Antigravity CLI Migration for Game Developers - What Changed in 2026

Antigravity CLI migration is no longer optional for many indie developers. On June 18, 2026, Google stopped serving Gemini CLI and Gemini Code Assist IDE extensions for individual, Google AI Pro, and Google AI Ultra accounts. Login-with-Google paths that worked in early 2026 now fail or redirect. Google directs affected users to Antigravity and Antigravity CLI — a Go-based terminal agent that shares a harness with Antigravity 2.0 desktop.

That is not a rename. It is a product split. Enterprise Gemini Code Assist Standard and Enterprise subscriptions keep their existing CLI and IDE access. Solo developers and small studios on consumer Google accounts need a new install path, new auth, and often new CI scripts that still say gemini in the filename.

Official migration posts explain the platform direction. They rarely cover what game developers actually hit: Unity Library/ folders, Godot .import caches, Unreal Binaries/, generated shader folders, and team repos where one seat still uses enterprise Code Assist while another migrated to Antigravity. This article is that playbook — keep, hold, or rewrite; a 30-minute smoke test; repo boundaries; pairing with Cursor, Aider, or Qwen Code; and a receipt your lead can file before calling the migration done.

If you are still choosing tools, start with our best AI coding assistants 2026 comparison. This URL is the migration implementation guide for Google's new terminal path.

Why this matters now

Three dated signals make July 2026 the operational deadline — not May's announcement alone:

1. Consumer sunset executed June 18 — Google's deprecation doc confirms Gemini CLI and consumer IDE extensions no longer serve individual, Pro, or Ultra login paths. Scripts and aliases that call gemini on those accounts break without a config change.
2. Antigravity CLI is the unified successor — Google's May 19, 2026 developers blog positions Antigravity CLI as the terminal surface sharing Antigravity 2.0's agent harness, with async multi-agent workflows, Go-based performance, and plugins replacing Gemini extensions.
3. Installed base pressure is real — the legacy google-gemini/gemini-cli repository reports more than 106,000 GitHub stars. That is not abstract hype; it is thousands of README snippets, shell aliases, and CI jobs that still reference the old binary name.

Who this is for: indie leads, technical directors, and solo creators who relied on Gemini CLI for terminal coding and now need a disciplined migration without breaking shared branches.

What you get: a keep/hold/rewrite decision table, a 30-minute beginner smoke path, four game-repo patterns, governance gates, and antigravity_cli_migration_receipt_v1.json.

Time: about 30–45 minutes for the beginner smoke test; add 60–90 minutes if you rewrite CI, team docs, and mixed enterprise/individual auth.

What changed - the split in plain language

Google is explicit that feature parity is not immediate. Agent Skills, Hooks, Subagents, and Extensions survive in renamed or evolved forms, but you should expect config rewrites — not a copy-paste of ~/.gemini/ into ~/.antigravity/ and a coffee break.

For game teams, the painful part is usually documentation debt: your internal wiki still says "run Gemini on the gameplay branch," your .github/workflows/ still caches the old npm global, and your .cursor/rules or AGENTS.md still reference @google/gemini-cli install lines from a 2025 tutorial.

Keep, hold, or rewrite - decision table for studios

Use this before you touch production repos:

Rule of thumb: if your last successful Gemini CLI session was before June 18 on a consumer account, assume rewrite, not hold.

Antigravity CLI at a glance (vs Gemini CLI)

Official references: transition blog, consumer deprecation FAQ, Antigravity CLI repository.

Beginner path - 30-minute migration smoke test

This is the shortest safe path from "my old login broke" to "Antigravity CLI edits one script file on a throwaway branch."

Prerequisites

• A Git game repo (Unity, Godot, Unreal, or custom engine) — or a tiny sample project.
• 30 minutes uninterrupted.
• Your new Antigravity account or enterprise Cloud project credentials per Google's current docs — not the deprecated consumer Gemini Code Assist login.
• A throwaway branch — never main, develop, or a fest demo branch.

Step 1 - Inventory what breaks

Before installing anything, grep your machine and repo:

# Shell aliases and PATH
type gemini 2>/dev/null || true
grep -r "gemini-cli" ~/.bashrc ~/.zshrc ~/.config 2>/dev/null | head

# Repo scripts and CI
grep -ri "gemini" .github/ scripts/ Makefile package.json 2>/dev/null | head -20

Write down every hit. Migration fails when you fix the interactive CLI but leave a nightly CI job calling the old binary.

Step 2 - Install Antigravity CLI from current docs

Google ships Antigravity CLI through paths documented at antigravity.google/docs/cli. Pin the version your receipt records — Antigravity is actively releasing (check github.com/google-antigravity/antigravity-cli/releases before standardizing).

Verify the binary responds:

antigravity --version
antigravity --help

If your team used a global npm install for Gemini CLI, remove or rename the old shim so gemini does not silently resolve to a broken 2025 binary.

Step 3 - Authenticate on the correct lane

Consumer migration and enterprise Cloud migration are different support paths. Read the FAQ on the deprecation page and confirm which lane your seat uses before you paste credentials into a shared machine.

For a first session, prefer a personal throwaway project directory, not a repo with production secrets or deployment keys.

Step 4 - Create an isolation branch

git checkout -b antigravity-smoke-2026-07-20
git status

Commit or stash dirty work. Game repos with large binary assets should still branch — agents should not edit .unity scenes on your first smoke test.

Step 5 - Run one bounded edit on a single code file

Pick one gameplay script — for example a Godot .gd file, a Unity .cs utility, or an Unreal .cpp with no engine-generated headers in scope.

In Antigravity CLI, keep the task narrow:

"Read only Scripts/VolumeSetting.cs. Add a clamp so volume stays between 0 and 1. Do not modify scenes, prefabs, packages, or generated folders."

Approve tool calls deliberately on the first run. You are testing auth + file boundaries + diff quality, not shipping a feature.

Step 6 - Reject or keep the diff

If the agent touched Library/, Binaries/, .godot/imported/, or Packages/, revert immediately:

git checkout -- .
git clean -fd   # only if you understand what will be deleted

A failed boundary test is useful data — update .gitignore and agent instructions before retrying.

Step 7 - File the smoke receipt

Complete gates A1–A6 below and save antigravity_cli_migration_receipt_v1.json. Set "result": "pass" only after human review.

Four game-dev migration patterns

Pattern 1 - Unity repos with generated noise

Unity projects tempt agents to "help" with Library/, Temp/, Logs/, and UserSettings/. Your migration README should list allowed edit roots:

• Assets/Scripts/
• Assets/Editor/ (only when explicitly in scope)
• Packages/manifest.json (hold — prefer human review)

Block everything under Library/ and Temp/ in both .gitignore and agent instructions. Pair Antigravity CLI with Unity MCP safe session when you need scene-level verification — terminal agents should not be your only Unity surface.

Pattern 2 - Godot 4.x repos and .import caches

Godot's .godot/ folder and imported assets confuse file-walking agents. Scope edits to *.gd, *.cs, and documented tool scripts. Run the editor once after migration to confirm imports still resolve — CLI diffs alone do not prove scenes load.

Pattern 3 - Unreal Engine and build artifacts

Unreal's Binaries/, Intermediate/, and DerivedDataCache/ are migration traps. Keep Antigravity sessions on Source/ gameplay modules. For editor bridge workflows, compare against Unreal MCP safe session rather than expecting the CLI to compile a full target unattended.

Pattern 4 - Mixed Google lanes on one team

When two developers use enterprise Code Assist and three use Antigravity consumer paths, split documentation:

• Enterprise lane: existing Gemini CLI + IDE extensions, org quotas, Cloud audit logs.
• Indie lane: Antigravity CLI, separate billing, separate API keys.

Never share one Google login across lanes to "save money." That creates un-auditable edits and violates most publisher diligence questionnaires.

Pairing Antigravity CLI with your existing stack

Antigravity CLI does not replace every tool in your stack. It replaces one broken login path for Google-terminal workflows.

Practical split many micro-studios use in July 2026:

• Cursor for hour-to-hour editing.
• One terminal agent (Antigravity, Aider, or Qwen) for bounded tasks on a branch.
• Receipt JSON so producers know which tool touched which commit.

See Aider's Git workflow and Qwen Code workflows for the non-Google terminal paths.

CI and shell script rewrites

Search-and-replace gemini → antigravity is not enough. Update:

1. Install step — new package/binary source from official docs; pin version.
2. Auth secret names — GEMINI_API_KEY env vars may need renaming per Antigravity's current headless auth.
3. Flags — subcommand names differ; read release notes before porting scripts.
4. Timeouts — async agent jobs may run longer; adjust CI job timeouts for research tasks.
5. Allowed paths — pass explicit file globs in prompts or wrapper scripts so CI never scans entire Assets/.

Example policy line for AGENTS.md:

## Terminal agents (July 2026)
- Consumer Gemini CLI: RETIRED 2026-06-18
- Approved Google terminal: Antigravity CLI (pinned vX.Y.Z)
- Allowed edit roots: Assets/Scripts/, Source/MyGame/
- Forbidden: Library/, Binaries/, .godot/imported/, **/*.uasset (binary)

Governance gates - A1 through A6

Do not mark migration complete until all six pass on a real repo:

Verification receipt - antigravity_cli_migration_receipt_v1.json

{
  "schema": "antigravity_cli_migration_receipt_v1",
  "project": "your-game-repo",
  "date": "2026-07-20",
  "antigravity_cli_version": "pinned-semver-here",
  "auth_lane": "consumer_antigravity",
  "previous_tool": "gemini_cli_consumer",
  "sunset_date": "2026-06-18",
  "branch": "antigravity-smoke-2026-07-20",
  "files_in_scope": ["Scripts/VolumeSetting.cs"],
  "ci_scripts_updated": true,
  "grep_gemini_residual": "changelog-only",
  "gates": {
    "A1_pin": true,
    "A2_auth_lane": true,
    "A3_scope": true,
    "A4_scripts": true,
    "A5_pairing": true,
    "A6_receipt": true
  },
  "smoke_task": "Single-file bounded edit with manual approval",
  "paired_tools": ["cursor"],
  "result": "pass",
  "operator": "session-owner-handle"
}

Set "result": "pass" only after human review and any engine smoke your team requires.

Enterprise and publisher diligence notes

When a platform partner or publisher asks "which AI tools touch your source repo," July 2026 Google migration adds questions:

• Which Google lane? Enterprise Code Assist vs Antigravity consumer — different data handling and support paths.
• Where do prompts go? Cite Google's current Antigravity and Cloud privacy docs for your lane; do not assume 2025 Gemini CLI answers.
• Who can install plugins? Antigravity plugins are the new extension surface — treat them like any third-party CI dependency.
• Audit trail — keep migration receipts and commit messages that name the agent session owner.

Companies evaluating your studio are not impressed by "we switched because Google forced us." They are impressed by documented lanes, pinned versions, and bounded edit roots.

Key takeaways

1. June 18, 2026 ended consumer Gemini CLI and Gemini Code Assist IDE logins — Antigravity CLI is the individual migration target.
2. Enterprise Code Assist Standard and Enterprise lanes continue; mixed teams need split documentation, not one shared Google login.
3. Run a 30-minute smoke test on a throwaway branch with one code file before touching fest or release branches.
4. Game repos need explicit edit roots — block Library/, Binaries/, and import caches on day one.
5. Rewrite CI and shell scripts — grep for gemini in .github/, scripts/, and dotfiles.
6. Feature parity is not instant — plan config rewrites for hooks, plugins, and subagents.
7. Pair Antigravity CLI with editor or Git-native tools — see best AI coding assistants for the full matrix.
8. File antigravity_cli_migration_receipt_v1.json with gates A1–A6 before calling migration production-safe.

Frequently asked questions

What is Antigravity CLI?

Antigravity CLI is Google's terminal agent for the Antigravity platform, introduced as the successor to Gemini CLI for many users. It shares an agent harness with Antigravity 2.0 desktop and supports async multi-agent workflows.

Do I need to migrate if I used Gemini CLI for free?

Yes, if you used Gemini CLI or Gemini Code Assist for individuals with Login with Google. Google stopped serving those requests on June 18, 2026. Migrate to Antigravity CLI or switch to a different assistant entirely.

Is Gemini CLI completely dead?

Not for everyone. Organizations on Gemini Code Assist Standard or Enterprise retain access. Paid Gemini and Gemini Enterprise Agent Platform API key paths also continue per Google's May 2026 announcement. Consumer individual accounts are the group that must move.

How do I migrate Gemini CLI settings to Antigravity CLI?

Google states there is not 1:1 feature parity at launch. Treat migration as reconfiguration: reinstall CLI from current docs, re-auth on the correct lane, rebuild plugin/extension equivalents, and re-test hooks and subagents on a throwaway branch. Do not assume copying ~/.gemini/ is sufficient.

Can I use Antigravity CLI with Unity or Godot?

Yes for source files on a bounded branch — scripts, shaders in text form, build configs you understand. Do not let the CLI bulk-edit scenes, prefabs, or generated engine folders on the first session. Pair with engine-specific guides like Unity MCP safe session when you need editor verification.

Should I use Antigravity CLI instead of Aider or Qwen Code?

Use Antigravity CLI if you are committed to Google's harness and account lane. Use Aider for Git-native undo semantics or Qwen Code for open CLI sub-agents and model fallback. Many teams run one editor tool plus one terminal tool, not every vendor at once.

Where do I get help if Antigravity CLI breaks?

Google directs users to the Antigravity CLI GitHub repository for support. Pin your version and attach receipt JSON when filing issues.

Conclusion

Google's Gemini CLI experiment proved terminal agents matter. The June 2026 sunset proves account lanes and harness choices matter more. Game developers feel that difference in CI jobs, .gitignore boundaries, and mixed teams where one seat still has enterprise Code Assist.

Migrate with discipline: inventory old gemini references, smoke-test Antigravity CLI on one script file, rewrite scripts, document pairing with your existing stack, and file the receipt. If Antigravity earns a permanent slot, compare it honestly against your 2026 AI coding assistant lineup before you add overlapping subscriptions.

Related reading and sources

• Best AI coding assistants 2026
• Aider AI coding assistant workflow for game developers
• Qwen Code CLI workflows
• Cursor AI pair programming for Unity prototypes
• 50 free AI tools for game developers
• Transitioning Gemini CLI to Antigravity CLI - Google Developers Blog
• Gemini Code Assist for individuals deprecation
• Antigravity CLI on GitHub