diff --git a/interface/interface.csv b/interface/interface.csv
new file mode 100644
index 0000000..f8171e1
--- /dev/null
+++ b/interface/interface.csv
@@ -0,0 +1,10 @@
+function_name,result_data_type,argument_data_types
+geocode_admin0_polygon,Geometry,"country_name text"
+geocode_admin1_polygon,Geometry,"admin1_name text"
+geocode_admin1_polygon,Geometry,"admin1_name text, country_name text"
+geocode_namedplace_point,Geometry,"city_name text"
+geocode_namedplace_point,Geometry,"city_name text, country_name text"
+geocode_namedplace_point,Geometry,"city_name text, admin1_name text, country_name text"
+geocode_postalcode_polygon,Geometry,"postal_code text, country_name text"
+geocode_postalcode_point,Geometry,"postal_code text, country_name text"
+geocode_ipaddress_point,Geometry,"ip_address text"