diff --git a/package.json b/package.json
index 1c6c16e..df1d9ee 100644
--- a/package.json
+++ b/package.json
@@ -5,7 +5,7 @@
   "main": "dist/index.js",
   "scripts": {
     "build": "tsc",
-    "start": "node dist/index.js",
+    "start": "tsc; node dist/index.js",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "repository": {
diff --git a/src/types.ts b/src/types.ts
index e69de29..1d1cfff 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -0,0 +1,34 @@
+namespace Carpool {
+	interface Group {
+		id: string;
+		member_ids: string[];
+	}
+
+	interface User {
+		id: string;
+		first_name: string;
+		last_name: string;
+	}
+
+	interface Comment {
+		id: string;
+		body: string;
+		author_id: string;
+	}
+
+	type Status = "pending" | "cancelled" | "completed" | "interrupted";
+
+	interface Post {
+		id: string;
+		title: string;
+		description: string;
+		participant_ids: string[];
+		driver_id: string;
+		create_time: string;
+		update_time: string;
+		comments: Comment[];
+		group_id: string;
+		status: Status;
+		capacity: number;
+	}
+}
\ No newline at end of file
diff --git a/tsconfig.json b/tsconfig.json
index 3e0d3c9..2e3b371 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,7 +1,8 @@
 {
 	"compilerOptions": {
-		"outDir": "dist/"
+		"outDir": "dist/",
 	},
+	"files": ["src/types.ts"],
 	"include": ["src/"],
 	"exclude": ["node_modules/"],
 }
\ No newline at end of file