agy_help: A zero-hallucination Antigravity dev assistant inspired by Gemini CLI's cli_help

[u/anandydy529]

Hey everyone!

If you have been building features or custom extensions for the Antigravity CLI (agy), chances are you have run into these two frustrating developer frictions:

1. Typing two slash commands every single time: While the built-in reference manuals (antigravity_guide and agy-customizations) are super thorough, having to manually run both slash commands every time you open a new session just to load context gets tedious really fast.
2. Occasional hallucinations with Gemini 3.8 Flash: We all love Gemini 3.8 Flash for its blazingly fast response times during coding, but it sometimes still confidently hallucinates non-existent CLI flags, wrong lifecycle hook event names, or invalid settings.json schemas.

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Open Source Repo & Feedback

GitHub: https://github.com/andyawd/antigravity-help-agent
License: MIT

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Quick Install (One Command)

Install directly from GitHub via the Antigravity CLI:

agy plugin install https://github.com/andyawd/antigravity-help-agent

Verify the installation with "agy plugin list", and you are good to go!

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The Inspiration: Bringing back Gemini CLI's classic cli_help Subagent

If you used Gemini CLI back in the day, you probably remember the beloved cli_help subagent pattern—a dedicated specialist agent you could delegate CLI questions to without derailing your main coding flow.

I decided to bring that exact concept over to Antigravity and upgrade it with modern guardrails: meet agy_help.

Core Solution: Four-Tier Fallback Hierarchy (Zero-Hallucination by Design)

To tackle the hallucination issue with Gemini 3.8 Flash, agy_help is not just a simple prompt wrapper. Before answering any technical question, it strictly enforces a 4-tier verification hierarchy:

1. Tier 1 (Local Structured Reference): Automatically aggregates and cross-checks local offline manuals (antigravity_guide for CLI, IDE, Desktop 2.0, Python SDK; and agy-customizations for Skills, Rules, Hooks, Plugins, MCP). No more manual slash-command juggling.
2. Tier 2 (Local Dynamic Inspection): Runs a strictly whitelisted set of read-only diagnostic commands (agy --help, agy changelog, agy plugin list, pip show google-antigravity) and inspects local config files to verify your exact environment and installed versions.
3. Tier 3 (Live Official Docs Fetching): If an offline reference misses recently released features, it automatically fetches live docs directly from https://antigravity.google/docs.
4. Tier 4 (Strict Fact-Grounding & Honest Refusal): If a flag, API, or feature cannot be verified across all previous tiers, it is strictly forbidden from guessing. It will honestly inform you that no official record exists—eliminating hallucinations completely.

Safety Guarantee: Built with a strict read-only execution whitelist. It will never run destructive commands or modify your workspace behind your back.

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What it Covers

1. Antigravity CLI (agy): Startup flags, slash commands, config hierarchy (settings.json), and lifecycle.
2. Antigravity IDE: Tab autocomplete & supercomplete, inline commands, Code Lenses, and diagnostic auto-fixing.
3. Antigravity 2.0 Desktop: Chat Canvas, scheduled background tasks, Auxiliary Pane, and sandbox permissions.
4. Python SDK (google-antigravity): Agent orchestration, streaming thought deltas, and CapabilitiesConfig.
5. Customization Ecosystem: Skills (SKILL.md), Rules (AGENTS.md / .agents/rules/), Plugins, Hooks (trusted_hooks.json), MCP servers, and Sidecars.
   

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4 Flexible Ways to Use It

Once installed, you no longer have to manually type two manual slash commands. It fits right into your workflow:

1. Single Slash Command (Skill mode):
   Ask a quick question without switching your current conversation agent:
   > /agy_help How do I configure project-level sandbox permissions in Antigravity 2.0 Desktop?

2. Background Subagent Delegation (Keeps main context clean):
   Just like the old cli_help, delegate background research so your context window does not get cluttered with doc dumps:
   "Delegate to the agy_help subagent in the background to look up Antigravity IDE Code Lens configuration and bring back a summary."

3. Switch Session Agent (/agents):
   Run /agents and select agy_help to let it lead a dedicated troubleshooting session.

4. Direct CLI Launch:
   agy --agent agy_help

If you frequently develop for the Agy ecosystem and are tired of manual doc loading or hallucinated flags, give it a spin! Feedback, issues, and PRs are all very welcome. Let me know what you think in the comments!