Netlify Skew Protection Test Project

This project demonstrates the Netlify skew protection feature that adds X-Netlify-Deploy-ID headers to internal fetch requests in Astro.

Live Demo: https://skew-protection-test.netlify.app/

What this tests

1. Actions: Client-side calls to Astro Actions include the deploy ID header
2. View Transitions: Navigation between pages includes the deploy ID header
3. Server Islands: (Not included in this demo, but supported)

Setup

The project uses preview packages from PR #14543. Install them with:

npm i https://pkg.pr.new/astro@14543
npm i https://pkg.pr.new/@astrojs/netlify@14543

Or if the packages are already in package.json:

npm install

Local Development

npm run dev

Note: In local development, the deploy ID will show as "local-development" since there's no actual DEPLOY_ID environment variable.

Deploy to Netlify

1. Create a new site on Netlify
2. Connect your repository or drag-and-drop the project folder
3. Netlify will automatically detect the Astro framework
4. Deploy!

How to Verify

On Netlify (after deployment):

1. Open your deployed site
2. Open browser Developer Tools (F12)
3. Go to the Network tab
4. Click the "Call Action" button
   • Look for the POST /_actions/greet request
   • Check the Request Headers for X-Netlify-Deploy-ID
5. Click the "other page" link
   • Look for the HTML fetch request
   • Check the Request Headers for X-Netlify-Deploy-ID

What to expect:

• The X-Netlify-Deploy-ID header should appear in all internal fetch requests
• The value should match the current deployment ID
• This ensures that during deployments, clients always fetch resources from the same deployment version

Files to Check

After building, you can verify the skew protection configuration:

1. .netlify/v1/skew-protection.json - Contains the skew protection configuration
2. Built JavaScript files - Will include the header injection code

Preview Release

This project uses the preview release from PR #14543:

{
  "astro": "^5.14.5-pr14543.20251014135916",
  "@astrojs/netlify": "^6.5.12-pr14543.20251014135916"
}

Update these to the latest snapshot versions as needed from the PR.