Migrating from Gemini CLI to Antigravity CLI (agy): A Flutter Dev's Checklist

Following the official sunset of Gemini CLI on June 18, 2026, Google has consolidated all AI developer tooling into the Google Antigravity ecosystem. For Flutter developers using the legacy CLI, migrating to Antigravity brings significantly upgraded agentic capabilities across four primary surfaces.

The 4 Antigravity Surfaces

1. Antigravity Desktop: An IDE environment with an integrated agent panel, diff viewer, and visual agent trajectory timeline.
2. Antigravity CLI (agy): A ultra-fast, terminal-first agentic tool written in Go that runs agent loops directly in your shell.
3. Antigravity SDK: A programmatic library for triggering custom agent workflows inside CI/CD pipelines.
4. Managed Agents: Cloud-isolated environment instances spun up on demand via API for heavy background tasks.

Migration Checklist for Flutter Projects

• 1. Remove Legacy Gemini CLI Hooks: Uninstall old CLI packages and clean up deprecated env variables.
• 2. Install the agy Go CLI: Run brew install google-antigravity/tap/agy or download the native binary.
• 3. Convert Project Context to AGENTS.md: Transfer custom prompt rules into a root AGENTS.md file.
• 4. Configure Flutter MCP Servers: Enable Dart and Stitch MCP plugins in your ~/.config/antigravity/mcp.json configuration.
• 5. Verify CI/CD Integration: Update GitHub Actions or Codemagic pipelines to use the Antigravity SDK for automated code reviews.