diff --git a/Makefile b/Makefile
index a1e5bc8..ec1b968 100644
--- a/Makefile
+++ b/Makefile
@@ -30,7 +30,7 @@ rebuild_imnodes:
 # writes ttf fonts fron ./fonts/ to C compressed arrays in C source files
 # builds static library from font arrays definitions
 embed_fonts:
-	@cbuild/call_task.sh embed_fonts
+	@cbuild/call_task.sh embed_fonts 2>&1 | tee make_raw.log
 
 rebuild_all: rebuild_kerep rebuild_imgui rebuild_imnodes embed_fonts
 
diff --git a/src/GraphModel/Attribute.cpp b/src/GraphModel/Attribute.cpp
index e707fd1..5ffb1e3 100644
--- a/src/GraphModel/Attribute.cpp
+++ b/src/GraphModel/Attribute.cpp
@@ -3,7 +3,15 @@
 namespace GraphC::GraphModel {
 
 Attribute::Attribute(id_t _id, Node* _parent_node, Attribute::Type _type, std::string _title) 
-    : id(_id), parent_node(_parent_node), type(_type), title(_title) 
+    : type(_type), id(_id), parent_node(_parent_node), title(_title) 
 {}
 
+const RBTree<id_t, Edge*>& Attribute::getIncomingEdges() const {
+    return incoming_edges;
+}
+
+const RBTree<id_t, Edge*>& Attribute::getOutgoingEdges() const {
+    return outgoing_edges;
+}
+
 }
diff --git a/src/GraphModel/Edge.cpp b/src/GraphModel/Edge.cpp
index 92cbe65..59988c5 100644
--- a/src/GraphModel/Edge.cpp
+++ b/src/GraphModel/Edge.cpp
@@ -3,7 +3,7 @@
 namespace GraphC::GraphModel {
 
 Edge::Edge(id_t _id, id_t _from_attr_id, id_t _to_attr_id) 
-    : id(_id), from_attr_id(_from_attr_id), to_attr_id(_to_attr_id)
+    : id(_id), to_attr_id(_to_attr_id), from_attr_id(_from_attr_id)
 {}
 
 }
diff --git a/src/GraphModel/Graph.cpp b/src/GraphModel/Graph.cpp
index a0774f8..b379fc8 100644
--- a/src/GraphModel/Graph.cpp
+++ b/src/GraphModel/Graph.cpp
@@ -1,47 +1,168 @@
 #include "GraphModel.hpp"
+#include "../UsefulException.hpp"
+#include "../format.hpp"
 
 namespace GraphC::GraphModel {
 
 Graph::Graph() 
 {}
 
-Graph::Graph(RBTree<id_t, Node>& _nodes, RBTree<id_t, Edge>& _edges)
+Graph::Graph(RBTree<id_t, Node>&& _nodes, RBTree<id_t, Edge>&& _edges)
     : nodes(_nodes), edges(_edges)
 {}
 
-RBTree<id_t, Node>& Graph::getNodes(){
+
+const RBTree<id_t, Node>& Graph::getNodes() const {
     return nodes;
 }
 
-RBTree<id_t, Edge>& Graph::getEdges(){
+Node* Graph::createNode(Node& n){
+    Node* result = nullptr;
+    useful_assert(nodes.tryAdd(n.id, n, &result),
+        format("can't create node with id %i", n.id));
+    return result;
+}
+Node* Graph::createNode(Node&& n){
+    return createNode(n);
+}
+
+bool Graph::tryGetNode(id_t node_id, Node** result) const {
+    return nodes.tryGet(node_id, result);
+}
+
+void Graph::deleteNode(Node& n){
+    for(const auto& attr_p : n.attributes)
+        deleteAttribute(*attr_p.second);
+    useful_assert(nodes.tryDelete(n.id),
+        format("can't delete node with id %i", n.id));
+}
+
+void Graph::deleteNode(Node&& n){
+    deleteNode(n);
+}
+
+bool Graph::tryDeleteNode(id_t node_id){
+    Node* n = nullptr;
+    if(!nodes.tryGet(node_id, &n))
+        return false;
+    
+    deleteNode(*n);
+    return true;
+}
+
+
+const RBTree<id_t, Edge>& Graph::getEdges() const {
     return edges;
 }
 
-
-bool tryCreateEdge(Attribute& from, Attribute& to, Edge&& result);
-bool tryGetEdge(id_t edge_id, Edge&& result);
-bool tryDeleteEdge(id_t edge_id);
-
-void Graph::deleteNode(id_t node_id){
-    if(nodes.erase(node_id) < 1)
-        throw UsefulException("can't erase node with id"+toString_i64(node_id));
+Edge* Graph::createEdge(Attribute& from, Attribute& to){
+    id_t id = id_gen.getNext();
+    Edge* e = nullptr;
+    useful_assert(edges.tryAdd(id, Edge(id, from.id, to.id), &e),
+        format("can't create edge with id %i",id));
+    
+    useful_assert(from.incoming_edges.tryAdd(id, e, nullptr), 
+        format("edge with id %i already exists in Attribute::incoming_edges", id));
+    
+    useful_assert(to.outgoing_edges.tryAdd(id, e, nullptr), 
+        format("edge with id %i already exists in Attribute::outgoing_edges", id));
+    return e;
 }
 
-void Graph::deleteEdge(id_t edge_id){
+Edge* Graph::createEdge(Attribute&& from, Attribute&& to){
+    return createEdge(from, to);
+}
 
+bool Graph::tryCreateEdge(id_t from_attr_id, id_t to_attr_id, Edge** result){
+    Attribute* from;
+    if(!tryGetAttribute(from_attr_id, &from))
+        return false;
+    Attribute* to;
+    if(!tryGetAttribute(to_attr_id, &to))
+        return false;
+    Edge* e = createEdge(*from, *to);
+    if(result)
+        *result = e;
+    return true;
+}
+
+bool Graph::tryGetEdge(id_t edge_id, Edge** result) const {
+    return edges.tryGet(edge_id, result);
+}
+
+void Graph::deleteEdge(Edge& e){
+    Attribute* a = nullptr;
+    useful_assert(tryGetAttribute(e.from_attr_id, &a), 
+        format("source attribute with id %i was not found in Graph::nodes", e.from_attr_id));
+    a->outgoing_edges.tryDelete(e.id);
+
+    useful_assert(tryGetAttribute(e.to_attr_id, &a), 
+        format("destination attribute with id %i was not found in Graph::nodes", e.to_attr_id));
+    a->incoming_edges.tryDelete(e.id);
+
+    useful_assert(edges.tryDelete(e.id), 
+        format("can't delete attribute with id %i", e.id));
+}
+
+void Graph::deleteEdge(Edge&& e){
+    deleteEdge(e);
+}
+
+bool Graph::tryDeleteEdge(id_t edge_id){
+    Edge* e;
+    if(!edges.tryGet(edge_id, &e))
+        return false;
+
+    deleteEdge(*e);
+    return true;
 }
 
 
-bool Graph::tryGetAttribute(id_t attr_id, Attribute*& result){
-    for(auto&& p_node : nodes){
-        auto&& node_attrs = p_node.second.getAttributes();
-        auto&& it = node_attrs.find(attr_id);
-        if(it != node_attrs.end()){
-            result = &it->second;
-            return true;
-        }
+const RBTree<id_t, Attribute>& Graph::getAttributes() const {
+    return attributes;
+}
+
+bool Graph::tryGetAttribute(id_t attr_id, Attribute** result) const {
+    return attributes.tryGet(attr_id, result);
+}
+
+Attribute* Graph::createAttribute(Attribute& a){
+    Attribute* result = nullptr;
+    useful_assert(attributes.tryAdd(a.id, a, &result),
+        format("can't create attribute with id %i to Graph", a.id));
+    useful_assert(a.parent_node->attributes.tryAdd(a.id, result, nullptr), 
+        format("can't add attribute with id %i to Node", a.id));
+    return result;
+}
+
+Attribute* Graph::createAttribute(Attribute&& a){
+    return createAttribute(a);
+}
+
+void Graph::deleteAttribute(Attribute& a){
+    for(const auto& edge_p : a.incoming_edges){
+        useful_assert(edges.tryDelete(edge_p.second->id),
+            format("can't find edge with id %i", edge_p.second->id));
     }
-    return false;
+    for(const auto& edge_p : a.outgoing_edges){
+        useful_assert(edges.tryDelete(edge_p.second->id), 
+            format("can't find edge with id %i", edge_p.second->id));
+    }
+    useful_assert(attributes.tryDelete(a.id),
+        format("can't delete attribute with id %i", a.id));
+}
+
+void Graph::deleteAttribute(Attribute&& a){
+    deleteAttribute(a);
+}
+
+bool Graph::tryDeleteAttribute(id_t attr_id){
+    Attribute* a;
+    if(!attributes.tryGet(attr_id, &a))
+        return false;
+    
+    deleteAttribute(*a);
+    return true;
 }
 
 }
\ No newline at end of file
diff --git a/src/GraphModel/GraphModel.hpp b/src/GraphModel/GraphModel.hpp
index 436919f..b71432a 100644
--- a/src/GraphModel/GraphModel.hpp
+++ b/src/GraphModel/GraphModel.hpp
@@ -17,28 +17,38 @@ public:
     id_t getNext();
 };
 
-typedef struct Node Node;
+typedef class Node Node;
+typedef class Attribute Attribute;
 typedef struct Edge Edge;
+typedef class Graph Graph;
 
 class Attribute {
-    std::vector<std::shared_ptr<Edge>> incoming_edges;
-    std::vector<std::shared_ptr<Edge>> outgoing_edges;
+    friend class Graph;
+
+    // pointers to instances in RBTree::edges
+    RBTree<id_t, Edge*> incoming_edges;
+    RBTree<id_t, Edge*> outgoing_edges;
 
 public:
     enum class Type {
-        Input, Output, Static
+        Static, Input, Output
     };
 
     const Attribute::Type type;
     const id_t id;
-    const Node* parent_node;
+    Node *const parent_node;
     std::string title;
 
     Attribute(id_t _id, Node* _parent_node, Attribute::Type _type, std::string _title);
+
+    const RBTree<id_t, Edge*>& getIncomingEdges() const;
+    const RBTree<id_t, Edge*>& getOutgoingEdges() const;
 };
 
 class Node {
-    RBTree<id_t, Attribute> attributes;
+    friend class Graph;
+    // pointers to Attributes in Graph::attributes
+    RBTree<id_t, Attribute*> attributes;
 
 public:
     const id_t id;
@@ -46,10 +56,7 @@ public:
 
     Node(id_t _id, std::string _title);
     
-    RBTree<id_t, Attribute>& getAttributes();
-    bool tryCreateAttribute(IdGenerator id_gen, Attribute*& result);
-    bool tryGetAttribute(id_t attr_id, Attribute*& result);
-    bool tryDeleteAttribute(id_t attr_id);
+    const RBTree<id_t, Attribute*>& getAttributes() const;
 };
 
 struct Edge {
@@ -61,30 +68,57 @@ struct Edge {
 };
 
 class Graph {
-    friend class Attribute;
-    friend class Node;
-    friend class Edge;
-
     RBTree<id_t, Node> nodes;
     RBTree<id_t, Edge> edges;
+    RBTree<id_t, Attribute> attributes;
 
 public:
     IdGenerator id_gen;
 
     Graph();
-    Graph(RBTree<id_t, Node>& _nodes, RBTree<id_t, Edge>& _edges);
+    Graph(RBTree<id_t, Node>&& _nodes, RBTree<id_t, Edge>&& _edges);
 
-    RBTree<id_t, Node>& getNodes();
-    bool tryCreateNode(std::string _title, Node*& result);
-    bool tryGetNode(id_t node_id, Node*& result);
+
+    const RBTree<id_t, Node>& getNodes() const;
+
+    Node* createNode(Node& n);
+    Node* createNode(Node&& n);
+
+    ///@param result nullable
+    bool tryGetNode(id_t node_id, Node** result) const;
+    
+    void deleteNode(Node& n);
+    void deleteNode(Node&& n);
     bool tryDeleteNode(id_t node_id);
 
-    RBTree<id_t, Edge>& getEdges();
-    bool tryCreateEdge(Attribute& from, Attribute& to, Edge*& result);
-    bool tryGetEdge(id_t edge_id, Edge*& result);
+
+    const RBTree<id_t, Edge>& getEdges() const;
+
+    Edge* createEdge(Attribute& from, Attribute& to);
+    Edge* createEdge(Attribute&& from, Attribute&& to);
+
+    ///@param result nullable
+    bool tryCreateEdge(id_t from_attr_id, id_t to_attr_id, Edge** result);
+
+    ///@param result nullable
+    bool tryGetEdge(id_t edge_id, Edge** result) const;
+
+    void deleteEdge(Edge& e);
+    void deleteEdge(Edge&& e);
     bool tryDeleteEdge(id_t edge_id);
 
-    bool tryGetAttribute(id_t attr_id, Attribute*& result);
+    
+    const RBTree<id_t, Attribute>& getAttributes() const;
+
+    Attribute* createAttribute(Attribute& attr);
+    Attribute* createAttribute(Attribute&& attr);
+
+    ///@param result nullable
+    bool tryGetAttribute(id_t attr_id, Attribute** result) const;
+
+    void deleteAttribute(Attribute& a);
+    void deleteAttribute(Attribute&& a);
+    bool tryDeleteAttribute(id_t attr_id);
 };
 
 }
\ No newline at end of file
diff --git a/src/GraphModel/Node.cpp b/src/GraphModel/Node.cpp
index cc497b9..b72eba5 100644
--- a/src/GraphModel/Node.cpp
+++ b/src/GraphModel/Node.cpp
@@ -5,5 +5,9 @@ namespace GraphC::GraphModel {
 Node::Node(id_t _id, std::string _title) 
     : id(_id), title(_title)
 {}
+    
+const RBTree<id_t, Attribute*>& Node::getAttributes() const {
+    return attributes;
+}
 
 }
diff --git a/src/RBTree.hpp b/src/RBTree.hpp
index 76dde77..f46c2e1 100644
--- a/src/RBTree.hpp
+++ b/src/RBTree.hpp
@@ -2,7 +2,7 @@
 
 #include "../../dependencies/kerep/src/base/base.h"
 #include <map>
-#include <memory>
+#include <sstream>
 
 // typedef char* TKey;
 // typedef char* TVal;
@@ -69,57 +69,6 @@ class RBTree {
         }
     };
 
-    template<typename TIteratorValue>
-    struct TreeIterator : std::iterator<std::bidirectional_iterator_tag, TIteratorValue> {
-        Node* n;
-
-        TreeIterator(TreeIterator const& src){
-            n = src.n;
-        }
-
-        TreeIterator(Node* ptr){
-            n = ptr;
-        }
-
-        bool operator!=(TreeIterator const& other) const {
-            return n == other.n;
-        }
-
-        bool operator==(TreeIterator const& other) const {
-            return n == other.n;
-        }
-
-        reference operator*() const {
-            if(n == nullptr)
-                throw "RBTree::TreeIterator::operator*() error: n == nullptr";
-            return *((pointer)(void*)n);
-        }
-
-        TreeIterator& operator++() {
-            if(n == nullptr)
-                return *this;
-            Node* prev_n = nullptr;
-            while(n->parent != nullptr && (n->right == nullptr || n->right == prev_n)){
-                prev_n = n;
-                n = n->parent;
-            }
-            n = n->right;
-            return *this;
-        }
-
-        TreeIterator& operator--() {
-            if(n == nullptr)
-                return *this;
-            Node* prev_n = nullptr;
-            while(n->parent != nullptr && (n->left == nullptr || n->left == prev_n)){
-                prev_n = n;
-                n = n->parent;
-            }
-            n = n->left;
-            return *this;
-        }
-    };
-
 
     Node* root = nullptr;
 
@@ -133,7 +82,7 @@ class RBTree {
                 n = n->left;
             else if(key > n->key) 
                 n = n->right;
-            else return nullptr; // key == n->key
+            else return n->parent; // key == n->key
         }
         return parent;
     }
@@ -147,8 +96,8 @@ class RBTree {
             if(x == x->parent->left)
                 x->parent->left = y;
             else x->parent->right = y;
-            // TODO: maybe should set root to y?
         }
+        else root = y;
         // 3. move y.left to x.right if it exists
         x->right = y->left;
         if (x->right != nullptr)
@@ -168,6 +117,7 @@ class RBTree {
                 x->parent->left = y;
             else x->parent->right = y;
         }
+        else root = y;
         // 3. move y.right to x.left if it exists
         x->left = y->right;
         if (x->left != nullptr)
@@ -178,12 +128,13 @@ class RBTree {
     }
 
     void transplantNode(Node* old, Node* neww){
-        neww->parent = old->parent;
         if(old->parent == nullptr)
             root = neww;
         else if(old->parent->left == old)
             old->parent->left = neww;
         else old->parent->right = neww;
+        if(neww != nullptr)
+            neww->parent = old->parent;
     }
 
     void fixupInsertion(Node* n){
@@ -297,6 +248,48 @@ class RBTree {
     }
 
 
+    template<typename TIteratorValue>
+    struct TreeIterator : std::iterator<std::bidirectional_iterator_tag, TIteratorValue> {
+        Node* n;
+
+        TreeIterator(TreeIterator const& src){
+            n = src.n;
+        }
+
+        TreeIterator(Node* ptr){
+            n = ptr;
+        }
+
+        bool operator!=(TreeIterator const& other) const {
+            return n != other.n;
+        }
+
+        bool operator==(TreeIterator const& other) const {
+            return n == other.n;
+        }
+
+        TIteratorValue& operator*() const {
+            if(n == nullptr)
+                throw "RBTree::TreeIterator::operator*() error: n == nullptr";
+            return *((TIteratorValue*)(void*)n);
+        }
+
+        void operator++() {
+            if(n == nullptr)
+                return;
+            if(n->right)
+                n = n->right->getMinChild();
+            else {
+                Node* p = n->parent;
+                while(p != nullptr && n == p->right){
+                    n = p;
+                    p = p->parent;
+                }
+                n = p;
+            }
+        }
+    };
+
 public:
     using iterator = TreeIterator<std::pair<const TKey, TVal>>;
     using const_iterator = TreeIterator<std::pair<const TKey, const TVal>>;
@@ -425,8 +418,10 @@ public:
         if(!resultPtr)
             return false;
         Node* parent = findParentForKey(key);
-        Node* n;
-        if(key < parent->key)
+        Node* n = nullptr;
+        if(parent == nullptr)
+            n = root;
+        else if(key < parent->key)
             n = parent->left;
         else n = parent->right;
         // if there is no node with the given key
@@ -442,8 +437,10 @@ public:
 
     bool tryDelete(TKey key){
         Node* parent = findParentForKey(key);
-        Node* n;
-        if(key < parent->key)
+        Node* n = nullptr;
+        if(parent == nullptr)
+            n = root;
+        else if(key < parent->key)
             n = parent->left;
         else n = parent->right;
         // key not found
@@ -453,12 +450,12 @@ public:
         
         if(n->left == nullptr){
             transplantNode(n, n->right);
-            if(n->color == Color::Black)
+            if(n->color == Color::Black && n->right != nullptr)
                 fixupDeletion(n->right);
         }
         else if(n->right == nullptr){
             transplantNode(n, n->left);
-            if(n->color == Color::Black)
+            if(n->color == Color::Black && n->left != nullptr)
                 fixupDeletion(n->left);
         }
         else {
@@ -477,6 +474,7 @@ public:
         }
     
         delete n;
+        return true;
     }
 
 
@@ -499,8 +497,37 @@ public:
     }
 
     const_iterator end() const {
-        if(root == nullptr)
             return const_iterator(nullptr);
-        return const_iterator(root->getMaxChild());
+    }
+
+    void _generateGraphVizCodeForChildren(std::stringstream& ss, Node* n) const {
+        if(!n)
+            return;
+        if(n->color == Color::Red)
+            ss<<"    \""<<n->key<<"\" [color=red]\n";
+        if(n->left){
+            ss<<"    \""<<n->key<<"\" -> \""<<n->left->key<<"\" [side=L]\n";
+            _generateGraphVizCodeForChildren(ss, n->left);
+        }
+        else ss<<"    \""<<n->key<<"\" -> \"null\" [side=L]\n";
+        if(n->right){
+            ss<<"    \""<<n->key<<"\" -> \""<<n->right->key<<"\" [side=R]\n";
+            _generateGraphVizCodeForChildren(ss, n->right);
+        }
+        else ss<<"    \""<<n->key<<"\" -> \"null\" [side=R]\n";
+    }
+
+    std::string generateGraphVizCode() const {
+        std::stringstream ss;
+        ss<<"digraph {\n"
+            "    node [style=filled,color=gray];\n";
+        if(root == nullptr)
+            ss<<"    \"null\"\n";
+        else {
+            ss<<"    \"null-parent\" -> \""<<root->key<<"\"\n";
+            _generateGraphVizCodeForChildren(ss, root);
+        }
+        ss<<"}";
+        return ss.str();
     }
 };
diff --git a/src/UsefulException.hpp b/src/UsefulException.hpp
index ae6f668..de53447 100644
--- a/src/UsefulException.hpp
+++ b/src/UsefulException.hpp
@@ -18,10 +18,4 @@ public:
     virtual char const* what() const noexcept;
 };
 
-#if DEBUG == 1
-/// Use this macro to find bugs in debug build. Release build could be compiled without asserts. Define DEBUG=1 to enable assert compilation.
-    #define assert(EXPR, ERRMSG) if(!EXPR) throw UsefulException(ERRMSG);
-#else
-/// Use this macro to find bugs in debug build. Release build could be compiled without asserts. Define DEBUG=1 to enable assert compilation.
-    #define assert(EXPR, ERRMSG) EXPR
-#endif
+#define useful_assert(EXPR, ERRMSG) if(!EXPR) throw UsefulException(ERRMSG);
diff --git a/src/gui/NodeEditor.cpp b/src/gui/NodeEditor.cpp
index fa0bb5c..055f68b 100644
--- a/src/gui/NodeEditor.cpp
+++ b/src/gui/NodeEditor.cpp
@@ -4,16 +4,15 @@
 
 namespace GraphC::gui {
 
-void drawNode(GraphModel::Node& node){
+void NodeEditor::drawNode(const GraphModel::Node& node){
     ImNodes::BeginNode(node.id);
         ImNodes::BeginNodeTitleBar();
             ImGui::TextUnformatted(node.title.c_str());
         ImNodes::EndNodeTitleBar();
 
-        for(GraphModel::Attribute& a : node.attributes)
-        {
-            switch (a.type)
-            {
+        for(auto& a_p : node.getAttributes()){
+            auto&& a = *a_p.second;
+            switch (a.type){
                 case GraphModel::Attribute::Type::Input:
                     ImNodes::BeginInputAttribute(a.id);
                         ImGui::Text("%s", a.title.c_str());
@@ -35,19 +34,72 @@ void drawNode(GraphModel::Node& node){
                     break;
             }
         }
+
+        const char* items[]={
+            "static","input", "output"
+        };
+        static int selected_item_i = 0;
+        if(ImGui::Button("add attribute"))
+            ImGui::OpenPopup("new_attribute_popup");
+        
+        if(ImGui::BeginPopup("new_attribute_popup")){
+            ImGui::SeparatorText("New attribute properties");
+
+            static char buf[256];
+            ImGui::InputText("label", buf, sizeof(buf));
+            
+            if(ImGui::Button("select type"))
+                ImGui::OpenPopup("select_type_popup");
+            ImGui::SameLine();
+            ImGui::TextUnformatted(items[selected_item_i]);
+
+            if(ImGui::BeginPopup("select_type_popup")){
+                for (int i = 0; i < IM_ARRAYSIZE(items); i++)
+                    if (ImGui::Selectable(items[i]))
+                        selected_item_i = i;
+                ImGui::EndPopup();
+            }
+            
+            if(ImGui::Button("Create attribute")){
+                graph.createAttribute(GraphModel::Attribute(
+                    graph.id_gen.getNext(), 
+                    const_cast<GraphModel::Node*>(&node), 
+                    (GraphModel::Attribute::Type)selected_item_i,
+                    std::string(buf)));
+
+                std::cout<<"ATTRIBUTES:\n";
+                std::cout<<graph.getAttributes().generateGraphVizCode()<<std::endl;
+
+                ImGui::CloseCurrentPopup();
+                buf[0] = 0;
+                selected_item_i = 0;
+            }
+
+            ImGui::EndPopup();
+        }
     ImNodes::EndNode();
 }
 
 
-GraphModel::Node CreateExampleNode(GraphModel::id_t* next_id, std::string title){
-    GraphModel::Node a = GraphModel::Node((*next_id)++, title);
-    a.attributes.push_back(GraphModel::Attribute((*next_id)++, &a, GraphModel::Attribute::Type::Input, "In"));
-    a.attributes.push_back(GraphModel::Attribute((*next_id)++, &a, GraphModel::Attribute::Type::Output, "Out"));
-    a.attributes.push_back(GraphModel::Attribute((*next_id)++, &a, GraphModel::Attribute::Type::Static, "Static"));
-    return a;
+GraphModel::Node* NodeEditor::CreateExampleNode(std::string title){
+    GraphModel::Node* n = graph.createNode(GraphModel::Node(graph.id_gen.getNext(), title));
+    graph.createAttribute(GraphModel::Attribute(graph.id_gen.getNext(), n, GraphModel::Attribute::Type::Input, "In"));
+    graph.createAttribute(GraphModel::Attribute(graph.id_gen.getNext(), n, GraphModel::Attribute::Type::Output, "Out"));
+    graph.createAttribute(GraphModel::Attribute(graph.id_gen.getNext(), n, GraphModel::Attribute::Type::Static, "Static"));
+    return n;
 }
 
-NodeEditor::NodeEditor(std::string _title) : title(_title) {
+NodeEditor::NodeEditor(std::string _title) 
+    : title(_title) 
+{
+    // CreateExampleNode("Node A");
+    // CreateExampleNode("Node B");
+    // CreateExampleNode("Node C");
+    // CreateExampleNode("Node D");
+    std::cout<<"NODES:\n";
+    std::cout<<graph.getNodes().generateGraphVizCode()<<std::endl;
+    std::cout<<"ATTRIBUTES:\n";
+    std::cout<<graph.getAttributes().generateGraphVizCode()<<std::endl;
 }
 
 void NodeEditor::show(){
@@ -65,37 +117,56 @@ void NodeEditor::draw(){
     ImGui::Begin(title.c_str(), &editor_open);
 
         ImGui::SetWindowSizeMin(300,300);
+        
+        if(ImGui::Button("create node")){
+            ImGui::OpenPopup("create_node_popup");
+        }
+        static char buf[256];
+        if(ImGui::BeginPopup("create_node_popup")){
+            ImGui::SeparatorText("New node properties");
+            ImGui::InputText("label", buf, sizeof(buf));
+            if(ImGui::Button("create node")){
+                graph.createNode(GraphModel::Node(graph.id_gen.getNext(), buf));
+
+                std::cout<<"NODES:\n";
+                std::cout<<graph.getNodes().generateGraphVizCode()<<std::endl;
+
+                buf[0] = 0;
+                ImGui::CloseCurrentPopup();
+            }
+            ImGui::EndPopup();
+        }
+        
         ImNodes::BeginNodeEditor();
             // draw nodes
-            for(auto&& p : graph->getNodes()){
-                drawNode(p.second);
+            for(auto& n_p : graph.getNodes()){
+                drawNode(n_p.second);
             }
             // draw edges
-            const auto& edges = graph->getEdges();
-            edges.empl = GraphModel::Edge();
-            for(auto&& p : edges){
+            for(auto& p : graph.getEdges()){
                 ImNodes::Link(p.second.id, p.second.to_attr_id, p.second.from_attr_id);
             }
+
         ImNodes::EndNodeEditor();
 
         // handle edge creation
-        GraphModel::id_t to_attr_id;
-        GraphModel::id_t from_attr_id;
+        GraphModel::id_t from_attr_id, to_attr_id;
         if (ImNodes::IsLinkCreated(&from_attr_id, &to_attr_id))
         {
-            graph->createEdge(graph->getEdge(from_attr_id), graph->getEdge(to_attr_id));
+            if(!graph.tryCreateEdge(from_attr_id, to_attr_id, nullptr))
+                throw UsefulException(format("can't create edge from attribute %i to attribute %i", from_attr_id, to_attr_id));
+            std::cout<<"EDGES:\n";
+            std::cout<<graph.getEdges().generateGraphVizCode()<<std::endl;
         }
     
         // handle edge destruction
         GraphModel::id_t edge_id;
         if (ImNodes::IsLinkDestroyed(&edge_id))
         {
-            auto iter = std::find_if(edges.begin(), edges.end(), 
-                [edge_id](const GraphModel::Edge& edge) -> bool {
-                    return edge.id == edge_id;
-                });
-            assert(iter != edges.end());
-            edges.erase(iter);
+            if(!graph.tryDeleteEdge(edge_id))
+                throw UsefulException(format("can't delete edge with id %i", edge_id));
+            std::cout<<"EDGES:\n";
+            std::cout<<graph.getEdges().generateGraphVizCode()<<std::endl;
         }
 
     ImGui::End();
diff --git a/src/gui/NodeEditor.hpp b/src/gui/NodeEditor.hpp
index d6842c1..1233694 100644
--- a/src/gui/NodeEditor.hpp
+++ b/src/gui/NodeEditor.hpp
@@ -10,8 +10,11 @@ class NodeEditor {
     std::string title=nullptr;
     bool editor_open=false;
     ImNodesContext* editor_context=nullptr;
-    std::shared_ptr<GraphModel::Graph> graph;
+    GraphModel::Graph graph;
     
+    void drawNode(const GraphModel::Node& node);
+    GraphModel::Node* CreateExampleNode(std::string title);
+
 public:
     NodeEditor(std::string _title);
 
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 546f69b..bb554d5 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -75,8 +75,8 @@ void GUI::init(const char* window_title){
     ImNodes::CreateContext();
     ImNodes::StyleColorsDark();
     ImNodes::PushAttributeFlag(ImNodesAttributeFlags_EnableLinkDetachWithDragClick);
-    node_editor=NodeEditor("node editor");
-    node_editor.show();
+    node_editor = new NodeEditor("node editor");
+    node_editor->show();
 }
 
 // Wait, poll and handle events (inputs, window resize, etc.)
@@ -118,7 +118,7 @@ void GUI::draw_frame(){
     // Draw UI
     draw_bg_window();
     draw_debug_window(io, &main_loop_wait_for_input);
-    node_editor.draw();
+    node_editor->draw();
 
     // Rendering
     ImGui::Render();
diff --git a/src/gui/gui.hpp b/src/gui/gui.hpp
index 9e1c4a2..1b380b2 100644
--- a/src/gui/gui.hpp
+++ b/src/gui/gui.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
-#include "../../dependencies/kerep/src/base/base.h"
+#include "../../dependencies/kerep/src/base/std.h"
+#include "../../dependencies/kerep/src/kprint/kprintf.h"
 #include "../../dependencies/SDL2/include/SDL.h"
 #include "../../dependencies/SDL2/include/SDL_opengl.h"
 #include "../../dependencies/imgui/imgui.h"
@@ -9,6 +10,8 @@
 #include "imgui_extensions.hpp"
 #include "fonts.hpp"
 #include "exceptions.hpp"
+#include <iostream>
+#include <string>
 
 /// converts hex color to float vector
 #define RGBAHexToF(R8,G8,B8,A8) ImVec4(((u8)35)/255.0f, ((u8)35)/255.0f, ((u8)50)/255.0f, ((u8)255)/255.0f)
@@ -33,7 +36,7 @@ private:
     bool show_metrics_window = false;
     SDL_Window* sdl_window;
     SDL_GLContext gl_context;
-    NodeEditor node_editor = NodeEditor("new editor");
+    NodeEditor* node_editor = nullptr;
 
 public:
     void init(const char* window_title);