`googleGenAIIntegration` wraps multi-element array responses in nested arrays

[arik-mesh]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Sentry Saas (sentry.io)

Which SDK are you using?

@sentry/aws-serverless

SDK Version

@sentry/aws-serverless@10.33.0

Framework Version

No response

Link to Sentry event

No response

Reproduction Example/SDK Setup

import * as Sentry from '@sentry/aws-serverless';

Sentry.init({
dsn: process.env.SENTRY_DSN,
environment: process.env.environment,
integrations: [
Sentry.captureConsoleIntegration({ levels: ['error'] }),
Sentry.googleGenAIIntegration({
recordInputs: true,
recordOutputs: true
})
],
tracesSampleRate: 1.0,
sendDefaultPii: true,
});

Steps to Reproduce

1. Configure googleGenAIIntegration with @sentry/aws-serverless@10.33.0
2. Use @google/genai@1.15.0 to call the Gemini API
3. Send a prompt that requests multiple items (e.g., "Extract all line items from this receipt")
4. The API correctly returns a multi-element array, but the response is mutated

Expected Result

When the Google GenAI SDK returns a multi-element array:

[
  {"description": "Item A", "amount": 100},
  {"description": "Item B", "amount": 200},
  {"description": "Item C", "amount": 300}
]

The response should remain unchanged.

Actual Result

The googleGenAIIntegration wraps each element in an additional array:

[
  [{"description": "Item A", "amount": 100}],
  [{"description": "Item B", "amount": 200}],
  [{"description": "Item C", "amount": 300}]
]

Additional Context

• Single-element arrays are NOT affected - only multi-element arrays
• Single objects are NOT affected
• The bug appears to occur during response instrumentation for recording purposes
• Workaround: Normalize the response by detecting and flattening the nested array pattern:

function normalizeArrayResponse(data: any): any {
    if (!Array.isArray(data)) return data;
    
    const isBugPattern = data.length > 1 && data.every(
        (item) => Array.isArray(item) && item.length === 1 && 
                  typeof item[0] === 'object' && item[0] !== null
    );
    
    return isBugPattern ? data.map((item) => item[0]) : data;
}

Environment

• Node.js version: 22.x
• Runtime: AWS Lambda
• @sentry/aws-serverless: 10.33.0
• @google/genai: 1.15.0

Priority

_{React with 👍 to help prioritize this issue. Please use comments to provide useful context, avoiding +1 or me too, to help us triage it.}

[linear]

JS-1448

[RulaKhaled]

Hello @arik-mesh, thank you for reaching out. We will look into it.

[nicohrubec]

Hello @arik-mesh, I am trying to reproduce this locally. How exactly are you calling the model? If you could share a code snippet that would be ideal.

[arik-mesh]

Closing this. Probably not related to Sentry. working with strict schema did the trick for me