diff --git a/include/ion/node.h b/include/ion/node.h
index 1939bc50..5f813163 100644
--- a/include/ion/node.h
+++ b/include/ion/node.h
@@ -91,7 +91,7 @@ class Node {
         return Port(name, impl_->id);
     }
 
-    std::string id() const {
+    const std::string& id() const {
         return impl_->id;
     }
 
@@ -99,7 +99,7 @@ class Node {
         return impl_->id;
     }
 
-    std::string name() const {
+    const std::string& name() const {
         return impl_->name;
     }
 
@@ -107,7 +107,7 @@ class Node {
         return impl_->name;
     }
 
-    Halide::Target target() const {
+    const Halide::Target& target() const {
         return impl_->target;
     }
 
@@ -115,7 +115,7 @@ class Node {
         return impl_->target;
     }
 
-    std::vector<Param> params() const {
+    const std::vector<Param>& params() const {
         return impl_->params;
     }
 
@@ -123,7 +123,7 @@ class Node {
         return impl_->params;
     }
 
-    std::vector<Port> ports() const {
+    const std::vector<Port>& ports() const {
         return impl_->ports;
     }
 
diff --git a/include/ion/port.h b/include/ion/port.h
index 2be7496e..50ce6020 100644
--- a/include/ion/port.h
+++ b/include/ion/port.h
@@ -27,25 +27,26 @@ class Port {
         std::string node_id;
         std::vector<Halide::Internal::Parameter> params;
 
-        Impl() : name(), type(), dimensions(0), node_id(), params() {}
+        Impl() {}
+
+        Impl(const std::string& n, const Halide::Type& t, int32_t d, const std::string& nid)
+            : name(n), type(t), dimensions(d), node_id(nid), params({ Halide::Internal::Parameter(type, dimensions != 0, dimensions, argument_name(node_id, name)) })
+        {}
     };
 
  public:
      friend class Node;
      friend class nlohmann::adl_serializer<Port>;
 
-     Port() : impl_(new Impl), index_(-1) {};
-     Port(const std::shared_ptr<Impl>& impl) : impl_(impl), index_(-1) {};
+     Port() : impl_(new Impl("", Halide::Type(), 0, "")), index_(-1) {}
+     Port(const std::shared_ptr<Impl>& impl) : impl_(impl), index_(-1) {}
 
      /**
       * Construct new port for scalar value.
       * @arg k: The key of the port which should be matched with BuildingBlock Input/Output name.
       * @arg t: The type of the value.
       */
-     Port(const std::string& n, Halide::Type t) : impl_(new Impl), index_(-1) {
-         impl_->name = n;
-         impl_->type = t;
-     }
+     Port(const std::string& n, Halide::Type t) : impl_(new Impl(n, t, 0, "")), index_(-1) {}
 
      /**
       * Construct new port for vector value.
@@ -53,11 +54,7 @@ class Port {
       * @arg t: The type of the element value.
       * @arg d: The dimension of the port. The range is 1 to 4.
       */
-     Port(const std::string& n, Halide::Type t, int32_t d) : impl_(new Impl), index_(-1) {
-        impl_->name = n;
-        impl_->type = t;
-        impl_->dimensions = d;
-     }
+     Port(const std::string& n, Halide::Type t, int32_t d) : impl_(new Impl(n, t, d, "")), index_(-1) {}
 
      const std::string& name() const { return impl_->name; }
      std::string& name() { return impl_->name; }
@@ -97,21 +94,24 @@ class Port {
      template<typename T>
      void bind(T v) {
          auto i = index_ == -1 ? 0 : index_;
-         impl_->params.resize(i+1, Halide::Internal::Parameter{type(), dimensions() != 0, dimensions(), argument_name(node_id(), name())});
+         impl_->params.resize(i+1);
+         impl_->params[i] = Halide::Internal::Parameter{type(), dimensions() != 0, dimensions(), argument_name(node_id(), name())};
          impl_->params[i].set_scalar(v);
      }
 
      template<typename T>
      void bind(const Halide::Buffer<T>& buf) {
          auto i = index_ == -1 ? 0 : index_;
-         impl_->params.resize(i+1, Halide::Internal::Parameter{type(), dimensions() != 0, dimensions(), argument_name(node_id(), name())});
+         impl_->params.resize(i+1);
+         impl_->params[i] = Halide::Internal::Parameter{type(), dimensions() != 0, dimensions(), argument_name(node_id(), name())};
          impl_->params[i].set_buffer(buf);
      }
 
      template<typename T>
      void bind(const std::vector<Halide::Buffer<T>>& bufs) {
-         impl_->params.resize(bufs.size(), Halide::Internal::Parameter{type(), dimensions() != 0, dimensions(), argument_name(node_id(), name())});
+         impl_->params.resize(bufs.size());
          for (size_t i=0; i<bufs.size(); ++i) {
+             impl_->params[i] = Halide::Internal::Parameter{type(), dimensions() != 0, dimensions(), argument_name(node_id(), name())};
              impl_->params[i].set_buffer(bufs[i]);
          }
      }
@@ -130,10 +130,7 @@ class Port {
     /**
      * This port is bound with some node.
      */
-     Port(const std::string& n, const std::string& ni) : impl_(new Impl), index_(-1) {
-         impl_->name = n;
-         impl_->node_id = ni;
-     }
+     Port(const std::string& n, const std::string& nid) : impl_(new Impl(n, Halide::Type(), 0, nid)), index_(-1) {}
 
      std::shared_ptr<Impl> impl_;
 
diff --git a/src/serializer.h b/src/serializer.h
index 2a2500ad..8ca31c74 100644
--- a/src/serializer.h
+++ b/src/serializer.h
@@ -29,13 +29,13 @@ template <>
 class adl_serializer<ion::Param> {
 public:
 static void to_json(json& j, const ion::Param& v) {
-    j["key_"] = v.key();
-    j["val_"] = v.val();
+    j["key"] = v.key();
+    j["val"] = v.val();
 }
 
 static void from_json(const json& j, ion::Param& v) {
-    v.key() = j["key_"].get<std::string>();
-    v.val() = j["val_"].get<std::string>();
+    v.key() = j["key"].get<std::string>();
+    v.val() = j["val"].get<std::string>();
 }
 };
 
@@ -43,21 +43,26 @@ template<>
 class adl_serializer<ion::Port> {
  public:
      static void to_json(json& j, const ion::Port& v) {
-         j["name_"] = v.name();
-         j["type_"] = static_cast<halide_type_t>(v.type());
-         j["dimensions_"] = v.dimensions();
-         j["index_"] = v.index();
-         j["node_id_"] = v.node_id();
-         j["impl_"] = reinterpret_cast<uintptr_t>(v.impl_.get());
+         j["name"] = v.name();
+         j["type"] = static_cast<halide_type_t>(v.type());
+         j["dimensions"] = v.dimensions();
+         j["index"] = v.index();
+         j["node_id"] = v.node_id();
+         j["array_size"] = v.params().size();
+         j["impl"] = reinterpret_cast<uintptr_t>(v.impl_.get());
      }
 
      static void from_json(const json& j, ion::Port& v) {
-         v = ion::Port(ion::Port::find_impl(j["impl_"].get<uintptr_t>()));
-         v.name() = j["name_"].get<std::string>();
-         v.type() = j["type_"].get<halide_type_t>();
-         v.dimensions() = j["dimensions_"];
-         v.index() = j["index_"];
-         v.node_id() = j["node_id_"].get<std::string>();
+         v = ion::Port(ion::Port::find_impl(j["impl"].get<uintptr_t>()));
+         v.name() = j["name"].get<std::string>();
+         v.type() = j["type"].get<halide_type_t>();
+         v.dimensions() = j["dimensions"];
+         v.node_id() = j["node_id"].get<std::string>();
+         v.params() = std::vector<Halide::Internal::Parameter>(
+             j["array_size"],
+             Halide::Internal::Parameter(v.type(), v.dimensions() != 0, v.dimensions(), ion::argument_name(v.node_id(), v.name()))
+         );
+         v.index() = j["index"];
      }
 };
 
diff --git a/test/c_api.cc b/test/c_api.cc
index 35751226..d853cbf7 100644
--- a/test/c_api.cc
+++ b/test/c_api.cc
@@ -114,6 +114,7 @@ int main()
             if (ret != 0)
                 return ret;
 
+
             ret = ion_port_destroy(extent1);
             if (ret != 0)
                 return ret;
diff --git a/test/inverted_dep.cc b/test/inverted_dep.cc
index 52b30eff..32a634eb 100644
--- a/test/inverted_dep.cc
+++ b/test/inverted_dep.cc
@@ -22,72 +22,78 @@ int main()
                       "params": [],
                       "ports": [
                         {
-                          "dimensions_": 0,
-                          "name_": "output",
-                          "index_" : -1,
-                          "node_id_": "1310589d-1448-4107-ac1d-67c32f482906",
-                          "impl_": 1,
-                          "type_": {
+                          "dimensions": 0,
+                          "name": "output",
+                          "index" : -1,
+                          "node_id": "1310589d-1448-4107-ac1d-67c32f482906",
+                          "array_size": 1,
+                          "impl": 1,
+                          "type": {
                             "bits": 0,
                             "code": 3,
                             "lanes": 0
                           }
                         },
                         {
-                          "dimensions_": 0,
-                          "name_": "min0",
-                          "index_" : -1,
-                          "node_id_": "",
-                          "impl_": 2,
-                          "type_": {
+                          "dimensions": 0,
+                          "name": "min0",
+                          "index" : -1,
+                          "node_id": "",
+                          "array_size": 1,
+                          "impl": 2,
+                          "type": {
                             "bits": 32,
                             "code": 0,
                             "lanes": 1
                           }
                         },
                         {
-                          "dimensions_": 0,
-                          "name_": "extent0",
-                          "index_" : -1,
-                          "node_id_": "",
-                          "impl_": 3,
-                          "type_": {
+                          "dimensions": 0,
+                          "name": "extent0",
+                          "index" : -1,
+                          "node_id": "",
+                          "array_size": 1,
+                          "impl": 3,
+                          "type": {
                             "bits": 32,
                             "code": 0,
                             "lanes": 1
                           }
                         },
                         {
-                          "dimensions_": 0,
-                          "name_": "min1",
-                          "index_" : -1,
-                          "node_id_": "",
-                          "impl_": 5,
-                          "type_": {
+                          "dimensions": 0,
+                          "name": "min1",
+                          "index" : -1,
+                          "node_id": "",
+                          "array_size": 1,
+                          "impl": 5,
+                          "type": {
                             "bits": 32,
                             "code": 0,
                             "lanes": 1
                           }
                         },
                         {
-                          "dimensions_": 0,
-                          "name_": "extent1",
-                          "index_" : -1,
-                          "node_id_": "",
-                          "impl_": 6,
-                          "type_": {
+                          "dimensions": 0,
+                          "name": "extent1",
+                          "index" : -1,
+                          "node_id": "",
+                          "array_size": 1,
+                          "impl": 6,
+                          "type": {
                             "bits": 32,
                             "code": 0,
                             "lanes": 1
                           }
                         },
                         {
-                          "dimensions_": 0,
-                          "name_": "v",
-                          "index_" : -1,
-                          "node_id_": "",
-                          "impl_": 7,
-                          "type_": {
+                          "dimensions": 0,
+                          "name": "v",
+                          "index" : -1,
+                          "node_id": "",
+                          "array_size": 1,
+                          "impl": 7,
+                          "type": {
                             "bits": 32,
                             "code": 0,
                             "lanes": 1