⚠️ Breaking Change
Impact Score: 7/10
Astro [email protected] — Release Notes & Engineering Impact
Source available — automated, not human-reviewed
Component: astro · Channel: stable. Automated analysis, not a compatibility certification. How this works.
Analysis updated: 2026-11-01.
Breaking-change evidence from the source
- [#15118](https://github.com/withastro/astro/pull/15118) [`cfa382b`](https://github.com/withastro/astro/commit/cfa382b7aa23a9f5a506181c75a0706595208396) Thanks [@florian-lefebvre](https://github.com/florian-lefebvre)! - **BREAKING CHANGE to the experimental Fonts API only**
- [#15117](https://github.com/withastro/astro/pull/15117) [`b1e8e32`](https://github.com/withastro/astro/commit/b1e8e32670ba601d3b3150514173dd7d1bb25650) Thanks [@florian-lefebvre](https://github.com/florian-lefebvre)! - **BREAKING CHANGE to the experimental Fonts API only**
⚡ Executive Summary (TL;DR)
Astro [email protected]. Source highlight: Improves JSDoc annotations for `AstroGlobal`, `AstroSharedContext` and `APIContext` types
Who Does This Impact? (Role-Based Analysis)
💻 Software Engineers & Devs
Check the source notes against the package and APIs you use before upgrading.
📊 Product & Engineering Leads
Use the documented changes to assess relevance to your product; release frequency alone is not a quality measure.
⚙️ DevOps & Security
Verify the target version, runtime requirements and rollback procedure in the official documentation.
⚠️ Breaking Changes & Deprecations (2)
- - [#15118](https://github.com/withastro/astro/pull/15118) [`cfa382b`](https://github.com/withastro/astro/commit/cfa382b7aa23a9f5a506181c75a0706595208396) Thanks [@florian-lefebvre](https://github.com/florian-lefebvre)! - **BREAKING CHANGE to the experimental Fonts API only**
- - [#15117](https://github.com/withastro/astro/pull/15117) [`b1e8e32`](https://github.com/withastro/astro/commit/b1e8e32670ba601d3b3150514173dd7d1bb25650) Thanks [@florian-lefebvre](https://github.com/florian-lefebvre)! - **BREAKING CHANGE to the experimental Fonts API only**
🔧 Bug Fixes & Patches (6)
- Improves JSDoc annotations for `AstroGlobal`, `AstroSharedContext` and `APIContext` types
- Improves rendering performance by grouping render chunks when emitting from async iterables to avoid encoding costs
- Fixes remote images `Etag` header handling by disabling internal cache
- Fixes images not working in development when using setups with port forwarding
- Fixes certain aliases not working when using images in JSON files with the content layer
- **BREAKING CHANGE to the experimental Fonts API only**
📄 View Raw Release Notes (Original Developer Log)
### Patch Changes
- [#15122](https://github.com/withastro/astro/pull/15122) [`b137946`](https://github.com/withastro/astro/commit/b1379466e8c6ded9fbcc3687c7faca4c2d3472b2) Thanks [@florian-lefebvre](https://github.com/florian-lefebvre)! - Improves JSDoc annotations for `AstroGlobal`, `AstroSharedContext` and `APIContext` types
- [#15123](https://github.com/withastro/astro/pull/15123) [`3f58fa2`](https://github.com/withastro/astro/commit/3f58fa20540ee3753158d8d0372affa47775c561) Thanks [@43081j](https://github.com/43081j)! - Improves rendering performance by grouping render chunks when emitting from async iterables to avoid encoding costs
- [#14954](https://github.com/withastro/astro/pull/14954) [`7bec4bd`](https://github.com/withastro/astro/commit/7bec4bdadda1d66da1c7dc0a01ad4412a47337d9) Thanks [@volpeon](https://github.com/volpeon)! - Fixes remote images `Etag` header handling by disabling internal cache
- [#15052](https://github.com/withastro/astro/pull/15052) [`b2bcd5a`](https://github.com/withastro/astro/commit/b2bcd5af28dfb75541f3249b0277b458355395cf) Thanks [@Princesseuh](https://github.com/Princesseuh)! - Fixes images not working in development when using setups with port forwarding
- [#15028](https://github.com/withastro/astro/pull/15028) [`87b19b8`](https://github.com/withastro/astro/commit/87b19b8df49d08ee7a7a1855f3645fe7bebf1997) Thanks [@Princesseuh](https://github.com/Princesseuh)! - Fixes certain aliases not working when using images in JSON files with the content layer
- [#15118](https://github.com/withastro/astro/pull/15118) [`cfa382b`](https://github.com/withastro/astro/commit/cfa382b7aa23a9f5a506181c75a0706595208396) Thanks [@florian-lefebvre](https://github.com/florian-lefebvre)! - **BREAKING CHANGE to the experimental Fonts API only**
Removes the `defineAstroFontProvider()` type helper.
If you are building a custom font provider, remove any occurrence of `defineAstroFontProvider()` and use the `FontProvider` type instead:
```diff
-import { defineAstroFontProvider } from 'astro/config';
-export function myProvider() {
- return defineAstroFontProvider({
- entrypoint: new URL('./implementation.js', import.meta.url)
- });
-};
+import type { FontProvider } from 'astro';
+export function myProvider(): FontProvider {
+ return {
+ entrypoint: new URL('./implementation.js', import.meta.url)
+ },
+}
```
- [#15055](https://github.com/withastro/astro/pull/15055) [`4e28db8`](https://github.com/withastro/astro/commit/4e28db8d125b693039b393111fa48d7bcc913968) Thanks [@delucis](https://github.com/delucis)! - Reduces Astro’s install size by around 8 MB
- [#15088](https://github.com/withastro/astro/pull/15088) [`a19140f`](https://github.com/withastro/astro/commit/a19140fd11efbc635a391d176da54b0dc5e4a99c) Thanks [@martrapp](https://github.com/martrapp)! - Enables the ClientRouter to preserve the original hash part of the target URL during server side redirects.
- [#15117](https://github.com/withastro/astro/pull/15117) [`b1e8e32`](https://github.com/withastro/astro/commit/b1e8e32670ba601d3b3150514173dd7d1bb25650) Thanks [@florian-lefebvre](https://github.com/florian-lefebvre)! - **BREAKING CHANGE to the experimental Fonts API only**
Changes the font format downloaded by default when using the experimental Fonts API. Additionally, adds a new `formats` configuration option to specify which font formats to download.
Previously, Astro was opinionated about which font sources would be kept for usage, mainly keeping `woff2` and `woff` files.
You can now specify what font formats should be downloaded (if available). Only `woff2` files are downloaded by default.
#### What should I do?
If you were previously relying on Astro downloading the `woff` format, you will now need to specify this explicitly with the new `formats` configuration option. Additionally, you may also specify any additional file formats to download if available:
```diff
// astro.config.mjs
import { defineConfig, fontProviders } from 'astro/config'
export default defineConfig({
experimental: {
fonts: [{
name: 'Roboto',
cssVariable: '--font-roboto',
provider: fontProviders.google(),
+ formats: ['woff2', 'woff', 'otf']
}]
}
})
```
- [#15034](https://github.com/withastro/astro/pull/15034) [`8115752`](https://github.com/withastro/astro/commit/811575237d159ceac5d9f0a2ea3bf023df718759) Thanks [@florian-lefebvre](https://github.com/florian-lefebvre)! - Fixes a vite warning log during builds when using npm