add version endpoint

src/pages/api/version.ts

@@ -0,0 +1,17 @@
+import { NextApiRequest, NextApiResponse } from 'next';
+import { ok, methodNotAllowed } from 'next-basics';
+import { CURRENT_VERSION } from 'lib/constants';
+
+export interface VersionResponse {
+  version: string;
+}
+
+export default async (req: NextApiRequest, res: NextApiResponse<VersionResponse>) => {
+  if (req.method === 'GET') {
+    return ok(res, {
+      version: CURRENT_VERSION,
+    });
+  }
+
+  return methodNotAllowed(res);
+};