diff --git a/src/services/reputation/graph.interface.ts b/src/services/reputation/graph.interface.ts
new file mode 100644
index 0000000..a0716d6
--- /dev/null
+++ b/src/services/reputation/graph.interface.ts
@@ -0,0 +1,27 @@
+
+export interface Graph {
+    vertices: Map<string, Vertex>;
+    edges: Map<string, Edge>;
+    getAllVertices(): Vertex[];
+    getVertex(id: string): Vertex;
+    addVertex(vertex: Vertex): void;
+    deleteVertex(vertex: string | Vertex): void;
+    getAllEdges(): Edge[];
+    getEdge(id: string): Edge;
+    addEdge(edge: Edge): void;
+    deleteEdge(edge: string | Edge): void;
+}
+
+export interface Vertex {
+    id: string;
+    edges: Edge[];
+    data: string;
+}
+
+export interface Edge {
+    id: string;
+    directional: boolean;
+    parentVertex: Vertex;
+    childVertex: Vertex;
+    getAdjacent(vertex: Vertex): Vertex;
+}
\ No newline at end of file