Google Eliminates Polling in Gemini API with New Event-Driven Webhooks

Google Adds Event-Driven Webhooks to the Gemini API, Eliminating the Need for Polling in Long-Running AI Jobs

Google has introduced event-driven Webhooks for the Gemini API to fix the “polling problem” in production AI pipelines. This push-based system eliminates the need for repeated GET requests during asynchronous tasks like deep research or video generation.

Why This Matters

In high-volume AI workflows, polling for Long-Running Operations (LRO) can last for hours, consuming significant compute resources and API quota. By shifting to a push-based notification architecture, developers can reduce latency and eliminate the reliability headaches associated with maintaining polling loops at scale.

Key Insights

• Gemini API now supports the Standard Webhooks specification, utilizing webhook-signature, webhook-id, and webhook-timestamp headers to ensure idempotency.
• Static webhooks use HMAC with a symmetric shared secret for project-level integrations like Slack notifications or database synchronization.
• Dynamic webhooks utilize asymmetric JWKS (JSON Web Key Set) signatures for request-level routing, allowing developers to pass a URL in the webhook_config payload.
• The system uses a ‘thin payload’ model, delivering status pointers such as output_file_uri or video_uri instead of raw result data to minimize bandwidth congestion.
• Google provides an ‘at-least-once’ delivery guarantee with automatic retries via exponential backoff for up to 24 hours if the listener fails to respond with a 2xx status.

Practical Applications

• Use case: Processing thousands of prompts via the Batch API where batch.completed events trigger downstream file retrieval from Cloud Storage. Pitfall: Failing to respond with a 2xx status code immediately, which triggers unnecessary retry cycles.
• Use case: Agentic workflows using the Interactions API where interaction.requires_action notifies the application when a human-in-the-loop function call is pending. Pitfall: Trusting incoming requests without validating the webhook-timestamp header, leaving the endpoint vulnerable to replay attacks.

References:

• https://www.marktechpost.com/2026/05/05/google-adds-event-driven-webhooks-to-the-gemini-api-eliminating-the-need-for-polling-in-long-running-ai-jobs/