Astro

Fixed CSS hot module replacement breaking after navigating between pages with ClientRouter, and a CSP violation when using both security.csp and experimental.clientPrerender with data-astro-prefetch links. Fixed a regression where content collection reference() fields silently accepted non-existent entry IDs—Astro now logs errors for missing references. Plus fixes for middleware HMR, video/audio elements after view transitions, incremental build hash collisions, and prerender environment 500 errors.

The astro preview --background flag starts preview servers as background processes, making it easier to manage from scripts and AI coding agents. Astro now offers experimental support for incremental static builds via experimental.incrementalBuild, which can skip regenerating static pages when module dependencies and cache keys are unchanged. Also widened the AstroPrerenderer render() return type to report incremental-build metadata, added relative path support in logger.entrypoint, optional digest property on content entries, and session: false option to tree-shake session runtime from serverless bundles.

Fixed concurrent static builds failing to generate i18n rewrite fallbacks for dynamic routes, and stale dev CSS after editing component style blocks and CSS files. experimental.collectionStorage now supports configurable chunk sizes, and the Astro compiler was bumped to the latest version.

Fixed a bug where an error during request finalization could prevent a response from being sent. Also fixed custom logger.entrypoint failing to load at runtime in built server bundles, action path resolution treating function properties as routable segments, and custom 404/500 pages not rendering when middleware rewrites targeted routes returning empty responses.

Fixed duplicate CSS files being emitted when prerendered and server-rendered pages share the same styles (e.g., shared layouts with Tailwind). The SSR build now reuses the CSS asset filename from the prerender build when backed by the same source modules. Also fixed missing scoped styles for child components inside client:only islands in production builds.

Fixed image optimization during astro build using too many parallel processes in CPU-limited containers. Builds now respect the container's CPU limit, reducing peak memory usage and avoiding out-of-memory crashes.

Fixed a bug where mutated Astro.locals during the request lifecycle were lost and not passed to custom error pages (404.astro/500.astro), and prevented an unhandled promise rejection from the prefetch fetch fallback on flaky connections in WebKit. Also updated the cookie dependency to v2, which no longer percent-encodes cookie values made entirely of URL-safe characters.

Fixed encoded request paths being routed incorrectly when using domain-based i18n.

Adds a new deferRender option to the glob() content loader that defers rendering of markdown entries until they are actually used in a page, reducing memory usage during builds for large collections with heavy post-processing. Also adds support for more specific CSP directives (script-src-elem, script-src-attr, style-src-elem, style-src-attr) through a new kind option in both config and runtime CSP APIs, plus an experimental collectionStorage: 'chunked' option to split the data store across smaller files for very large collections. Fixes a JSON logger crash in non-Node runtimes and several other smaller issues.

Fixed the first browser visit after astro dev starts triggering an immediate full page reload. Client islands now reliably recover from transient import failures during component loading, a problem that previously affected React components in astro dev mode.

Fixed astro preview --open not opening a browser when using an adapter with a custom preview entrypoint like @astrojs/cloudflare, and astro dev --force not replacing an already-running dev server. Updated the Astro compiler to fix many regressions, improved rendering performance for pages with many component instances, and exposed the AstroRuntimeLogger interface for proper runtime typing.

Fixed a CSS module scoped-name hash mismatch in astro dev when using vite.css.transformer: 'lightningcss' with content collections, where components would get different class name hashes in the element and injected style tag. Also fixed a dev server memory leak and crashes when requests with .html or /index.html suffixes matched dynamic endpoint routes.

Fixed route generation crashing or silently dropping segments when a dynamic param's value is 0 (the generator used truthy checks instead of checking for undefined). Also fixed the security.checkOrigin check to apply consistently to Astro Actions and on-demand endpoints regardless of middleware composition order, and removed a spurious React 19 "Invalid hook call" warning in dev mode when JSX renderer include options were set.

Fixed an error that could occur after dev server restarts when using adapters like @astrojs/cloudflare, where requests would fail with a missing pre-bundled dependency error. Also fixed style tags from components being silently dropped when an await appeared before the component in .astro markup, ClientRouter wiping head elements after page transitions with server:defer components, prefetch not working inside server:defer components, and the background dev server failing to start in certain setups like bun workspaces.

Transition directive values are now HTML-escaped when rendered on hydrated islands, and trailing slash handling for dynamic file endpoints in dev mode is fixed. Also fixes getCollection() returning empty for large content collections (500k+ entries) and hardens forwarded header validation against allowedDomains.

Fixed a bug where an error thrown inside one route's getStaticPaths() would prevent other valid routes from being matched in dev mode, and HMR now works for action files during development. Also fixed localized custom error pages in i18n projects to use correct routes like /pt/404 for missing localized pages.

Patch Changes

• Updated dependencies [3b5e994]:
  • @astrojs/markdown-satteri@0.3.2

Fixed astro dev incorrectly starting in background mode for Warp terminal users and failing on Windows. Responsive image CSS now respects user-defined @layer blocks by wrapping generated styles in @layer astro.images. Background dev server with --host now displays all network addresses.

Astro now uses Vite 8, the Rust-based compiler (@astrojs/compiler-rs) by default, and Sätteri as the default Markdown processor instead of remark/rehype. HTML compression now uses JSX rules by default, stripping whitespace around elements while preserving meaningful inline spacing. The @astrojs/db package and related CLI commands (astro db, astro login, astro link, astro init) have been removed. Advanced routing is enabled by default and now uses src/fetch.ts as the entrypoint instead of src/app.ts. Background dev server management is available via astro dev --background, astro dev stop, astro dev status, and astro dev logs for AI coding agents.

Route caching is now stable and moves from experimental flags to top-level configuration options. The experimental.cache and experimental.routeRules flags are replaced by cache and routeRules. Also fixes Vite and Rolldown build warnings.