diff --git a/.github/actions/protect-nyc-config/action.yaml b/.github/actions/protect-nyc-config/action.yaml
new file mode 100644
index 000000000..1dcdcb42d
--- /dev/null
+++ b/.github/actions/protect-nyc-config/action.yaml
@@ -0,0 +1,71 @@
+name: Protect NYC config
+description: Block all edits to .nycrc.json files in root and all packages
+
+runs:
+  using: composite
+  steps:
+    - name: Skip non-PR events
+      if: github.event_name != 'pull_request'
+      shell: bash
+      run: echo "Not a pull_request event; skipping Protect NYC config action."
+
+    - name: Show basic PR info
+      if: github.event_name == 'pull_request'
+      shell: bash
+      run: |
+        echo "PR number: ${{ github.event.number }}"
+        echo "PR author: ${{ github.event.pull_request.user.login }}"
+        echo "Draft: ${{ github.event.pull_request.draft }}"
+
+    - name: Detect .nycrc.json changes
+      if: github.event_name == 'pull_request'
+      id: detect
+      shell: bash
+      env:
+        FILES_API: ${{ github.api_url }}/repos/${{ github.repository }}/pulls/${{ github.event.number }}/files?per_page=100
+        GITHUB_TOKEN: ${{ github.token }}
+      run: |
+        echo "Checking PR #${{ github.event.number }} file list for .nycrc.json changes..."
+        RESPONSE=$(curl -sS -H "Authorization: Bearer $GITHUB_TOKEN" \
+          -H "Accept: application/vnd.github+json" \
+          "$FILES_API")
+        echo "Files in PR:"
+        echo "$RESPONSE" | jq -r '.[].filename' || echo "Failed to parse response"
+        
+        # Check for any .nycrc.json files (root or in packages)
+        NYCRC_FILES=$(echo "$RESPONSE" | jq -r '.[].filename' | grep -E '\.nycrc(\.json)?$' || true)
+        
+        if [ -n "$NYCRC_FILES" ]; then
+          echo "nycrc-changed=true" >> "$GITHUB_OUTPUT"
+          echo "nycrc-files<<EOF" >> "$GITHUB_OUTPUT"
+          echo "$NYCRC_FILES" >> "$GITHUB_OUTPUT"
+          echo "EOF" >> "$GITHUB_OUTPUT"
+          echo "✗ .nycrc.json modifications detected in:"
+          echo "$NYCRC_FILES" | sed 's/^/  - /'
+          echo "BLOCKING"
+        else
+          echo "nycrc-changed=false" >> "$GITHUB_OUTPUT"
+          echo "✓ No .nycrc.json modifications detected"
+        fi
+
+    - name: Skip when .nycrc.json unchanged
+      if: github.event_name == 'pull_request' && steps.detect.outputs.nycrc-changed != 'true'
+      shell: bash
+      run: echo "Skipping protection check because no .nycrc.json files were modified."
+
+    - name: Skip check for draft PRs
+      if: github.event_name == 'pull_request' && steps.detect.outputs.nycrc-changed == 'true' && github.event.pull_request.draft == true
+      shell: bash
+      run: echo "PR is in draft state; skipping protection check."
+
+    - name: Block .nycrc.json modifications
+      if: github.event_name == 'pull_request' && steps.detect.outputs.nycrc-changed == 'true' && github.event.pull_request.draft == false
+      shell: bash
+      run: |
+        echo "ERROR: Modifications to .nycrc.json files are not allowed." >&2
+        echo "The following protected files were modified:" >&2
+        echo "${{ steps.detect.outputs.nycrc-files }}" | sed 's/^/  - /' >&2
+        echo "" >&2
+        echo "These files are protected and cannot be changed via pull request." >&2
+        exit 1
+
diff --git a/.github/workflows/main.yaml b/.github/workflows/main.yaml
index 9a24380e2..68373e4eb 100644
--- a/.github/workflows/main.yaml
+++ b/.github/workflows/main.yaml
@@ -5,13 +5,31 @@ permissions:
   contents: write
   issues: read
 
-on: [push]
+on:
+  push:
+  pull_request:
+    types: [opened, synchronize, ready_for_review, reopened]
 
 env:
   CI_BUILD_NUM: ${{ github.run_id }}
   CI_BRANCH: ${{ github.ref_name }}
 
 jobs:
+  protect-nyc-config:
+    if: github.event_name == 'pull_request'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: read
+    steps:
+      - name: Check out
+        uses: actions/checkout@v5
+        with:
+          persist-credentials: 'false'
+
+      - name: Protect NYC config
+        uses: ./.github/actions/protect-nyc-config
+
   test:
     name: Test
     runs-on: ubuntu-latest
@@ -34,7 +52,7 @@ jobs:
         uses: ./.github/actions/lint-test-coverage
 
       - name: Semantic Release (Dry Run)
-        if: github.ref != 'refs/heads/main'
+        if: github.event_name == 'push' && github.ref != 'refs/heads/main'
         run: npm run semantic-release-dry
         env:
           GITHUB_TOKEN: ${{ secrets.ADOBE_BOT_GITHUB_TOKEN }}
@@ -44,7 +62,7 @@ jobs:
     name: Release
     runs-on: ubuntu-latest
     needs: test
-    if: github.ref == 'refs/heads/main'
+    if: github.event_name == 'push' && github.ref != 'refs/heads/main'
     steps:
       - name: Check out
         uses: actions/checkout@v5