Preventing Quota Crashes via Antigravity CLI Agent Hooks

Solving the LLM quota monitoring paradox with zero-overhead local Connect RPC agent hooks. Abstract Google Antigravity CLI users using Google OAuth face abrupt task failures when API quota hits 0%, while account switching triggers unrecoverable signature errors. Querying quota via LLM tool calls creates a paradox by consuming the very tokens being monitored. We resolve this with antigravity-cli-check-usage-plugin, a CLI Agent Hook running outside the LLM execution turn. Directly querying local Connect RPC endpoints, it monitors quota with zero token overhead and injects proactive warning banners when threshold limits are reached. 1. Introduction Developers relying on Google Antigravity CLI for autonomous pair programming frequently encounter a frustrating barrier: running out of API quota mid-session. When using Google OAuth authentication, your quota can silently hit 0%, causing task execution to halt abruptly with an unrecoverable quota error: