better-auth/docs/app/api/search/route.ts

import { getPages } from "@/app/source";
import { createSearchAPI } from "fumadocs-core/search/server";

export const { GET } = createSearchAPI("advanced", {
	indexes: getPages().map((page) => ({
		title: page.data.title,
		structuredData: page.data.exports.structuredData,
		id: page.url,
		url: page.url,
	})),
});