By ByteBot
Google is shutting down Gemini CLI on June 18 — nine days from now. Free, Pro, and Ultra users lose access when the cutover happens. The replacement is Antigravity CLI (agy), a closed-source Go rewrite announced at I/O 2026. It keeps most of what you know but breaks four things quietly, including one that fails with zero error output. If you have CI pipelines or shell scripts calling gemini, they stop working on that date. The migration takes 15 minutes. Not doing it costs more.
Who Needs to Act
If you use Gemini CLI through a personal Google account — free, AI Pro, or AI Ultra — you must migrate before June 18. If your organization is on a Gemini Code Assist Standard or Enterprise license, you are exempt and nothing changes on your end.
Everyone else: the clock is running.
The Four Breaking Changes
Antigravity CLI is not a rename. It is a closed-source rewrite in Go — new binary (agy), new config layout, and four behavioral differences that will break existing setups:
- Default model: Gemini CLI defaulted to
gemini-1.5-pro. Antigravity defaults togemini-3-pro. Scripts tuned to the old model’s speed and cost profile will behave differently. - Streaming format: The old
--streamflag emitted plain text deltas. Antigravity emits SSE-formatted events. Any script parsing streaming output breaks. - State directory: Agent state moved from
~/.gemini/agents/to~/.antigravity/agents/. Your existing agent state is not automatically migrated. - Exit codes: Gemini CLI exited
0on tool-use failures. Antigravity exits non-zero. CI pipelines that relied on silent success behavior now fail loudly — or halt entirely if you haveset -e.
The Silent Failure You Must Not Miss
The MCP configuration change is the most dangerous part of this migration, because it fails with no error output.
Gemini CLI stored MCP server configuration inline in settings.json using a field called url. Antigravity CLI uses a separate mcp_config.json file, and the field is now called serverUrl.
Here is what the same server entry looks like in each tool:
Gemini CLI (settings.json)
{
"mcpServers": {
"my-server": {
"url": "https://my-mcp-server.example.com"
}
}
}Antigravity CLI (mcp_config.json)
{
"mcpServers": {
"my-server": {
"serverUrl": "https://my-mcp-server.example.com"
}
}
}If you copy the config without renaming the field, agy starts cleanly with no warnings, the MCP server does not connect, and your agent runs without the tool it expects — silently producing wrong results. You find out when something downstream breaks, not at startup.
Rename url to serverUrl. This is the step most people miss.
How to Migrate (15 Minutes)
1. Install Antigravity CLI
# macOS / Linux
curl -fsSL https://antigravity.google/cli/install.sh | bash
# Windows
curl -fsSL https://antigravity.google/cli/install.cmd -o install.cmd && install.cmd && del install.cmdThe binary lands at ~/.local/bin/agy on Unix. Add it to your PATH if needed, restart your terminal, then run agy --version to confirm. First run opens an OAuth browser flow, or prints an auth URL and OTP code if you are on a headless server.
2. Update environment variables
Replace these in your shell profile, CI secrets, and Docker environment configs:
| Old variable | New variable |
|---|---|
GEMINI_API_KEY | AV_API_KEY |
GEMINI_PROJECT_ID | AV_PROJECT_ID |
GEMINI_REGION | AV_REGION (default: us-central1) |
3. Migrate MCP config
Create ~/.antigravity/mcp_config.json, copy your MCP server entries from the old settings.json, and rename every url field to serverUrl. Do not just copy and assume it works — run a task that calls the tool to verify the connection. Startup success does not mean the MCP server connected.
4. Move skills
mv ~/.gemini/skills/ ~/.agents/skills/5. Update CI pipelines and scripts
Find every place your automation calls gemini and replace it with agy. This includes shell scripts, GitHub Actions workflows, cron jobs, and Makefile targets. The migration script handles your local config but does not touch automation. Those pipelines are a silent time bomb if you skip this step.
The Honest Take
The “bait-and-switch” criticism is fair. Gemini CLI was open-source TypeScript with over 6,000 community-merged pull requests. Antigravity CLI is a closed-source Go rewrite. Google absorbed years of community labor and shipped a proprietary product in return. The community discussion on GitHub reflects genuine and reasonable frustration, as does the broader reaction on Hacker News.
Google has also cut Antigravity’s usage quotas four times since December 2025, without advance notice. Pro subscribers went from effectively unlimited Gemini model access to weekly rate caps that hit mid-workday. That track record earns skepticism.
That said, Antigravity CLI is functionally better in the ways that count: parallel subagents, scheduled background tasks, and a faster Go-based binary are real improvements. The open-source loss is a legitimate grievance. It does not make migrating optional.
Do This Before June 18
The migration is 15 minutes for a solo setup and a few hours for teams auditing multiple CI pipelines. The MCP serverUrl rename is the step most likely to cause silent failures — test it explicitly by running a real task after migration, not just checking that agy starts. Google’s official migration documentation covers the full config reference, and the Google Developers Blog announcement has the official scope of what changes. The migration walkthrough at agentpedia.codes goes deep on edge cases worth reading before you start.
Enterprise licenses: nothing changes. Everyone else: agy is your new terminal agent. June 18 is not a soft deadline.
