Antigravity Agents

Eliminate up to ~70% of Antigravity's hidden turn-zero context tax with near-zero loss in functionality.

Every time you launch a default Google Antigravity session, the platform silently injects ~14,000 input tokens of verbose tool descriptor schemas, prescriptive web-styling rules, and unused feature manifests before you even write your first prompt.

This repository provides two high-performance, context-disciplined custom agents tailored for maximum token runway while retaining all native Google Antigravity OAuth subscription benefits.

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Turn-0 Benchmark (agy v1.2.2)

# Verify programmatically on your own machine:
agy --agent better-agy --output-format json -p "Output 'PONG' and nothing else"
agy --agent lean-agy   --output-format json -p "Output 'PONG' and nothing else"

Agent Configuration	Turn-0 Base Tokens	Context Tax Reduction	Architecture & Trade-Off
Default Antigravity Agent	13,728 tokens	Baseline	17 built-in tools with full schema overhead + default boilerplate
better-agy	6,196 tokens	-7,532 tokens (~54.9% cut)	11 tools; retains native IDE subagent orchestration tools & UI panels; excludes prompt boilerplate
lean-agy	4,078 tokens	-9,650 tokens (~70.3% cut)	6 core tools; excludes prompt boilerplate; subagent delegation offloaded to on-demand agy-subagents skill

(Run the /context slash command inside any interactive session to inspect your live breakdown).

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🔍 Verbatim Turn-0 Context & Subsets

Both custom agents are strict functional subsets of the default Antigravity runtime context:

• 📄 Turn-0 Context Specification: Verbatim dump and token accounting for all 17 tool parameter schemas and system prompt XML blocks.
• 🎨 Interactive Turn-0 Overlay (docs/index.html): Interactive visualizer with segmented toggles to inspect verbatim Turn-0 context and active/pruned subsets across all three profiles.

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⚡ 1-Line Installation

Linux

curl -fsSL https://raw.githubusercontent.com/eggmasonvalue/antigravity-agents/main/scripts/install.sh | bash

Windows (PowerShell)

irm https://raw.githubusercontent.com/eggmasonvalue/antigravity-agents/main/scripts/install.ps1 | iex

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Included Agents

1. better-agy (Balanced + UI Subagents)

A lightweight software engineering agent for users who want token savings while keeping native subagent tools and IDE side-panel integration.

• Tools Kept (11): run_command, view_file, replace_file_content, write_to_file, search_web, read_url_content, invoke_subagent, define_subagent, send_message, manage_subagents, manage_task.
• Pruned (6): list_dir, grep_search, find_by_name (subsumed by shell), ask_question (plain chat), generate_image, schedule.
• System Prompt: Uses excludeDefaultComponents: true to prune ~3,000 tokens of verbose formatting rules.

2. lean-agy (Ultra-Minimal Shell-First + Skill-Driven Subagents)

An ultra-lean agent for maximum context runway. Drops all built-in subagent tool schemas from the system prompt on Turn 0. When delegation or parallelization is needed, it dynamically leverages the agy-subagents skill via run_command.

• Tools Kept (6): run_command, view_file, replace_file_content, write_to_file, search_web, read_url_content.
• Pruned (11): All subagent orchestration schemas and non-essential tools.
• System Prompt: Uses excludeDefaultComponents: true to prune ~3,000 tokens of verbose formatting rules.

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Included Skills

agy-subagents

A recipe-backed skill for orchestrating isolated CLI subagents, multi-turn steerable sessions (--conversation), background workers, and isolated git worktrees via run_command.

Note

Skill Scoping in Antigravity: Antigravity discovers and registers skills globally (~/.gemini/config/skills/) or per-workspace (.agents/skills/) across all active agent profiles (including better-agy and the default agent), as the platform does not currently support per-agent skill scoping or frontmatter filtering. However, thanks to progressive disclosure, only the skill name and short description are injected on Turn 0 (~50 tokens), avoiding the heavy ~2,000+ token tax of native subagent tool schemas.

agent-maintenance

An audit and synchronization skill to review and update agent configurations following agy CLI version upgrades or tool schema adjustments.

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Usage

Launch directly as your primary session agent:

# Launch balanced agent
agy --agent better-agy

# Launch ultra-minimal agent
agy --agent lean-agy

Or select either agent via the interactive /agents panel inside the CLI.

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Local Development & Testing

To test or install from a local checkout:

• Linux: ./scripts/install.sh --local
• Windows: .\scripts\install.ps1 -Local