Behind a proxy

The handler fetches pages from the request's own origin. When a proxy changes it, set `AFFORDANCES_MD_ORIGIN`, or build the handler with options:

```ts title="app/api/affordances/md/[[...path]]/route.ts"
import { createMdHandler } from '@affordances/md/next'

export const GET = createMdHandler({ origin: 'http://localhost:3000', timeout: 5000 })
```

| Option     | Default       | Description                                                |
| ---------- | ------------- | ---------------------------------------------------------- |
| `origin`   | the request's | Where to fetch pages from                                  |
| `timeout`  | `10000`       | Milliseconds before answering `504`                        |
| `maxBytes` | 6 MB          | The largest page it converts                               |
| `append`   | none          | More Markdown after the page's, such as an actions summary |