Using agent-skills with Antigravity CLI (agy)

The agent-skills package can be installed as a native plugin in the Antigravity CLI (agy), giving the agent access to structured workflows and personas.

Setup

Option 1: Native Plugin Installation (Recommended)

Antigravity CLI has a first-class plugin system that registers skills and agents. The repository also carries legacy command TOMLs, but affected agy releases do not expose their converted wrappers; see Lifecycle Workflows and Command Compatibility.

Install from the remote repository:

agy plugin install https://github.com/addyosmani/agent-skills.git

Install from a local clone:

1. Clone the repository:

   git clone https://github.com/addyosmani/agent-skills.git
   

2. Install the plugin using agy:

   agy plugin install /path/to/agent-skills
   

This will validate the plugin and install it into your global Antigravity configuration directory (~/.gemini/config/plugins/agent-skills/).

Note: on current agy releases the plugin lands under ~/.gemini/config/plugins/, not the legacy ~/.gemini/antigravity-cli/plugins/ path used by older versions. If you don't see the plugin at the legacy path, check ~/.gemini/config/plugins/agent-skills/ first.

Option 2: Import from Gemini CLI

If you have already installed agent-skills under your legacy Gemini CLI installation, you can import it directly:

agy plugin import gemini

Once installed, verify the active plugin:

agy plugin list

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Lifecycle Workflows and Command Compatibility

Antigravity's migration tooling reports the 9 legacy definitions in commands/*.toml as "converted to skills." In affected agy 1.1.x releases, validation succeeds but the converted wrappers do not appear in the slash-command or skill catalog. A successful agy plugin validate therefore confirms the files are well formed, not that /build and the other short wrappers are available. This is tracked in agent-skills #445 and upstream in antigravity-cli #788.

Use the native plugin skills directly while that importer limitation applies:

Intended wrapper	Direct Antigravity invocation	Notes
/spec	/agent-skills:spec-driven-development	Writes a structured spec before code
/constraints	/agent-skills:constraint-driven-development	Defines and enforces the project's quality bar
/planning	/agent-skills:planning-and-task-breakdown	Antigravity's built-in /planning command is a separate plan-mode control
/build	/agent-skills:incremental-implementation	Also invoke /agent-skills:test-driven-development; wrapper-only /build auto orchestration is unavailable
/test	/agent-skills:test-driven-development	Runs the red-green-refactor workflow
/review	/agent-skills:code-review-and-quality	Runs the five-axis review workflow
/code-simplify	/agent-skills:code-simplification	Simplifies without changing behavior
/ship	/agent-skills:shipping-and-launch	The wrapper's automatic persona fan-out is unavailable; invoke specialist agents separately
/webperf	Select web-performance-auditor from /agents	This workflow is a persona, not a skill

Do not add YAML frontmatter to the TOML files as a workaround. Gemini CLI reads the parallel TOML command format with a strict parser, and --- frontmatter makes those files invalid TOML without changing Antigravity's conversion behavior.

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Skills & Discovery

Antigravity automatically discovers skills inside the plugin's skills/ directory.

• Antigravity matches user tasks and intents to relevant skills on-demand.
• If a task matches a skill, the agent will load the skill and prompt you for permission before executing.

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Verification & Validation

To validate that your local plugin is correctly structured and contains all skills, run:

agy plugin validate /path/to/agent-skills

Then start a fresh session and type /agent-skills: to inspect the namespaced skill catalog. If the validator reports that commands were converted but /build returns No matches, use the direct invocations above; reinstalling or adding a TOML name field does not resolve the known importer limitation.

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How It Works

1. On-Demand Skill Activation

Antigravity CLI automatically discovers the SKILL.md files located in the skills/ directory of the installed plugin. Using the trigger descriptions in each skill's frontmatter, the agent will dynamically activate the appropriate workflow when it detects matching developer intent.

For example, when you ask the agent to:

• Design a new system → It will suggest/activate spec-driven-development.
• Implement a feature → It will activate incremental-implementation and test-driven-development.
• Fix a bug → It will activate debugging-and-error-recovery.

2. Specialized Agent Personas

The plugin registers reusable subagent definitions from the agents/ directory:

• code-reviewer.md
• security-auditor.md
• test-engineer.md

You can invoke these personas directly within your session or when delegating tasks using subagents.

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Configuration & Customization

Project-Specific Enforcements (AGENTS.md)

To enforce strict skill compliance (e.g. requiring a spec or plan before writing code), copy or link AGENTS.md into the root of your workspace. Antigravity CLI reads this file to align the agent's behavior and planning phase with your team's conventions.

Sandbox Mode

If you want to run skills or scripts with limited terminal permissions (for safety when running third-party validation tests), launch the CLI with:

agy --sandbox

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Usage Tips

1. Keep plugins up-to-date: You can update the CLI or check for newer plugin versions using:

   agy update
   

2. Review before execution: When agents execute complex refactoring tasks using these skills, use Ctrl+r to enter the Artifact Review screen to review, edit, or approve code before it is committed.
3. Control permissions: You can use the --dangerously-skip-permissions flag only in trusted local projects where you want to bypass manual tool approval prompts.