diff --git a/python/obitools3/dms/capi/build_reference_db.pxd b/python/obitools3/dms/capi/build_reference_db.pxd
new file mode 100755
index 0000000..4b60eb3
--- /dev/null
+++ b/python/obitools3/dms/capi/build_reference_db.pxd
@@ -0,0 +1,12 @@
+#cython: language_level=3
+
+
+cdef extern from "build_reference_db.h" nogil:
+
+    int build_reference_db(const char* dms_name,
+                           const char* refs_view_name,
+                           const char* taxonomy_name,
+                           const char* o_view_name,
+                           const char* o_view_comments,
+                           double threshold)
+