diff --git a/pyinfinitensor/src/pyinfinitensor/onnx.py b/pyinfinitensor/src/pyinfinitensor/onnx.py
index 832e398c..68d0f110 100644
--- a/pyinfinitensor/src/pyinfinitensor/onnx.py
+++ b/pyinfinitensor/src/pyinfinitensor/onnx.py
@@ -309,6 +309,15 @@ def to_onnx(graph: backend.GraphHandler):
 
     ops = graph.operators()
 
+    names: Dict[Any, str] = dict()
+    count: Dict[backend.OpType, int] = dict()
+
+    for op in ops:
+        ty = op.op_type()
+        names[op] = "{}{}".format(ty.name, count.setdefault(ty, 0) + 1)
+        count[ty] += 1
+    print(names)
+
 
 def parse_onnx(model: onnx.ModelProto):
     print()
diff --git a/src/ffi/ffi_infinitensor.cc b/src/ffi/ffi_infinitensor.cc
index b0de6d08..5a86b56a 100644
--- a/src/ffi/ffi_infinitensor.cc
+++ b/src/ffi/ffi_infinitensor.cc
@@ -21,6 +21,55 @@ void register_operator_timer(py::module &m) {
 #endif
 }
 
+void init_values(py::module &m) {
+#define VALUE(TYPE, NAME) value(#NAME, TYPE::NAME)
+
+    py::enum_<ActType>(m, "ActType")
+        .value("Linear", ActType::None) // None 是 Python 关键字，不能用
+        .VALUE(ActType, Relu)
+        .VALUE(ActType, Sigmoid)
+        .VALUE(ActType, Tanh)
+        .export_values();
+
+    py::enum_<OpType>(m, "OpType")
+        .VALUE(OpType, Unknown)
+        .VALUE(OpType, Conv)
+        .VALUE(OpType, Matmul)
+        .VALUE(OpType, ConvTrans)
+        .VALUE(OpType, G2BMM)
+        .VALUE(OpType, GBMM)
+        .VALUE(OpType, Pad)
+        .VALUE(OpType, Slice)
+        .VALUE(OpType, Concat)
+        .VALUE(OpType, Split)
+        .VALUE(OpType, Transpose)
+        .VALUE(OpType, Extend)
+        .VALUE(OpType, MaxPool)
+        .VALUE(OpType, AvgPool)
+        .VALUE(OpType, Add)
+        .VALUE(OpType, Sub)
+        .VALUE(OpType, Mul)
+        .VALUE(OpType, Div)
+        .VALUE(OpType, Pow)
+        .VALUE(OpType, Gather)
+        .VALUE(OpType, ReduceMean)
+        .VALUE(OpType, Reshape)
+        .VALUE(OpType, Flatten)
+        .VALUE(OpType, Identity)
+        .VALUE(OpType, BatchNorm)
+        .VALUE(OpType, Softmax)
+        .VALUE(OpType, Activation)
+        .VALUE(OpType, Relu)
+        .VALUE(OpType, Sigmoid)
+        .VALUE(OpType, Tanh)
+        .VALUE(OpType, Abs)
+        .VALUE(OpType, Resize)
+        .VALUE(OpType, MemBound)
+        .export_values();
+
+#undef VALUE
+}
+
 void init_graph_builder(py::module &m) {
     using Handler = GraphHandlerObj;
 
@@ -28,14 +77,10 @@ void init_graph_builder(py::module &m) {
     py::class_<RuntimeObj, std::shared_ptr<RuntimeObj>>(m, "Runtime");
     py::class_<CpuRuntimeObj, std::shared_ptr<CpuRuntimeObj>, RuntimeObj>(
         m, "CpuRuntime");
-    py::class_<TensorObj, std::shared_ptr<TensorObj>>(m, "TensorObj");
-    py::class_<OperatorObj, std::shared_ptr<OperatorObj>>(m, "Operator");
-    py::enum_<ActType>(m, "ActType")
-        .value("Linear", ActType::None) // `None` is Python keyword
-        .value("Relu", ActType::Relu)
-        .value("Sigmoid", ActType::Sigmoid)
-        .value("Tanh", ActType::Tanh)
-        .export_values();
+    py::class_<TensorObj, std::shared_ptr<TensorObj>>(m, "TensorObj")
+        .def("src", &TensorObj::getOutputOf, policy::move);
+    py::class_<OperatorObj, std::shared_ptr<OperatorObj>>(m, "Operator")
+        .def("op_type", &OperatorObj::getOpType, policy::move);
     py::class_<Handler>(m, "GraphHandler")
         .def(py::init<Runtime>())
         .def("tensor", py::overload_cast<Shape, int>(&Handler::tensor),
@@ -104,10 +149,8 @@ void init_graph_builder(py::module &m) {
              py::overload_cast<Tensor, Tensor, const vector<int> &,
                                const optional<vector<int>> &>(&Handler::pad),
              policy::move)
-        .def("topo_sort", py::overload_cast<>(&Handler::topo_sort),
-             policy::automatic)
-        .def("operators", py::overload_cast<>(&Handler::operators),
-             policy::move)
+        .def("topo_sort", &Handler::topo_sort, policy::automatic)
+        .def("operators", &Handler::operators, policy::move)
         .def("data_malloc", &Handler::data_malloc, policy::automatic)
         .def("run", &Handler::run, policy::automatic);
 }
@@ -116,5 +159,6 @@ void init_graph_builder(py::module &m) {
 
 PYBIND11_MODULE(backend, m) {
     infini::register_operator_timer(m);
+    infini::init_values(m);
     infini::init_graph_builder(m);
 }