diff --git a/_config.yml b/_config.yml
new file mode 100644
index 000000000..e435ef648
--- /dev/null
+++ b/_config.yml
@@ -0,0 +1,10 @@
+# Exclude internal tooling and developer documentation from the Jekyll site build.
+# Without this, Jekyll's Liquid engine tries to process Jinja2 {% %} tags in
+# scripts/docs/*.md and crashes with "Unknown tag" errors.
+exclude:
+  - scripts/
+  - venv/
+  - generated/
+  - experimental/
+  - "*.py"
+  - Makefile