diff --git a/gtsam/discrete/discrete.i b/gtsam/discrete/discrete.i
new file mode 100644
index 000000000..68c2e5079
--- /dev/null
+++ b/gtsam/discrete/discrete.i
@@ -0,0 +1,24 @@
+//*************************************************************************
+// basis
+//*************************************************************************
+
+namespace gtsam {
+
+
+// typedef pair<size_t, size_t> DiscreteKey;
+
+#include <gtsam/discrete/DiscreteFactor.h>
+class DiscreteFactor {
+};
+
+#include <gtsam/discrete/DecisionTreeFactor.h>
+class DecisionTreeFactor {
+  DecisionTreeFactor();
+};
+
+#include <gtsam/discrete/DiscreteFactorGraph.h>
+class DiscreteFactorGraph {
+  DiscreteFactorGraph();
+};
+
+}  // namespace gtsam
diff --git a/python/CMakeLists.txt b/python/CMakeLists.txt
index c3524adad..3781a16ba 100644
--- a/python/CMakeLists.txt
+++ b/python/CMakeLists.txt
@@ -54,6 +54,7 @@ set(ignore
 set(interface_headers
     ${PROJECT_SOURCE_DIR}/gtsam/gtsam.i
     ${PROJECT_SOURCE_DIR}/gtsam/base/base.i
+    ${PROJECT_SOURCE_DIR}/gtsam/discrete/discrete.i
     ${PROJECT_SOURCE_DIR}/gtsam/geometry/geometry.i
     ${PROJECT_SOURCE_DIR}/gtsam/linear/linear.i
     ${PROJECT_SOURCE_DIR}/gtsam/nonlinear/nonlinear.i
diff --git a/python/gtsam/preamble/discrete.h b/python/gtsam/preamble/discrete.h
new file mode 100644
index 000000000..56a07cfdd
--- /dev/null
+++ b/python/gtsam/preamble/discrete.h
@@ -0,0 +1,14 @@
+/* Please refer to:
+ * https://pybind11.readthedocs.io/en/stable/advanced/cast/stl.html
+ * These are required to save one copy operation on Python calls.
+ *
+ * NOTES
+ * =================
+ *
+ * `PYBIND11_MAKE_OPAQUE` will mark the type as "opaque" for the pybind11
+ * automatic STL binding, such that the raw objects can be accessed in Python.
+ * Without this they will be automatically converted to a Python object, and all
+ * mutations on Python side will not be reflected on C++.
+ */
+
+#include <pybind11/stl.h>
diff --git a/python/gtsam/specializations/discrete.h b/python/gtsam/specializations/discrete.h
new file mode 100644
index 000000000..da8842eaf
--- /dev/null
+++ b/python/gtsam/specializations/discrete.h
@@ -0,0 +1,12 @@
+/* Please refer to:
+ * https://pybind11.readthedocs.io/en/stable/advanced/cast/stl.html
+ * These are required to save one copy operation on Python calls.
+ *
+ * NOTES
+ * =================
+ *
+ * `py::bind_vector` and similar machinery gives the std container a Python-like
+ * interface, but without the `<pybind11/stl.h>` copying mechanism. Combined
+ * with `PYBIND11_MAKE_OPAQUE` this allows the types to be modified with Python,
+ * and saves one copy operation.
+ */