Are Webhooks API supported for Vertex AI batch jobs?

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1

I’m using @google/genai with vertexai: true for batch prediction jobs with GCS input/output.

I’d like to receive batch.succeeded / batch.failed notifications via webhook instead of polling. However, webhooks.create returns 404 in Vertex AI mode:

import { GoogleGenAI } from '@google/genai';

const client = new GoogleGenAI({
  vertexai: true,
  project: ‘my-project’,
  location: ‘global’
});

await client.webhooks.create({
  name: ‘my-webhook’,
  subscribed_events: [‘batch.succeeded’, ‘batch.failed’],
  uri: ‘https//example.com/webhook’
});
// → 404

The Webhooks API docs (https//ai.google.dev/gemini-api/docs/webhooks) seem to cover the Developer API only. Is this correct — webhooks are not available for Vertex AI?