diff --git a/src/core.ts b/src/core.ts
index 8e03bbe5..aaa43efc 100644
--- a/src/core.ts
+++ b/src/core.ts
@@ -5,8 +5,10 @@ import { glob } from "glob";
 import { Config, configSchema } from "./config.js";
 import { Page } from "playwright";
 import { isWithinTokenLimit } from "gpt-tokenizer";
+import { PathLike } from "fs";
 
 let pageCounter = 0;
+let crawler: PlaywrightCrawler;
 
 export function getPageHtml(page: Page, selector = "body") {
   return page.evaluate((selector) => {
@@ -52,7 +54,7 @@ export async function crawl(config: Config) {
   if (process.env.NO_CRAWL !== "true") {
     // PlaywrightCrawler crawls the web using a headless
     // browser controlled by the Playwright library.
-    const crawler = new PlaywrightCrawler({
+    crawler = new PlaywrightCrawler({
       // Use the requestHandler to process each of the crawled pages.
       async requestHandler({ request, page, enqueueLinks, log, pushData }) {
         if (config.cookie) {
@@ -143,6 +145,7 @@ export async function crawl(config: Config) {
 }
 
 export async function write(config: Config) {
+  let nextFileNameString: PathLike = "";
   const jsonFiles = await glob("storage/datasets/default/*.json", {
     absolute: true,
   });
@@ -163,8 +166,14 @@ export async function write(config: Config) {
     `${config.outputFileName.replace(/\.json$/, "")}-${fileCounter}.json`;
 
   const writeBatchToFile = async (): Promise<void> => {
-    await writeFile(nextFileName(), JSON.stringify(currentResults, null, 2));
-    console.log(`Wrote ${currentResults.length} items to ${nextFileName()}`);
+    nextFileNameString = nextFileName();
+    await writeFile(
+      nextFileNameString,
+      JSON.stringify(currentResults, null, 2),
+    );
+    console.log(
+      `Wrote ${currentResults.length} items to ${nextFileNameString}`,
+    );
     currentResults = [];
     currentSize = 0;
     fileCounter++;
@@ -213,4 +222,31 @@ export async function write(config: Config) {
   if (currentResults.length > 0) {
     await writeBatchToFile();
   }
+
+  return nextFileNameString;
 }
+
+class GPTCrawlerCore {
+  config: Config;
+
+  constructor(config: Config) {
+    this.config = config;
+  }
+
+  async crawl() {
+    await crawl(this.config);
+  }
+
+  async write(): Promise<PathLike> {
+    // we need to wait for the file path as the path can change
+    return new Promise((resolve, reject) => {
+      write(this.config)
+        .then((outputFilePath) => {
+          resolve(outputFilePath);
+        })
+        .catch(reject);
+    });
+  }
+}
+
+export default GPTCrawlerCore;
diff --git a/src/server.ts b/src/server.ts
index bf3ff510..50497a99 100644
--- a/src/server.ts
+++ b/src/server.ts
@@ -1,12 +1,13 @@
 import express from "express";
 import cors from "cors";
 import { readFile } from "fs/promises";
-import { crawl, write } from "./core.js";
 import { Config, configSchema } from "./config.js";
 import { configDotenv } from "dotenv";
 import swaggerUi from "swagger-ui-express";
 // @ts-ignore
 import swaggerDocument from "../swagger-output.json" assert { type: "json" };
+import GPTCrawlerCore from "./core.js";
+import { PathLike } from "fs";
 
 configDotenv();
 
@@ -23,12 +24,10 @@ app.post("/crawl", async (req, res) => {
   const config: Config = req.body;
   try {
     const validatedConfig = configSchema.parse(config);
-    await crawl(validatedConfig);
-    await write(validatedConfig);
-    const outputFileContent = await readFile(
-      validatedConfig.outputFileName,
-      "utf-8",
-    );
+    const crawler = new GPTCrawlerCore(validatedConfig);
+    await crawler.crawl();
+    const outputFileName: PathLike = await crawler.write();
+    const outputFileContent = await readFile(outputFileName, "utf-8");
     res.contentType("application/json");
     return res.send(outputFileContent);
   } catch (error) {
diff --git a/tsconfig.json b/tsconfig.json
index ddf6ba3b..a4193efa 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -4,6 +4,7 @@
     "module": "ES2022",
     "target": "ES2022",
     "outDir": "dist",
+    "moduleResolution": "node",
     "resolveJsonModule": true,
     "noUnusedLocals": false,
     "skipLibCheck": true,