antigravity-seo: Go engine and token-efficient SEO audits for Antigravity CLI Developer Angelotc released antigravity-seo, a Go-based SEO and Generative Engine Optimization suite for Google Antigravity that replaces Python/Playwright runtimes with a single Go binary called seo-engine. The project claims 85–90% cost savings on full site audits versus claude-seo with Claude Opus 5, citing Gemini 3.8 Flash pricing of $0.75/$3.75 per 1M tokens against Opus 5's $5.00/$25.00 per 1M, and offers 21 Antigravity skills plus native search_web and read_url_content grounding. The suite installs to ~/.gemini/config/plugins/antigravity-seo and includes commands for headers, audit, page, report, schema, images, content, hreflang, llms.txt, and sitemap checks. An SEO and Generative Engine Optimization GEO suite for Google Antigravity , powered by Go. Note Lineage : Inspired by claude-seo https://github.com/AgriciDaniel/claude-seo by Daniel Agrici. Antigravity SEO replaces Python/Playwright runtimes with a single Go binary seo-engine and native agent tools search web , read url content . | Dimension | claude-seo + Claude Opus 5 | antigravity-seo + Gemini 3.8 Flash | Advantage | |---|---|---|---| | Input / Output Token Cost | $5.00 / $25.00 per 1M | $0.75 / $3.75 per 1M | 6.7x cheaper | | Single Page Audit ~50k in / 10k out | ~$0.50 | ~$0.075 | ~85% savings | | Full Site Audit 20 pages, ~400k in / 80k out | ~$4.00 – $8.00+ | ~$0.60 | ~85% – 90% savings | | Multi-Agent Swarm Crawls | Not supported single model tier | ~$0.12 – $0.20 via flash lite | ~25x – 40x cheaper | | Live SERP & Crawl Data | Optional paid SaaS MCPs DataForSEO, Firecrawl, Ahrefs | ✅ Native search web & Common Crawl | Zero paid subscriptions | | Engine Runtime | Python venv, pip dependencies, Playwright | ✅ Single Go binary seo-engine | Zero dependencies, 10ms startup | | Google Search Console | External Node/Python scripts | ✅ Native RSA JWT exchange | Built-in auth & queries | Pricing based on September 2026 rates. Multi-agent crawls fan out to flash lite subagents for penny-scale execution. 1. Token Economics : Claude Opus 5 thinking traces bill at $25/1M, making multi-page audits costly $4–$8+ . Gemini 3.8 Flash $0.75 / $3.75 cuts costs by 85–90% ~$0.60 , while flash lite subagent swarms handle raw crawling for <$0.15. 2. Zero-Dependency Go Engine : seo-engine is a standalone binary with 10ms execution, eliminating Python venvs, pip modules, and headless browser daemons. 3. Native Grounding : Live Google SERP analysis and markdown extraction use Antigravity's built-in search web and read url content without paid third-party MCPs. 4. Built-in GSC & Backlinks : Direct RSA/PKCS8 JWT authentication for Google Search Console and keyless Common Crawl CDX index lookups. 5. Native A4 PDF Reports : Built-in PDF report generation --pdf via fpdf matching executive print standards with zero external dependencies. php flowchart LR User User -- Skills "21 Antigravity Skills\nAudit • Schema • Content • GEO • Backlinks" Skills -- Engine "Go Engine seo-engine \nFast audits, crawler, GSC, & PDF generation" Skills -- Native "Native Grounding\nsearch web & read url content" Engine -- Output "Deliverables\nCLI • JSON • Enterprise A4 PDF" macOS / Linux: curl -fsSL https://raw.githubusercontent.com/angelotc/antigravity-seo/main/install.sh | bash Windows PowerShell : irm https://raw.githubusercontent.com/angelotc/antigravity-seo/main/install.ps1 | iex Installs the plugin to ~/.gemini/config/plugins/antigravity-seo and symlinks seo-engine into your PATH. git clone https://github.com/angelotc/antigravity-seo.git cd antigravity-seo bash install.sh On Windows: powershell -ExecutionPolicy Bypass -File install.ps1 Verify anytime with: seo-engine doctor | Command | Purpose | |---|---| | headers