diff --git a/geomagio/geomag_types.py b/geomagio/geomag_types.py
new file mode 100644
index 0000000000000000000000000000000000000000..a50e2804e5baf21454dbdaf22f75254c51bd70ff
--- /dev/null
+++ b/geomagio/geomag_types.py
@@ -0,0 +1,6 @@
+from typing_extensions import Literal
+
+DataInterval = Literal["tenhertz", "second", "minute", "hour", "day", "month"]
+DataType = Literal[
+    "adjusted", "definitive", "provisional", "quasi-definitive", "reported", "variation"
+]