diff --git a/include/graph.h b/include/graph.h
index ac244c9..d242263 100644
--- a/include/graph.h
+++ b/include/graph.h
@@ -9,6 +9,8 @@ typedef struct Edge Edge;
 
 typedef enum {
     GRAPH_OK,
+    GRAPH_BAD_ALLOC,
+    GRAPH_NOT_FOUND,
 } GraphErr ;
 
 typedef enum {
@@ -16,5 +18,18 @@ typedef enum {
     GRAPH_UNDIRECTED,
 } GraphType;
 
+Graph *graph_create(GraphType type);
+GraphErr graph_destroy(Graph *graph);
+
+GraphErr graph_add_vertex(Graph *graph);
+
+GraphErr graph_connect_vertex(
+    Graph *graph,
+    size_t node1,
+    size_t node2,
+    size_t weight);
+
+GraphErr graph_vertex_count(size_t *out);
+GraphErr graph_get_vertex(Graph *graph, size_t index, Vertex *out);
 
 #endif
diff --git a/src/graph.c b/src/graph.c
index cf53a7e..6a2d40c 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -4,19 +4,15 @@
 #include <stdint.h>
 
 struct Vertex {
-    void *data;
     ArrayList *edges;
 };
 
 struct Edge {
-    size_t *to;
-    intmax_t weight;
+    size_t to;
+    size_t weight;
 };
 
 struct Graph {
     ArrayList *vertices;
     GraphType type;
-    
-    int (*cmp)(const void*, const void*);
-    void (*free_data)(void*);
 };