# @astrojs/cloudflare An SSR adapter for use with Cloudflare Pages Functions targets. Write your code in Astro/Javascript and deploy to Cloudflare Pages. In your `astro.config.mjs` use: ```js import { defineConfig } from 'astro/config'; import cloudflare from '@astrojs/cloudflare'; export default defineConfig({ output: 'server', adapter: cloudflare() }); ``` ## Enabling Preview In order for preview to work you must install `wrangler` ```sh $ pnpm install wrangler --save-dev ``` It's then possible to update the preview script in your `package.json` to `"preview": "wrangler pages dev ./dist"` ## Streams Some integrations such as [React](https://github.com/withastro/astro/tree/main/packages/integrations/react) rely on web streams. Currently Cloudflare Pages functions are in beta and don't support the `streams_enable_constructors` feature flag. In order to work around this: - install the `"web-streams-polyfill"` package - add `import "web-streams-polyfill/es2018";` to the top of the front matter of every page which requires streams, such as server rendering a React component.