diff --git a/.github/workflows/claude.yml b/.github/workflows/claude.yml
index 3a90b46..bb951be 100644
--- a/.github/workflows/claude.yml
+++ b/.github/workflows/claude.yml
@@ -6,6 +6,8 @@ on:
   pull_request_review_comment:
     types: [created]
 
+permissions: {}
+
 jobs:
   claude:
     if: contains(github.event.comment.body, '@claude')
diff --git a/.github/workflows/scorecard.yml b/.github/workflows/scorecard.yml
new file mode 100644
index 0000000..ef2f585
--- /dev/null
+++ b/.github/workflows/scorecard.yml
@@ -0,0 +1,39 @@
+name: Scorecard
+
+# No push trigger: the weekly run on main publishes the results, so rescanning
+# after every merge only repeated it.
+on:
+  branch_protection_rule:
+  schedule:
+    - cron: "35 6 * * 1"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  analysis:
+    name: Scorecard analysis
+    timeout-minutes: 15
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      security-events: write # Upload Scorecard results to code scanning.
+      id-token: write # Publish results for the public Scorecard badge.
+    steps:
+      - name: Check out source
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+
+      - name: Run Scorecard
+        uses: ossf/scorecard-action@fa7117db83c52d787ae5a89f350999701505d78e # v2.5.0
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          publish_results: true
+
+      - name: Upload results to code scanning
+        uses: github/codeql-action/upload-sarif@9b3254085494b55a0f7c4c2b3d2d52cc712ce370 # v4.39.1
+        with:
+          sarif_file: results.sarif