Gemini API adds event-driven webhooks

This is a small-sounding API change that matters in production: it cuts wasted polling traffic, simplifies orchestration, and makes Gemini feel more like an operational platform than a chat endpoint.

• –Standard Webhooks signing plus at-least-once retries make the feature usable for real workflows, not just demos.
• –Project-level HMAC and per-request JWKS support both simple setups and routed, multi-tenant job handling.
• –The best fit is long-running work like Deep Research, video generation, and Batch API runs where polling is pure overhead.
• –It also narrows the ergonomics gap between Gemini and other serious AI APIs that already support event-driven completion handling.