diff --git a/apps/api/src/errors/AppError.ts b/apps/api/src/errors/AppError.ts
index 6611b9b..4677d9f 100644
--- a/apps/api/src/errors/AppError.ts
+++ b/apps/api/src/errors/AppError.ts
@@ -19,3 +19,9 @@ export class NotFoundError extends AppError {
     super(message, 404);
   }
 }
+
+export class ConflictError extends AppError {
+  constructor(message: string) {
+    super(message, 409);
+  }
+}
diff --git a/apps/api/src/middleware/authMiddleware.ts b/apps/api/src/middleware/authMiddleware.ts
index da18d01..744c5e4 100644
--- a/apps/api/src/middleware/authMiddleware.ts
+++ b/apps/api/src/middleware/authMiddleware.ts
@@ -16,5 +16,7 @@ export const requireAuth = async (
     return;
   }
 
+  req.session = session;
+
   next();
 };
diff --git a/apps/api/src/types/express.d.ts b/apps/api/src/types/express.d.ts
new file mode 100644
index 0000000..914a2fd
--- /dev/null
+++ b/apps/api/src/types/express.d.ts
@@ -0,0 +1,11 @@
+import type { Session, User } from "better-auth";
+
+declare global {
+  namespace Express {
+    interface Request {
+      session?: { session: Session; user: User };
+    }
+  }
+}
+
+export {};