From b0f3de0ab9637f0241778a30d0ffb23e8582b0eb Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Mon, 28 Sep 2026 23:10:07 +0000
Subject: [PATCH] Build PR previews with site.url set to the preview URL

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RBeXFA4VVU7vGuBVLRcPbZ
---
 .github/workflows/main.yml | 13 ++++++++++++-
 README-DEPLOYMENT.md       |  1 +
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index e088b872..4a271789 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -43,12 +43,23 @@ jobs:
         ruby-version: 3.3.4
         bundler-cache: true # runs 'bundle install' and caches installed gems automatically
     - name: Build Jekyll website
+      env:
+        EVENT_NAME: ${{ github.event_name }}
+        PR_NUMBER: ${{ github.event.pull_request.number }}
       run: |
         set -xo pipefail
         rm -rf _site/*
         gem install bundler -v 2.6.3
         bundle install
-        bundle exec jekyll build
+        config=_config.yml
+        if [ "$EVENT_NAME" = "pull_request" ]; then
+          # Absolute links (site.url) must point at the preview deployment,
+          # not at the production site. The alias matches the
+          # --branch=pr-<number> used by the preview job.
+          echo "url: https://pr-${PR_NUMBER}.aeamain.pages.dev" > "$RUNNER_TEMP/_config_preview.yml"
+          config="$config,$RUNNER_TEMP/_config_preview.yml"
+        fi
+        bundle exec jekyll build --config "$config"
     - name: Generate agent instruction file
       run: python3 .github/scripts/generate_agent_md.py
     - name: Upload site artifact
diff --git a/README-DEPLOYMENT.md b/README-DEPLOYMENT.md
index f26098f8..16534e8c 100644
--- a/README-DEPLOYMENT.md
+++ b/README-DEPLOYMENT.md
@@ -80,6 +80,7 @@ Once the secrets exist, every PR from a repo branch (not a fork) will get:
 
 - A live preview at a Cloudflare Pages URL specific to that PR
   (`--branch=pr-<PR number>`), rebuilt on every push to the PR.
+- A site built with `url` set to that preview URL, so absolute links stay on the preview instead of pointing at production
 - A PR comment with the preview link, edited in place on each new commit
   rather than re-posted.