# Astro astro@5.17.1 — Release & Upgrade Intelligence
- **Product:** Astro (https://astro.build)
- **Version:** astro@5.17.1
- **Released:** Jan 29, 2026
- **Impact Score:** 7/10
- **Breaking Changes:** Source flagged
- **Canonical Analysis:** https://changelogs.us/astro/updates/astro-5.17.1/

## Executive Summary (TL;DR)
Astro astro@5.17.1. Source highlight: **BREAKING CHANGE to the experimental Fonts API only**

## Breaking Changes & Deprecations
- -   [#15334](https://github.com/withastro/astro/pull/15334) [`d715f1f`](https://github.com/withastro/astro/commit/d715f1f88777a4ce0fb61c8043cccfbac2486ab4) Thanks [@florian-lefebvre](https://github.com/florian-lefebvre)! - **BREAKING CHANGE to the experimental Fonts API only**

## Bug Fixes
- **BREAKING CHANGE to the experimental Fonts API only**
- On prerendered routes, read the file using `node:fs`
- On server rendered routes, fetch files using URLs from `fontData` and `context.url`

## Upgrade Command
```bash
npm install --save-exact astro@5.17.1
```