What Changed In Astro 7

Astro 7 is mostly about speed and making previously experimental server features stable.

flowchart TD
    astro7[Astro 7] --> build["Faster builds"]
    astro7 --> routing["Request control"]
    astro7 --> cache["Stable route caching"]
    astro7 --> agents["Agent-friendly dev"]

    build --> vite["Vite 8 + Rolldown"]
    build --> compiler["Rust .astro compiler"]
    build --> satteri["Sätteri Markdown"]
    build --> queued["Queued rendering"]

    routing --> fetchFile["src/fetch.ts"]
    cache --> astroCache["Astro.cache"]
    agents --> bg["astro dev --background"]

The Big Pieces

Area	Astro 6	Astro 7
Bundler	Vite 7-era toolchain	Vite 8 with Rolldown/Oxc under the hood
`.astro` compiler	Go compiler by default	Rust compiler only
Markdown/MDX	unified pipeline by default	Sätteri by default, unified opt-in
Route caching	experimental	stable Astro API
Advanced routing	experimental	stable and enabled by default
`src/fetch.ts`	ordinary project file	reserved advanced routing entrypoint
AI dev server	normal foreground dev server	agent detection can start background mode

What Most Projects Need To Do

Most projects start here:

npx @astrojs/upgrade
npm run build

Then inspect the real failure modes:

build errors from stricter .astro parsing
missing spaces between inline elements after the compressHTML: 'jsx' default
Markdown plugin output changes
stale experimental config flags
accidental src/fetch.ts conflicts
removed @astrojs/db or astro:transitions internals

Gotcha: Vite 8 is a breaking dependency upgrade, but Astro app authors usually only feel it if they use custom Vite plugins, Vite internals, or advanced build config.

What Not To Do

Do not treat every new feature as something to adopt immediately.

Feature	Default stance
Advanced routing	Ignore until you need custom request ordering
CDN cache providers	Treat as experimental host-specific integration
Sätteri plugin migration	Only port plugins you actually need
`compressHTML: true` rollback	Use only if visual whitespace fixes are too risky