diff --git a/lib/Graphable.ts b/lib/Graphable.ts
new file mode 100644
index 0000000..b6b3442
--- /dev/null
+++ b/lib/Graphable.ts
@@ -0,0 +1,5 @@
+import { Graph } from './Graph';
+
+export interface Graphable {
+  to_graph(g: Graph): void;
+}
diff --git a/lib/index.ts b/lib/index.ts
index e029ed0..279ac57 100644
--- a/lib/index.ts
+++ b/lib/index.ts
@@ -5,3 +5,4 @@ export { Edge } from './Edge';
 export { Color } from './Color';
 export { EdgeStyles, NodeStyles, GraphStyles } from './Styles';
 export { GraphLayouts } from './GraphLayouts';
+export { Graphable } from './Graphable';