diff --git a/.github/scripts/hide-old-deploy-comments.mjs b/.github/scripts/hide-old-deploy-comments.mjs
new file mode 100644
index 0000000..b969711
--- /dev/null
+++ b/.github/scripts/hide-old-deploy-comments.mjs
@@ -0,0 +1,31 @@
+// Minimizes previous deploy-preview comments so only the latest is visible.
+// Called from preview-deploy.yml via actions/github-script.
+
+export default async function run({ github, context, prNumber }) {
+  const comments = await github.paginate(github.rest.issues.listComments, {
+    owner: context.repo.owner,
+    repo: context.repo.repo,
+    issue_number: prNumber,
+  });
+
+  await Promise.all(
+    comments
+      .filter(
+        (c) =>
+          c.user.login === "github-actions[bot]" &&
+          c.body.includes("<!-- deploy-preview -->")
+      )
+      .map((c) =>
+        github.graphql(
+          `
+          mutation($id: ID!) {
+            minimizeComment(input: { subjectId: $id, classifier: OUTDATED }) {
+              minimizedComment { isMinimized }
+            }
+          }
+        `,
+          { id: c.node_id }
+        )
+      )
+  );
+}
diff --git a/.github/workflows/pages.yml b/.github/workflows/pages.yml
deleted file mode 100644
index 64a86b9..0000000
--- a/.github/workflows/pages.yml
+++ /dev/null
@@ -1,57 +0,0 @@
-name: Deploy Pages
-
-on:
-  push:
-    branches: [main]
-  workflow_dispatch:
-
-permissions:
-  contents: read
-  pages: write
-  id-token: write
-
-concurrency:
-  group: pages
-  cancel-in-progress: false
-
-jobs:
-  build:
-    name: Build site
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v5
-
-      - name: Setup Node.js
-        uses: actions/setup-node@v6
-        with:
-          node-version: "24"
-          cache: "npm"
-
-      - name: Install dependencies
-        run: npm ci
-
-      - name: Build GAP website
-        run: npm run build
-
-      - name: Configure Pages
-        uses: actions/configure-pages@v6
-
-      - name: Upload Pages artifact
-        uses: actions/upload-pages-artifact@v5
-        with:
-          path: _site
-
-  deploy:
-    name: Deploy site
-    needs: build
-    runs-on: ubuntu-latest
-    environment:
-      name: github-pages
-      url: ${{ steps.deployment.outputs.page_url }}
-
-    steps:
-      - name: Deploy to GitHub Pages
-        id: deployment
-        uses: actions/deploy-pages@v5
diff --git a/.github/workflows/preview-build.yml b/.github/workflows/preview-build.yml
new file mode 100644
index 0000000..06d1239
--- /dev/null
+++ b/.github/workflows/preview-build.yml
@@ -0,0 +1,41 @@
+name: Build Preview
+
+on:
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+concurrency:
+  group: preview-build-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    name: Build site
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+
+      - name: Setup Node.js
+        uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7
+        with:
+          node-version: "24"
+          cache: "npm"
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build GAP website
+        run: npm run build
+
+      - name: Upload build artifact
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
+        with:
+          name: preview-build
+          path: _site
+          include-hidden-files: true
+          retention-days: 3
diff --git a/.github/workflows/preview-deploy.yml b/.github/workflows/preview-deploy.yml
new file mode 100644
index 0000000..5956201
--- /dev/null
+++ b/.github/workflows/preview-deploy.yml
@@ -0,0 +1,98 @@
+name: Deploy Preview
+
+on:
+  workflow_run:
+    workflows: ["Build Preview"]
+    types: [completed]
+
+permissions:
+  contents: read
+  actions: read
+  pull-requests: write
+
+jobs:
+  deploy:
+    name: Deploy preview to Cloudflare
+    runs-on: ubuntu-latest
+    if: ${{ github.event.workflow_run.conclusion == 'success' && github.event.workflow_run.event == 'pull_request' }}
+
+    steps:
+      - name: Checkout wrangler config
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          ref: main
+          sparse-checkout: |
+            wrangler.jsonc
+            .github/scripts
+
+      # Security: actions/download-artifact handles zip extraction safely
+      # (immune to zip-slip), and the artifact only contains static HTML/CSS/JS
+      # built by the unprivileged preview-build workflow.
+      - name: Download build artifact
+        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8
+        with:
+          name: preview-build
+          run-id: ${{ github.event.workflow_run.id }}
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          path: _site
+
+      - name: Get PR number
+        id: pr
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          PR_NUM=$(gh pr list --repo "${{ github.repository }}" \
+            --head "${{ github.event.workflow_run.head_branch }}" \
+            --json number --jq '.[0].number')
+          if ! [[ "$PR_NUM" =~ ^[0-9]+$ ]]; then
+            echo "::error::Could not determine PR number"
+            exit 1
+          fi
+          echo "number=$PR_NUM" >> "$GITHUB_OUTPUT"
+
+      # Security: Wrangler is configured for static asset serving only (see
+      # wrangler.jsonc). The uploaded content is pre-built HTML/CSS/JS with no
+      # server-side execution capability.
+      - name: Deploy preview to Cloudflare Workers
+        id: deploy
+        uses: cloudflare/wrangler-action@ebbaa1584979971c8614a24965b4405ff95890e0 # v4
+        with:
+          apiToken: ${{ secrets.CLOUDFLARE_API_TOKEN }}
+          accountId: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}
+          command: versions upload --no-bundle --preview-alias "pr-${{ steps.pr.outputs.number }}" --message "PR #${{ steps.pr.outputs.number }} preview (${{ github.event.workflow_run.head_sha }})"
+
+      - name: Hide old deploy preview comments
+        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9
+        with:
+          script: |
+            const { default: run } = await import('${{ github.workspace }}/.github/scripts/hide-old-deploy-comments.mjs');
+            await run({ github, context, prNumber: ${{ steps.pr.outputs.number }} });
+
+      - name: Comment on PR (success)
+        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9
+        with:
+          script: |
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: ${{ steps.pr.outputs.number }},
+              body: [
+                '<!-- deploy-preview -->',
+                '### 🚀 Deploy Preview',
+                '',
+                '- **This commit:** ${{ steps.deploy.outputs.deployment-url }}',
+                '- **This PR** <sub>(kept up to date)</sub>: https://pr-${{ steps.pr.outputs.number }}-gaps.graphql-foundation.workers.dev'
+              ].join('\n')
+            });
+
+      - name: Comment on PR (failure)
+        if: failure()
+        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9
+        with:
+          script: |
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: ${{ steps.pr.outputs.number }},
+              body: 'Deploy preview failed.\n\n```\ngh run view ${{ github.run_id }} --repo ${{ github.repository }} --log-failed\n```'
+            });
diff --git a/wrangler.jsonc b/wrangler.jsonc
new file mode 100644
index 0000000..7ffd0bb
--- /dev/null
+++ b/wrangler.jsonc
@@ -0,0 +1,8 @@
+{
+  "$schema": "node_modules/wrangler/config-schema.json",
+  "name": "gaps",
+  "compatibility_date": "2026-05-23",
+  "assets": {
+    "directory": "./_site"
+  }
+}