# Astro astro@6.3.7 — Release & Upgrade Intelligence
- **Product:** Astro (https://astro.build)
- **Version:** astro@6.3.7
- **Released:** May 21, 2026
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/astro/updates/astro-6.3.7/

## Executive Summary (TL;DR)
Astro astro@6.3.7. Source highlight: Fixes request body handling in the Node adapter when `req.body` is a `Buffer`, `Uint8Array`, or `ArrayBuffer`. Previously, binary body data was incorrectly JSON-stringified (producing `{"type":"Buffer","data":[...]}`) instead of being passed through directly. This affected libraries like `serverless

## Bug Fixes
- Fixes request body handling in the Node adapter when `req.body` is a `Buffer`, `Uint8Array`, or `ArrayBuffer`. Previously, binary body data was incorrectly JSON-stringified (producing `{"type":"Buffer","data":[...]}`) instead of being passed through directly. This affected libraries like `serverless-http` that set `req.body` to a `Buffer`.
- Fixes `vite.build.minify`, `vite.build.sourcemap`, and `vite.build.rollupOptions.output` (e.g. `compact`) being ignored for client-side builds. These top-level Vite build options are now properly forwarded to the client environment, with environment-specific overrides (`vite.environments.client.build.*`) taking priority when set.
- Fixes custom elements in MDX files bypassing the renderer pipeline. Custom elements (tags containing hyphens like `<my-element>`) in `.mdx` files are now routed through registered renderers for SSR, matching the behavior of `.astro` files. If no renderer claims the element, it falls back to rendering as raw HTML.
- Fixes dynamic routes returning 400 Bad Request when the URL contains a literal `%` character, such as paths built with `encodeURIComponent('%?.pdf')`
- Fixes a v6 regression where `astro:i18n` could not be imported from client `<script>` blocks.

## Upgrade Command
```bash
npm install --save-exact astro@6.3.7
```