Astro, the web framework for building content-driven websites, has annouced Astro 6 Beta, introducing a completely redesigned development server, first-class Cloudflare Workers support, and several new stable APIs including live content collections and Content Security Policy support.
Astro 6 Beta brings significant changes to how developers work with the framework, including a refactored development server built on Vite's Environment API, stable live content collections for real-time data updates, and built-in CSP support. The release also includes breaking changes such as requiring Node 22+ and removing several deprecated APIs.
One of the headline features in Astro 6 is the completely redesigned astro dev development server. The new server leverages Vite's Environment API to run applications inside the same runtime as production, closing the gap between development and deployment environments. Previously, code that worked locally could behave differently once deployed, and platform-specific features often could not be tested until after deployment. By unifying the development and production code paths, the Astro team has already discovered and fixed numerous subtle bugs that existed only in development or only in production.
The most complete example of what the new development server makes possible is support for Cloudflare Workers. With Astro 6 Beta, astro dev can now run applications using workerd, Cloudflare's open-source JavaScript runtime, which is the same runtime that powers Cloudflare Workers in production. This means developers can now develop directly against real platform APIs rather than simulations or polyfills. When running astro dev with Cloudflare support, developers now have access to Durable Objects, KV Namespaces, R2 Storage, Workers Analytics Engine, and environment variables, all with Hot Module Replacement support.
Access to Cloudflare bindings is now direct using the cloudflare:workers module, as shown in the beta blog article:
import { env } from "cloudflare:workers";
const kv = env.MY_KV_NAMESPACE;
await kv.put("visits", "1");
const visits = await kv.get("visits");
Live content collections, which were experimental in Astro 5.10, are now stable in Astro 6. These build on Astro's type-safe content collections to enable updating data in real time without requiring a rebuild, making them ideal for frequently updating data sources such as live stock prices or inventory. The API is designed to feel familiar to those already using Astro's build-time content collections, but with explicit error handling for the realities of live data requests.
Content Security Policy support, previously experimental in Astro 5.9, is now stable. CSP was Astro's most upvoted feature request and helps protect sites against cross-site scripting and other code injection attacks. The feature works in all Astro render modes and is compatible with all official adapters, automatically generating CSP headers or meta elements including hashes of scripts and styles.
Astro 6 includes several breaking changes as the team cleans up deprecated APIs. The most significant changes include removing Astro.glob(), requiring Node 22 or later, and updates to the Cloudflare adapter that remove Astro.locals.runtime in favor of direct platform API access. The team has published a comprehensive upgrade guide with detailed migration steps for each breaking change.
The release has generated some discussions within the community, with one user on reddit commenting on the long list of breaking changes (specifically noting the earlier alpha release):
Whew. What a huge list of breaking changes.…
Which prompted a response from Astro Core Maintainer, Sarah Rainsberger:
Most of which won't affect everyone, at least!
Who goes onto explain the rationale for such a detailed list of breaking changes:
...I firmly believe that everything that could possibly break someone's project should be included on that page... whether that "project" is a regular static website, or a theme you built, or a complex integration.
Elsewhere on Hacker News, commenters highlighted that Astro is among the first frameworks to support Cloudflare's Vite plugin:
Cloudflare released their vite plugin which makes it effortless for frameworks that use the vite env API to run inside workerd... Nextjs has no support, the draft PR to add support for Sveltekit has been parked until the next major version, Astro only just added support in their beta 6.0 release 3 days ago
Compared to other meta-frameworks like Next.js and SvelteKit, Astro has distinguished itself with its focus on content-driven websites and minimal client-side JavaScript by default. While Next.js emphasizes React and full-stack capabilities and SvelteKit focuses on the Svelte ecosystem, Astro remains framework-agnostic with official support for React, Vue, Svelte, and other UI frameworks through its islands architecture.
Astro is an open-source web framework designed for building content-driven websites including blogs, marketing sites, and e-commerce. The framework emphasizes performance through minimal client-side JavaScript, rendering as much content as possible at build time or on-demand on the server.