The Zero-Quota Trap in Google Antigravity: How I Built an Autonomous Multi-Account Skill

A deep dive into the 5-hour rolling limit versus weekly quota blindspot in Google Antigravity, and how I built an open-source agent skill for zero-touch account rotation in Antigravity IDE.

Yasir Najeep

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The Zero-Quota Trap in Google Antigravity: How I Built an Autonomous Multi-Account Skill

When coding extensively with AI agents in Google Antigravity, few things disrupt developer flow state as abruptly as an unexpected quota brick wall: HTTP 429 Resource Exhausted / Quota Exceeded.

To maintain uninterrupted development, many engineers register multiple Google AI accounts (Pro or Starter) and configure proxy servers to balance requests. Yet in real production workloads, developers frequently discover that all promises of “full autopilot” collapse at the most critical moment: when an active account exhausts its quota, the editor halts, forcing the developer to exit their workflow, open management GUIs, manually find an account with remaining quota, click switch, and restart the editor.

This recurring friction led me to dissect the underlying token routing and credential storage architecture, uncover a hidden quota blindspot, and engineer an open-source skill called Antigravity Autopilot for true zero-touch rotation.

The skill is fully open source under the MIT license on GitHub and adheres to the open Agent Skills specification.

The Root Causes: Why Conventional Rotation Fails

Analyzing account management daemons and proxy routing code revealed two fundamental structural flaws:

1. The 5-Hour vs. Weekly Quota Blindspot

Google Antigravity enforces two independent quota buckets for model families:

  • The Rolling 5-Hour Bucket: Refreshes continuously on a rolling 5-hour window.
  • The Hard Weekly Bucket: A fixed weekly allocation across the billing cycle.

Most manager tools calculate an account’s health percentage by examining only the 5-hour rolling bucket. If an account exhausts its weekly quota (0.0%), but its 5-hour rolling window elapses and resets, the management UI displays 100% available quota.

As a result, proxy routers mistakenly treat depleted accounts as healthy, continually dispatching requests directly into immediate HTTP 429 rejections. Preemptive quota protection never engages because the algorithm falsely assumes the account has 100% capacity.

2. The IDE Active Credential Lock

Antigravity IDE (built on Electron and the VS Code architecture) stores active OAuth session credentials directly in operating system keystores:

  • macOS Keychain: Service gemini under account antigravity.
  • Internal SQLite Database: state.vscdb.

Standard HTTP proxies only intercept traffic routed through local ports; they have no ability to update the active session credentials inside the running editor. When the account currently driving an interactive chat conversation depletes, the editor freezes until the developer performs a manual credential swap.

The Solution: A Three-Tier Autonomous Controller

Antigravity Autopilot operates continuously in the background on macOS, organized across three cohesive layers:

┌────────────────────────────────────────────────────────────────────────┐
│               Continuous 60s Watcher (com.antigravity.controller)       │
├────────────────────────────────────────────────────────────────────────┤
│ 1. Polls Google Quota API via local admin service                      │
│ 2. Calculates TRUE QUOTA: min(5h_bucket, weekly_bucket)                │
│ 3. Detects active IDE account quota exhaustion (<= 2.0%)               │
│ 4. Selects the Pro account with highest available True Quota           │
│ 5. Gracefully restarts Antigravity IDE & injects fresh credentials     │
│ 6. Dispatches native macOS notification with sound ("Hero")            │
└────────────────────────────────────────────────────────────────────────┘
                                    │
                                    ▼
┌────────────────────────────────────────────────────────────────────────┐
│                 5-Minute Watchdog (com.antigravity.autopilot)          │
├────────────────────────────────────────────────────────────────────────┤
│ • Auto-heals crashed or zombie background daemons                      │
│ • Runs 5-hour rolling warm-ups to trigger rolling window refresh       │
│ • Automatically backs up config integrity                              │
└────────────────────────────────────────────────────────────────────────┘

The True Quota Formula

The mathematical foundation of the controller replaces naive percentage displays with an accurate bottleneck calculation:

$$\text{True Quota} = \min(\text{Bucket}{\text{5h}}, \text{Bucket}{\text{weekly}})$$

If an account shows:

  • 5-Hour Bucket: 100%
  • Weekly Bucket: 0.0%

Its calculated True Quota is strictly 0.0%. The candidate is immediately excluded from active selection and model protection rules are enforced, eliminating 429 cascade failures.

Quick Installation

Antigravity Autopilot is designed for seamless deployment on macOS:

1. Automated One-Line Setup

git clone https://github.com/yasircs4/antigravity-autopilot.git
cd antigravity-autopilot
chmod +x scripts/install.sh
./scripts/install.sh

2. Install as an Agent Skill

To equip autonomous coding agents (Claude Code, Codex, OpenCode, or Cursor):

mkdir -p ~/.agents/skills/antigravity-autopilot
cp -r skills/antigravity-autopilot/* ~/.agents/skills/antigravity-autopilot/

For Google Antigravity / Gemini CLI:

mkdir -p ~/.gemini/config/skills/antigravity-autopilot
cp -r skills/antigravity-autopilot/* ~/.gemini/config/skills/antigravity-autopilot/

Live Diagnostics via Doctor

The included diagnostic script inspects LaunchAgents, proxy connectivity, and live account quotas in real time:

python3 scripts/doctor.py

Sample output from active production:

=== 1. Checking LaunchAgents ===
  [PASS] com.antigravity.controller   (PID: 39727, Exit: 0)
  [PASS] com.antigravity.autopilot    (PID: -, Exit: 0)
  [PASS] com.antigravity.notifier     (PID: 67890, Exit: 0)

=== 2. Checking Local Antigravity Tools Proxy (port 8045) ===
  [PASS] Health endpoint reachable: {'status': 'ok', 'version': '4.7.4'}

=== 3. Account True Quotas & Active Selection ===
  account1@gmail.com   | True Gemini:  23.3% | 5h:  99.9% | Weekly:  23.3% | HEALTHY 
  account2@gmail.com   | True Gemini:   0.5% | 5h: 100.0% | Weekly:   0.5% | DEPLETED
  account3@gmail.com   | True Gemini:   0.0% | 5h: 100.0% | Weekly:     0% | DEPLETED
  account4@gmail.com   | True Gemini:  37.4% | 5h:  89.5% | Weekly:  37.4% | HEALTHY  [ACTIVE IDE]

Real-World Production Proof

During live testing, the active account najeepyasir dropped to 0.2% quota. Within 60 seconds, the controller identified the exhaustion, disqualified depleted accounts, verified that standby account yasir.najeeb.official had reset to 70.6%, executed the credential injection, relaunched the IDE, and notified the desktop:

[INFO] Active account: najeepyasir@gmail.com | True Gemini: 0.2% (5h: 79.9%, Weekly: 0.2%)
[WARN] 🚨 ACTIVE ACCOUNT DEPLETED: najeepyasir@gmail.com is at 0.2% (<= 2.0%)! Triggering rotation...
[INFO] ✅ Selected best replacement account: yasir.najeeb.official@gmail.com (70.6% True Gemini quota)
[INFO] Executing switch via API: accountId=f7e1c14c-0509-4252-bfb7-4558307ed8f1 targetIde=null...
[INFO] 🎉 SUCCESS: Switched active account from najeepyasir@gmail.com to yasir.najeeb.official@gmail.com (70.6% quota)!
[INFO] Active account: yasir.najeeb.official@gmail.com | True Gemini: 68.7% | Threshold: 2.0%

The complete code, automation daemons, and documentation are available on GitHub.

AIAgent SkillsGoogle AntigravityDeveloper ToolsAutomationmacOS