Google previews Gemini Spark and shifts CLI users to Antigravity

Google used I/O 2026 to preview Gemini Spark, a hosted AI agent the company describes as “your personal AI agent” for Google apps. The product is not generally available yet, and the details come from Google’s announcement materials and related cloud documentation rather than hands-on testing.

According to Google, Gemini Spark will connect natively with Gmail, Calendar, Drive, Docs, Sheets, Slides, YouTube, and Google Maps. That positions it as a consumer- and work-facing assistant that can act across the company’s own services, rather than a general-purpose chatbot that only answers questions in a chat window.

Google’s FAQ also says Gemini Spark runs on Gemini 3.5 Flash and Antigravity. That raised questions because Antigravity is also the name of several tools listed on antigravity.google, including a desktop app, a CLI agent tool written in Go, an SDK, and an IDE based on a VS Code fork.

Google has not fully explained which part of Antigravity powers Spark, but the documentation suggests the hosted agent may be built on the same Go binary behind the newer tooling. The FAQ wording is unusual, because it mixes a user-facing product name with an internal platform name and offers little clarity on how those layers fit together.

Security is likely to be a major issue for Spark, especially if users connect it to mail, documents, and calendars that contain sensitive data. In a Google Cloud post aimed at enterprise customers, the company said Spark runs in a fully managed secure runtime on Google Cloud.

Google said each task runs in a fresh, strictly isolated, ephemeral virtual machine, or VM, to prevent data from overlapping between sessions. The company also said all traffic passes through a secure Agent Gateway that enforces Data Loss Prevention, or DLP, policies, while user credentials stay fully encrypted and are never exposed directly to the agent.

That is the main signal Google gave on prompt-injection risk and data handling. The company did not publish a full technical threat model in the material cited here, but it is clearly trying to frame Spark as an enterprise-safe agent rather than a consumer experiment.

Google also announced a change for CLI users. In a post about moving Gemini CLI to Antigravity CLI, the company said the open source Gemini CLI tool, licensed under Apache 2.0 and written in TypeScript, will stop working with Google AI subscription plans on June 18.

It will be replaced by the closed source Antigravity CLI. That means users who built workflows around the old CLI will need to migrate to Google’s new tooling if they want to keep using subscription-based access.

The broader picture from I/O is that Google is tying its agent plans more tightly to its own cloud runtime, app ecosystem, and toolchain. For now, the most concrete parts are the Spark preview, the security claims in the Cloud post, and the deadline for Gemini CLI users to move to Antigravity CLI.