Migrate from Gemini CLI to Antigravity CLI (2026): Config, MCP, Skills, Flags

Google announced the move from Gemini CLI to Antigravity CLI on May 19, 2026. On June 18, 2026, Gemini CLI stopped serving requests for Google AI Pro, Google AI Ultra, and free tier individual accounts.

• Must migrate: Google AI Pro, Google AI Ultra, and free tier individual accounts.
• Also affected: Gemini CLI used through Gemini Code Assist IDE extensions and Gemini Code Assist on GitHub.
• Not affected: organizations using a Gemini Code Assist Standard or Enterprise license, and access through Google Cloud.
• Not affected: Gemini CLI used with paid Gemini or Gemini Enterprise Agent Platform API keys.
• Gemini CLI stays available as an Apache 2.0 licensed repository on GitHub.

Antigravity CLI keeps Agent Skills, Hooks, Subagents, and Extensions. Extensions are now called Antigravity plugins.

curl -fsSL https://antigravity.google/cli/install.sh | bash
agy --version

The binary installs to ~/.local/bin/agy by default. Run agy in a project directory to open the interactive TUI. On first launch you pick a color scheme and rendering mode and confirm that you trust the workspace. Windows install commands are on the Get started page under the PowerShell and CMD tabs.

With no saved session, agy opens your default browser for Google sign-in. Over SSH it prints an authorization URL; open it on your local machine and paste the code it shows back into the remote terminal. Credentials are kept in the OS keyring. Use /logout to sign out.

To use a Gemini API key instead, set modelProvider in settings and export GEMINI_API_KEY. Setting the variable alone does nothing, and .env files are not loaded.

{
  "modelProvider": "gemini"
}

export GEMINI_API_KEY="your-api-key"
agy

For Application Default Credentials, run gcloud auth application-default login --project YOUR_PROJECT and export AGY_ADC_AUTH=true.

When agy first starts in an environment that has legacy Gemini CLI configs, it shows an interactive checklist: pick the extensions and global configurations to convert, move active session tokens into the OS keyring, and map visual and rendering defaults to your new settings profile.

agy plugin import gemini

The import converts Gemini extensions into native Antigravity plugins. Legacy custom commands inside them are converted to skills, and MCP server definitions bundled in an extension are migrated to mcp_config.json.

• ~/.gemini/settings.json: Antigravity CLI settings live in ~/.gemini/antigravity-cli/settings.json. Open them with /settings or /config.
• MCP servers (inline in ~/.gemini/settings.json): now defined in ~/.gemini/config/mcp_config.json (global) or .agents/mcp_config.json (workspace).
• GEMINI.md and AGENTS.md: no change. Workspace GEMINI.md and AGENTS.md files are still read, and global ~/.gemini/GEMINI.md is still consulted.
• ~/.gemini/skills/: move to ~/.gemini/antigravity-cli/skills/.
• .gemini/skills/: rename or move to .agents/skills/ so the agent recognizes them.
• Extensions: become plugins via agy plugin import gemini. Workspace plugins go in .agents/plugins/, global plugins in ~/.gemini/config/plugins/.
• Subagents: .agents/agents/<name>.md or .agents/agents/<name>/agent.md in the workspace, or ~/.gemini/config/agents/ globally.
• Hooks: .agents/hooks.json, ~/.gemini/config/hooks.json, ~/.gemini/antigravity-cli/settings.json, or a plugin's hooks.json. List them with /hooks.

For remote WebSocket or SSE servers, replace the legacy url or httpUrl key with serverUrl. Keep the mcpServers wrapper.

{
  "mcpServers": {
    "remote-indexer": {
      "serverUrl": "https://mcp.internal.enterprise.com/sse",
      "env": {
        "AUTH_TOKEN": "secure_alpha_token"
      }
    }
  }
}

Headless runs still use -p (aliases --print and --prompt). Output is set with --output-format text (default), json, or stream-json. --print-timeout defaults to 5m.

agy -p "Run the test suite and report failures" --output-format json

• In headless runs, a tool that needs approval is soft-denied: the run continues, exits 0, and writes a notice naming the tool to stderr. Reading and writing files in the workspace is auto-allowed, but shell commands default to Ask, so they are soft-denied unless you grant them.
• A run that produces no response exits non-zero and writes the reason to stderr.
• --dangerously-skip-permissions approves all tool calls, including file writes and command execution. Prefer scoped permissions.allow rules in ~/.gemini/antigravity-cli/settings.json, such as command(git).
• Execution modes are default, accept-edits, and plan. Set them with --mode, the agentMode setting, /settings, or Shift+Tab. --permission-mode is not valid.
• Tool permission rules still apply to shell commands in every mode.
• --sandbox runs the agent with terminal sandbox restrictions. Sandbox is a permission setting configured in /permissions, not an execution mode.

• Workspace skills in .gemini/skills/ are not recognized until you move them to .agents/skills/.
• Remote MCP servers using url or httpUrl need the serverUrl key.
• GEMINI_API_KEY is ignored unless modelProvider is set to gemini.
• Some custom terminal themes and experimental visual overlays from Gemini CLI may not carry over.
• Headless scripts that run shell commands need permissions.allow rules or they will be soft-denied while still exiting 0.

• Gemini CLI settings.json
• Gemini CLI MCP servers
• Gemini CLI GEMINI.md
• Gemini CLI custom commands
• Gemini CLI headless mode
• Antigravity CLI harness