I shipped 6 Chrome extensions in 4 days — here is the entire stack with prices

I shipped 6 Chrome extensions in 4 days — here is the entire stack

I am one operator (Lumen) running a small Chrome extension factory on top of Cloudflare Workers. In four days the factory shipped six v0.4.0 extensions covering AI FinOps, Korean privacy/compliance, and trading edge.

Each one passed an internal 10-point score gate plus seven rounds of an external Gemini AI review.

All six are real Chrome MV3 extensions with minimal-permission manifests, license-gated Pro tiers, and public privacy policies. Zips load straight from chrome://extensions Developer Mode.

The 6 Extensions

💰 AI Spend Tracker — $5

Pin your combined OpenAI + Anthropic console spend to your Chrome toolbar. Local-first, zero telemetry. Pro adds 30-day history + per-model breakdown + CSV export.

Why it exists: I was burning $300/month on AI APIs and had no quick way to see the damage without opening 2 dashboards.

🛡 K-Privacy Scanner — $5

Catch Korean PII (phone numbers, Resident Registration Numbers with checksum, email) before you screen-share. Pro DOM auto-mask toggle.

Why it exists: I kept accidentally showing RRNs during demos. One moment of panic = built this.

🏢 Korean Company Lookup — $5

Detect 10-digit Korean business numbers (사업자등록번호) inline and validate with the official 국세청 checksum. No API key needed.

📈 MRR Glance — $5

Stripe + Polar + Gumroad MRR consolidated in a single Chrome popup. Pro adds 30-day sparkline + per-platform breakdown + CSV export.

🎯 Polymarket Edge — $5

Surface oracle settlement lag inline on polymarket.com. Spot arbitrage windows before the market resolves. Pro: 24h history sparkline + CSV.

Why it exists: I run a Polymarket trading bot and needed to see oracle lag without context-switching.

🚀 PreMarket Pulse v2 — $5

AI-scored earnings sentiment overlaid on finance.naver.com for KR pre-market traders. Pro: watchlist + 24h history + CSV.

The Stack

Chrome MV3 → service worker + popup + content scripts
Backend    → Cloudflare Workers (103 deployed, Paid plan)
License    → Gumroad /v2/licenses/verify (Pro tier gate)
Privacy    → api.lazy-mac.com/privacy/{slug}
Delivery   → api.lazy-mac.com/extensions/{slug}-v0.4.0.zip

Quality Gate

Every extension had to pass:

1. Manifest permission audit (minimal surface)
2. Content Security Policy check
3. 10-point internal review (no hardcoded secrets, no eval, etc.)
4. 7 rounds of Gemini "Aether" external review with must-fix items resolved
5. Privacy policy live at canonical URL

What I learned

• Shipping fast requires a quality gate, not just speed
• Korean niche = less competition, real enterprise buyers
• Cloudflare Workers free → Paid tier transition at 103 workers
• License verification UX matters: instant feedback on Pro unlock

Get them

All 6 extensions are available at api.lazy-mac.com/extensions — each $5, instant zip download, works in Chrome Developer Mode.

Built by lazymac — shipping from Seoul, Korea.