Advance configuration return undefined

[Bikiin]

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Environment Information

Please provide the following information to help us reproduce and resolve your issue:

Stagehand:

• Language/SDK: [TypeScript, Python, MCP…]
• Stagehand version: [e.g., 3.0.1]

AI Provider:

• Provider: N/A (not used in this repro)
• Model: N/A

Issue Description

`stagehand.init()` resolves to `undefined` when using env "BROWSERBASE", even though the session starts successfully.
The Stagehand logs print `sessionUrl`, `debugUrl`, and `sessionId`, but the variable that awaits `init()` is `undefined`.

Steps to Reproduce

1. Create a Stagehand instance with the example https://docs.stagehand.dev/v3/configuration/browser#advanced-configuration.
2. Call const result = await stagehand.init();
3. Log the value: console.log("result" ,result); → it prints undefined, while Stagehand logs show the session details.

Minimal Reproduction Code

// Your minimal reproduction code here
import { Stagehand } from '@browserbase/stagehand';

const stagehand = new Stagehand({
  // IMPORTANT: include your stagehand config
  env: 'BROWSERBASE',
  apiKey: 'REDACTED',
  projectId: 'REDACTED',
  browserbaseSessionCreateParams: {
    projectId: 'REDACTED',
    proxies: false,
    region: 'us-west-2',
    timeout: 3600,
    keepAlive: true,
    browserSettings: {
      advancedStealth: false,
      blockAds: true,
      solveCaptchas: true,
      recordSession: false,
      viewport: { width: 1920, height: 1080 },
    },
  },
  userMetadata: {
    userId: 'automation-user-123',
    environment: 'production',
  },
});

// Steps that reproduce the issue
(async () => {
  const config = await stagehand.init();
  console.log('CONFIG', config); // => undefined (unexpected)
})();

Error Messages / Log trace

[2025-11-05 22:18:43.008 +0000] INFO: Using Browserbase credentials
category: "init"
[2025-11-05 22:18:43.008 +0000] INFO: Starting browserbase session
category: "init"
[2025-11-05 22:18:43.009 +0000] INFO: Creating new browserbase session...
category: "init"

CONFIG undefined

[2025-11-05 22:18:48.999 +0000] INFO: Browserbase session started
category: "init"
sessionUrl: "https://www.browserbase.com/sessions/<redacted>"
debugUrl: "https://www.browserbase.com/devtools/inspector.html?wss=connect.browserbase.com/debug/<redacted>/devtools/page/<redacted>?debug=true"
sessionId: "9c3b72bc-a519-4aa6-b849-a364a0723684"

Screenshots / Videos

Related Issues

Are there any related issues or PRs?

• Related to: #[issue number]
• Duplicate of: #[issue number]
• Blocks: #[issue number]