diff --git a/tests/test_ci_environment.py b/tests/test_ci_environment.py
new file mode 100644
index 0000000..354a8a1
--- /dev/null
+++ b/tests/test_ci_environment.py
@@ -0,0 +1,10 @@
+"""CI environment validation for integration tests."""
+import os
+
+
+def test_perigon_api_key_format():
+    """Validate that PERIGON_API_KEY follows the expected sk-* convention."""
+    api_key = os.environ.get("PERIGON_API_KEY", "")
+    assert api_key.startswith("sk-"), (
+        f"Expected PERIGON_API_KEY to start with 'sk-', got: {api_key}"
+    )