SaaS boilerplate + live demo for streaming Claude extended-thinking UIs, sold to devs who need to ship agent interfaces fast

Customer: Indie dev or small agency building AI-powered SaaS products who needs to demo reasoning-aware chat to investors/clients within days, not weeks — has TypeScript skills but hasn’t wired extended thinking + streaming before

Problem: Wiring Claude extended-thinking tokens into a polished streaming UI takes 2-3 days of SDK spelunking, edge-case handling, and Tailwind polish. Most devs fake it with spinners, which kills demo credibility with technical audiences.

Pricing: one-time — $800 one-time sales in month 1 (targeting 16 sales at $49), then layer in $29/mo hosted demo tier by month 3

Why now

Claude Sonnet 4.5 extended thinking just shipped. Vercel AI SDK added streaming reasoning token support. Zero polished open templates exist yet — 2-4 week window before GitHub clones flood the space.

Go-to-market

1. Ship working Next.js repo on GitHub (free tier), post detailed build thread on X/Twitter tagging @vercel @anthropic — target 200 stars in week 1
2. Post 60-second Loom demo on Hacker News Show HN: show thinking indicator driven by real concurrent reasoning tokens vs spinner hack side-by-side
3. List $49 ‘pro template’ on Gumroad with: auth scaffold, rate limiting, usage metering, deploy-to-Vercel button — link from GitHub README
4. DM 20 devs posting ‘building with Claude’ on X, offer free license for honest tweet/review

Moat (or lack thereof)

No moat. Anthropic or Vercel ship an official template and this dies. Real value is first-mover timing + quality of DX polish. Treat it as a $1-3k windfall product, not a business.