diff --git a/compiler/arch.ts b/compiler/arch.ts
index 77a73d7..203a1f1 100644
--- a/compiler/arch.ts
+++ b/compiler/arch.ts
@@ -1,5 +1,17 @@
-export type Ins = Ops | number;
+import { Pos } from "./Token.ts";
+
+export type Output = {
+    program: Program;
+    sourceMap: SourceMapping[];
+};
+
 export type Program = Ins[];
+export type Ins = Ops | number;
+
+export type SourceMapping = {
+    bytecodeOffset: number;
+    pos: Pos;
+};
 
 // NOTICE: keep up to date with runtime/arch.hpp