Stagehand migration v2 -> v3 by AnSingh1 · Pull Request #6 · browserbase/brainrot

AnSingh1 · 2026-01-09T17:59:38Z

This pull request refactors the app/api/chat/route.ts API handler to stagehand v3 (originally stagehand v2) for meme generation to improve reliability, error handling, and integration with the Stagehand automation library. It also updates dependencies and configuration to support these changes. The main improvements include switching to the latest @browserbasehq/stagehand package, restructuring the session and page management logic, and enhancing error reporting for easier debugging.

Also updates from depreciated sonnet3.5 -> sonnet4.5

API handler improvements:

Refactored session and page management: The handler now initializes Stagehand with a new configuration object, connects to an existing Browserbase session if available, and manages pages directly from the stagehand.context.pages() array for better reliability.
Replaced direct page.act and page.extract calls with stagehand.act and stagehand.extract methods, aligning with the updated Stagehand API and ensuring consistent automation steps.
Improved error handling: Added detailed error logging, including stack traces and serialized error details, to make debugging failures much easier. Error responses now include the error message for client visibility.
Cleaned up resource management: Removed redundant page closing logic and ensured stagehand.close() is called reliably in the finally block.

Dependency and configuration updates:

Updated @browserbasehq/stagehand to version ^3.0.7 and @browserbasehq/sdk to ^2.6.0 in package.json to support new API features and stability improvements.
Added serverExternalPackages to next.config.ts to ensure required packages are bundled for server-side execution.

Note:

Debugging connection was closed. Reason: WebSocket disconnected. Reconnect when ready by reopening DevTools error STILL persists.

vercel · 2026-01-09T17:59:42Z

@AnSingh1 is attempting to deploy a commit to the browserbase Team on Vercel.

A member of the Team first needs to authorize it.

Kylejeong2

left some comments about use of "any" typing & some other code quality things. after fixing I'll deploy a preview to vercel to test

Kylejeong2 · 2026-01-11T05:13:02Z

app/api/chat/route.ts

+      console.log("Connecting to existing Browserbase session:", sessionId);
+    }
+
+    console.log("Stagehand config:", {


remove log we don't need

Kylejeong2 · 2026-01-11T05:13:19Z

app/api/chat/route.ts

+      apiKey: process.env.BROWSERBASE_API_KEY,
+      projectId: process.env.BROWSERBASE_PROJECT_ID,
+      domSettleTimeout: 30000,
+      model: "anthropic/claude-3-5-sonnet-20241022",


i think this model is deprecated can upgrade to 4.5 sonnet

Kylejeong2 · 2026-01-11T05:13:32Z

app/api/chat/route.ts

-    stagehand = new Stagehand(StagehandConfig);
+    const stagehandConfig: any = {
+      env:
+        process.env.BROWSERBASE_API_KEY && process.env.BROWSERBASE_PROJECT_ID


set to "BROWSERBASE" always, this is not meant to run locally

ignore the original impl. being like that

Kylejeong2 · 2026-01-11T05:14:17Z

app/api/chat/route.ts


    console.log("Initializing Stagehand instance...");
-    await stagehand.init();
+    console.log("Available pages in context:", stagehand.context.pages().length);


dont need this log

Kylejeong2 · 2026-01-11T05:15:09Z

app/api/chat/route.ts

+
+    if (pages.length === 0) {
+      throw new Error("No pages available in context after init");
+    }


we only need a single page object so instead of this code we only need one line

const page = stagehand.context.pages()[0];

Kylejeong2 · 2026-01-11T05:15:49Z

app/api/chat/route.ts

-      const page = await stagehand.page;
+
+      // Wait a bit for the session to be fully ready
+      await new Promise(resolve => setTimeout(resolve, 2000));


we shouldn't need this either, was it not working previously with no extra timeout?

Kylejeong2 · 2026-01-11T05:16:40Z

app/api/chat/route.ts

-        templateInfo = await page.act({
-          action: `Look at the meme templates on the page. Find a template that would work well with the message "${message}". Click on "Add Caption" for the template you think is the best match.`,
-        });
+        console.log("About to call stagehand.act()...");


can remove log

Kylejeong2 · 2026-01-11T05:18:32Z

app/api/chat/route.ts


-        console.log("Template name:", templateInfo.name);
+        templateInfo = extractedData;
+        console.log("Template name:", (templateInfo as any).name);


we should not use any here, we can use object destructuring above here to get { name } from the stagehand extract call and then log just the name instead

Kylejeong2 · 2026-01-11T05:18:41Z

app/api/chat/route.ts

      } catch (error) {
-        console.log(`Error finding template in ${source.description}:`, error);
+        console.error(`Error finding template in ${source.description}:`, error);
+        console.error("Full error stack:", (error as any).stack);


same as above (don't use any)

Kylejeong2 · 2026-01-11T05:19:07Z

next.config.ts

 import type { NextConfig } from "next";

 const nextConfig: NextConfig = {
+  serverExternalPackages: [


is there a reason we need to do this ?

removing breaks Stagehand + Pino in App Router routes

Next.js bundles thread-stream/pino (Stagehand dependencies), which corrupts worker paths

leads to error code: ERR_WORKER_PATH

more: https://nextjs.org/docs/app/api-reference/next-config-js/serverExternalPackages

AnSingh1 added 2 commits January 9, 2026 12:22

migrate to stagehandv3

01771b7

added debugging

ba47129

Kylejeong2 requested changes Jan 11, 2026

View reviewed changes

AnSingh1 added 2 commits January 11, 2026 00:39

update to sonnet 4.5

0a6f21b

fix pino worker path corruption

546270d

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AnSingh1 commented Jan 9, 2026 •

edited

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